Droplet ejection apparatus, method of cleaning droplet ejection head, and storage medium

Abstract

To efficiently clean a discharge surface of a liquid droplet discharge head.SOLUTION: A liquid discharge apparatus according to an aspect of the present disclosure includes a liquid discharge head, a cleaning unit, and a controller. The droplet discharge head discharges a functional liquid onto the surface of the workpiece. The cleaning unit cleans a droplet discharge surface of the droplet discharge head. The cleaning unit includes a contact member that comes into contact with the ejection surface, and a sliding mechanism that slides the contact member with respect to the ejection surface. The control unit controls the cleaning unit to execute a contact cleaning process of cleaning the ejection surface by bringing the contact member into contact with the ejection surface without sliding the contact member on the ejection surface, and a sliding cleaning process of cleaning the ejection surface by sliding the contact member on the ejection surface cleaned by the contact cleaning process.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to a droplet ejection device, a method for cleaning a droplet ejection head, and a storage medium. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known an inkjet recording apparatus that cleans the ejection surface of an inkjet head by wiping the ejection surface with a wiping member to which a cleaning liquid has been applied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-009394 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can efficiently clean the ejection surface of a droplet ejection head. [Means for solving the problem]

[0005] A liquid ejection device according to one aspect of the present disclosure includes a droplet ejection head, a cleaning unit, and a control unit. The droplet ejection head ejects a functional liquid onto the surface of a workpiece. The cleaning unit cleans the droplet ejection surface of the droplet ejection head. The cleaning unit includes a contact member that contacts the ejection surface and a sliding mechanism that slides the contact member against the ejection surface. The control unit controls the cleaning unit to perform a contact cleaning process that cleans the ejection surface by bringing the contact member into contact with the ejection surface without sliding against it, and a sliding cleaning process that cleans the ejection surface by sliding the contact member against the ejection surface cleaned by the contact cleaning process. [Effects of the Invention]

[0006] According to the present disclosure, the ejection surface of the droplet ejection head can be efficiently cleaned. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic side view of a droplet ejection device according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram of the droplet ejection device according to the embodiment, viewed from above. [Figure 3] FIG. 3 is a schematic diagram showing an example of the configuration of the first cleaning unit according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram showing an example of the configuration of the second cleaning unit according to the embodiment. [Figure 5] FIG. 5 is a schematic diagram showing a configuration example of a drying unit according to an embodiment. [Figure 6] FIG. 6 is an explanatory diagram of a processing operation performed by the droplet ejection device according to the embodiment. [Figure 7] FIG. 7 is an explanatory diagram of a processing operation performed by the droplet ejection device according to the embodiment. [Figure 8] FIG. 8 is an explanatory diagram of a processing operation performed by the droplet ejection device according to the embodiment. [Figure 9] FIG. 9 is a diagram showing an example of dirt adhering to the ejection surface of the droplet ejection head according to the embodiment. [Figure 10] FIG. 10 is an explanatory diagram of the contact cleaning process executed by the control unit according to the embodiment. [Figure 11] FIG. 11 is an explanatory diagram of the sliding cleaning process executed by the control unit according to the embodiment. [Figure 12] FIG. 12 is a flowchart showing a series of cleaning process steps executed by the control unit according to the embodiment. [Figure 13] FIG. 13 shows a first modified example of the configuration of the cleaning unit according to the embodiment. [Figure 14] FIG. 14 shows a second modified example of the configuration of the cleaning unit according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Below, a detailed description will be given of a droplet ejection device, a droplet ejection head cleaning method, and a storage medium (hereinafter referred to as "embodiments") according to the present disclosure, with reference to the drawings. Note that the present disclosure is not limited to these embodiments. Furthermore, the embodiments can be appropriately combined as long as the processing content is not contradictory. Furthermore, the same components in the following embodiments are given the same reference numerals, and redundant explanations will be omitted.

[0009] Inkjet droplet ejection devices that eject droplets of functional liquid have been known as devices for forming images on a substrate using functional liquid. Droplet ejection devices are used in the manufacture of flat panel displays such as organic electroluminescence (EL) displays, plasma displays, and field emission displays.

[0010] A typical inkjet droplet ejection device includes a carriage equipped with a droplet ejection head that ejects droplets of functional liquid, a work stage on which a workpiece is mounted, and a movement mechanism that moves the work stage in a certain direction. While the work stage is moved relative to the carriage, functional liquid is ejected from the droplet ejection head onto banks that have been formed in advance on the workpiece, thereby performing drawing on the workpiece.

[0011] When the above-described drawing process is repeated, solid matter may adhere to the ejection surface of the droplet ejection head due to factors such as precipitation of components of the functional liquid. If solid matter adheres to the ejection surface, the ejected droplets may bend or the nozzles may become clogged, which may prevent the functional liquid from landing properly on the bank. For this reason, conventional droplet ejection devices are provided with a cleaning unit that wipes the ejection surface of the droplet ejection head with a wiping member, and maintenance of the droplet ejection head is performed periodically.

[0012] Patent Document 1 discloses a wiping unit that includes a wiping sheet, a supply reel that pays out the wiping sheet, a take-up reel that winds up the wiping sheet, a wiping roller that presses the wiping sheet against the discharge surface, and a cleaning liquid supply unit that supplies cleaning liquid to the wiping sheet.

[0013] However, when two types of dirt, for example, thin-film dirt and droplet-like dirt, adhere to the ejection surface, it is difficult to efficiently remove such dirt with the wiping unit described in Patent Document 1. While it is conceivable to repeatedly slide a wiping sheet against the ejection surface to remove such dirt, this may increase the time required for cleaning and may also damage the ejection surface.

[0014] Therefore, there is a need for a technology that can efficiently clean the ejection surface of a droplet ejection head.

[0015] <Configuration of droplet ejection device> First, the configuration of the droplet discharge device according to this embodiment will be described with reference to Figs. 1 and 2. Fig. 1 is a schematic side view of the droplet discharge device according to this embodiment. Fig. 2 is a schematic top view of the droplet discharge device according to this embodiment. In the following, the main scanning direction of the workpiece W is defined as the X-axis direction, the sub-scanning direction perpendicular to the main scanning direction is defined as the Y-axis direction, and the vertical direction perpendicular to the X-axis and Y-axis directions is defined as the Z-axis direction. The workpiece W is, for example, a glass substrate used in a flat panel display.

[0016] 1 and 2, the droplet discharge device 1 has an X-axis table 10 that extends in the main scanning direction (X-axis direction) and moves a workpiece W in the main scanning direction, and a pair of Y-axis tables 11, 11 that straddle the X-axis table 10 and extend in the sub-scanning direction (Y-axis direction). A pair of X-axis guide rails 12, 12 are provided on the upper surface of the X-axis table 10 and extend in the X-axis direction, and each X-axis guide rail 12 is provided with an X-axis linear motor (not shown) as a movement mechanism. A Y-axis guide rail 13 is provided on the upper surface of each Y-axis table 11 and extends in the Y-axis direction, and each Y-axis guide rail 13 is provided with a Y-axis linear motor (not shown) as a movement mechanism.

[0017] A carriage unit 20 and a first imaging unit 30 are provided on the pair of Y-axis tables 11, 11. A workpiece stage 40, a flushing unit 50, and a discharge inspection unit 60 are provided on the X-axis table 10. The workpiece stage 40, the flushing unit 50, and the discharge inspection unit 60 are arranged in this order in the X-axis direction. A maintenance unit 80 is provided outside the X-axis table 10 (on the negative Y-axis side) and between the pair of Y-axis tables 11, 11. Each unit will be described in detail below.

[0018] A plurality of, for example, ten carriage units 20 are provided on the Y-axis table 11. Each carriage unit 20 has a carriage plate 21, a carriage rotation mechanism 22, a carriage 23, and a droplet ejection head 24.

[0019] The carriage plate 21 is attached to a Y-axis guide rail 13 and is movable in the Y-axis direction by a Y-axis linear motor provided on the Y-axis guide rail 13. Note that it is also possible to move a plurality of carriage plates 21 as a unit in the Y-axis direction.

[0020] A carriage rotation mechanism 22 is provided in the center of the underside of the carriage plate 21, and a carriage 23 is detachably attached to the lower end of the carriage rotation mechanism 22. The carriage 23 is rotatable in the θ direction by the carriage rotation mechanism 22. A carriage alignment camera (not shown) that captures an image of the carriage 23 is provided on the work stage 40. The position of the carriage 23 in the θ direction is corrected by the carriage rotation mechanism 22 based on the image captured by the carriage alignment camera.

[0021] A plurality of droplet ejection heads 24 are arranged in the X-axis direction on the underside of the carriage 23. In this embodiment, for example, three droplet ejection heads 24 are provided in the X-axis direction and two droplet ejection heads 24 in the Y-axis direction, i.e., a total of six droplet ejection heads 24 are provided. A plurality of ejection nozzles (not shown) are formed on the underside of each droplet ejection head 24, i.e., the ejection surface 24a, and droplets of functional liquid are ejected from the ejection nozzles onto the surface of the workpiece W.

[0022] The functional liquid ejected from the droplet ejection head 24 is supplied from a treatment liquid supply unit 25. The treatment liquid supply unit 25 has a functional liquid supply source 26a that supplies a functional liquid such as ink, and a functional liquid supply pipe 26b that serves as a flow path for the functional liquid. The treatment liquid supply unit 25 also has a solvent supply source 27a that supplies a solvent for the functional liquid, and a solvent supply pipe 27b that serves as a flow path for the solvent. The treatment liquid supply unit 25 also has an alcohol supply source 28a that supplies an alcohol-based moisturizing liquid, and an alcohol supply pipe 28b that serves as a flow path for the alcohol-based moisturizing liquid. The solvent for the functional liquid supplied from the solvent supply source 27a is an example of a first moisturizing liquid. The alcohol-based moisturizing liquid supplied from the alcohol supply source 28a is an example of a second moisturizing liquid.

[0023] Examples of functional liquids that can be used include inks in which organic materials such as OLED (Organic Light Emitting Diode) ink are dissolved in a solvent, inks in which inorganic materials such as QD (Quantum Dot) ink are dispersed in a solvent, and paints in which fine particles such as nanoparticles are dispersed in a solvent. Note that, as the alcohol-based moisturizing liquid, it is preferable to use a solution containing one or more organic solvents selected from, for example, ethanol, n-propanol, and isopropanol.

[0024] The functional liquid supply pipe 26b, the solvent supply pipe 27b, and the alcohol supply pipe 28b are each connected to a junction pipe 29. The valves of the pipes 26b, 27b, and 28b are appropriately opened and closed by a control unit 150 (described later), thereby supplying one of the treatment liquids, i.e., the functional liquid, the solvent for the functional liquid, and the alcohol-based moisturizing liquid, to the junction pipe 29. The junction pipe 29 is connected to the carriage unit 20 so as to supply the treatment liquid to the carriage 23. The configuration of the treatment liquid supply unit 25 is not particularly limited, and for example, the functional liquid supply pipe 26b, the solvent supply pipe 27b, and the alcohol supply pipe 28b may be connected directly to the carriage unit 20 without providing the junction pipe 29.

[0025] The first imaging unit 30 has a discharge inspection camera 31 as an imaging section for discharge inspection, and a drawing inspection camera 32 as an imaging section for drawing inspection. The discharge inspection camera 31 and the drawing inspection camera 32 are arranged opposite each other in the X-axis direction with the carriage 23 (droplet ejection head 24) in between. The discharge inspection camera 31 is arranged on the positive X-axis side of the carriage 23, i.e., on the flushing unit 50 side. The drawing inspection camera 32 is arranged on the negative X-axis side of the carriage 23, i.e., on the workpiece stage 40 side.

[0026] The discharge inspection camera 31 captures images of dots formed by droplets that have been inspected and discharged onto an inspection sheet 62 (described later) of the discharge inspection unit 60. The discharge inspection camera 31 is supported by a base 33 that is provided on the side of the Y-axis table 11 (of the pair of Y-axis tables 11) that is on the X-axis positive side. A movement mechanism (not shown) that moves the discharge inspection camera 31 is provided on the base 33, and the discharge inspection camera 31 is movable in the Y-axis direction. When the discharge inspection unit 60 is guided directly below the trajectory of the discharge inspection camera 31 moving in the Y-axis direction, the discharge inspection camera 31 moves in the Y-axis direction, thereby capturing images of droplets that have landed on the inspection sheet 62 placed on the discharge inspection unit 60.

[0027] The drawing inspection camera 32 captures an image of the drawing state of the droplets discharged onto the workpiece W. The drawing inspection camera 32 is supported by a base 34 provided on the side of the Y-axis table 11 on the negative X-axis side of the pair of Y-axis tables 11. A movement mechanism (not shown) for moving the drawing inspection camera 32 is provided on the base 34, and the drawing inspection camera 32 is freely movable in the Y-axis direction. When the workpiece stage 40 is guided directly below the trajectory of the drawing inspection camera 32 moving in the Y-axis direction, the drawing inspection camera 32 moves in the Y-axis direction to capture an image of the drawing state of a pattern or the like drawn by the droplets discharged onto the workpiece W on the workpiece stage 40.

[0028] The workpiece stage 40 is, for example, a vacuum suction stage, on which the workpiece W is placed by suction. The workpiece stage 40 is supported so as to be rotatable in the θ direction by a stage rotation mechanism 41 provided on the underside of the workpiece stage 40. A workpiece alignment camera (not shown) is provided above the workpiece stage 40, on the negative X-axis side of the Y-axis table 11, to capture an image of the alignment mark of the workpiece W on the workpiece stage 40. Then, based on the image captured by the workpiece alignment camera, the stage rotation mechanism 41 corrects the position of the workpiece W placed on the workpiece stage 40 in the θ direction.

[0029] The workpiece stage 40 and the stage rotating mechanism 41 are supported by a first X-axis slider 42 provided on the underside of the stage rotating mechanism 41. The first X-axis slider 42 is attached to an X-axis guide rail 12, and is movable in the X-axis direction by an X-axis linear motor provided on the X-axis guide rail 12. The workpiece stage 40 (workpiece W) is also movable in the X-axis direction along the X-axis guide rail 12 by the first X-axis slider 42.

[0030] The flushing unit 50 is a unit that receives waste discharged droplets from the droplet discharge head 24. The flushing unit 50 has a plurality of, for example, ten flushing recovery stages 51 arranged in the Y-axis direction. The number of flushing recovery stages 51 is the same as the number of carriages 23.

[0031] The flushing collection table 51 has an open top, and when the flushing collection table 51 is guided to a position directly below the corresponding carriage 23, droplets are discharged (flushed) from the droplet discharge head 24 of the carriage 23, and the flushing collection table 51 receives and stores the droplets. In other words, a flushing operation is performed before drawing with droplets on the workpiece W, and the droplets resulting from the flushing are collected by the flushing collection table 51.

[0032] The discharge inspection unit 60 is a unit that receives inspection discharges from the droplet discharge head 24. The discharge inspection unit 60 is provided with an inspection table 61 that extends in the Y-axis direction. An inspection sheet 62 with a film coating on its surface is placed on the upper surface of the inspection table 61. The inspection sheet 62 placed on the inspection table 61 is designed so that when the inspection table 61 is guided to directly below the droplet discharge head 24, the droplets discharged from the droplet discharge head 24 land on it.

[0033] The flushing unit 50 and the discharge inspection unit 60 are mounted on a second X-axis slider 70. The second X-axis slider 70 is attached to an X-axis guide rail 12 and is movable in the X-axis direction by an X-axis linear motor provided on the X-axis guide rail 12. The flushing unit 50 and the discharge inspection unit 60 are also movable in the X-axis direction along the X-axis guide rail 12 by the second X-axis slider 70.

[0034] The maintenance unit 80 performs maintenance on the droplet ejection head 24 and eliminates ejection defects of the droplet ejection head 24. The maintenance unit 80 has a first cleaning unit 90A, a second cleaning unit 90B, a suction unit 110, a drying unit 120, and a second imaging unit 130.

[0035] The above units of the maintenance unit 80 are arranged in the positive direction of the Y axis in the following order: suction unit 110, first cleaning unit 90A, drying unit 120, second cleaning unit 90B, and second imaging unit 130. Furthermore, the above units are arranged so as to be located below the carriage 23.

[0036] The first cleaning unit 90A is a unit that cleans the ejection surface 24a of the droplet ejection head 24, on which a plurality of ejection nozzles are formed. The first cleaning unit 90A has a contact roller 91A and a first contact member 92A. The first cleaning unit 90A is used for a contact cleaning process, which will be described later. The specific configuration of the first cleaning unit 90A will be described later with reference to FIG. 3.

[0037] Similar to the first cleaning unit 90A, the second cleaning unit 90B is a unit that cleans the ejection surface 24a of the droplet ejection head 24, on which a plurality of ejection nozzles are formed. The second cleaning unit 90B has a contact roller 91B and a second contact member 92B. The second cleaning unit 90B is used for a sliding cleaning process that is performed after the contact cleaning process performed by the first cleaning unit 90A. The specific configuration of the second cleaning unit 90B will be described later with reference to FIG. 4.

[0038] The suction unit 110 is a unit that sucks the treatment liquid from the droplet discharge head 24. The suction unit 110 has a plurality of, for example, ten, divided suction units 111 arranged in the Y-axis direction. The number of divided suction units 111 is the same as the number of carriages 23. Each divided suction unit 111 sucks the droplet discharge head 24 of the corresponding carriage 23, forcibly discharging the treatment liquid from the discharge nozzle (not shown) of the droplet discharge head 24. Furthermore, when the droplet discharge device 1 is in a resting state, each divided suction unit 111 comes into close contact with the discharge surface 24a of the droplet discharge head 24 to prevent the treatment liquid from drying out.

[0039] 1 described above, the valves of the functional liquid supply pipe 26b and the alcohol supply pipe 28b are closed, and only the valve of the solvent supply pipe 27b is open, and suction is performed in this state, whereby the solvent is drawn into the droplet discharge head 24. This fills the droplet discharge head 24 with the solvent, and the functional liquid that filled the droplet discharge head 24 before suction can be replaced with the solvent. Similarly, if suction is performed in this state with the valves of the functional liquid supply pipe 26b and the solvent supply pipe 27b closed, and only the valve of the alcohol supply pipe 28b is open, the solvent that filled the droplet discharge head 24 can be replaced with alcohol. Note that such replacement of the processing liquid may be achieved using other means than suction by the suction unit 110.

[0040] The drying unit 120 is a unit that dries the ejection surface 24a of the droplet ejection head 24. The drying unit 120 is disposed between the first cleaning unit 90A and the second cleaning unit 90B along the Y-axis direction. FIG. 5 is a schematic diagram showing an example of the configuration of the drying unit 120 according to this embodiment. The drying unit 120 includes, for example, an air blower 121. The air blower 121 dries the ejection surface 24a by blowing hot air onto the ejection surface 24a. This makes it possible to dry liquid such as a solvent for the functional liquid present on the ejection surface 24a.

[0041] The drying unit 120 may be any unit capable of drying the discharge surface 24a, and the configuration of the drying unit 120 is not limited to the above example. For example, the drying unit 120 may dry the discharge surface 24a by blowing N2 gas or the like from the blower 121 instead of hot air. The drying unit 120 may also include a UV (Ultra Violet) irradiation unit instead of the blower 121. In this case, the drying unit 120 may dry the discharge surface 24a using UV irradiated from the UV irradiation unit.

[0042] The second imaging unit 130 is a unit that captures an image of the ejection surface 24a of the droplet ejection head 24. The second imaging unit 130 is disposed, for example, on the positive Y-axis side of the second cleaning unit 90B. The second imaging unit 130 captures an image of the ejection surface 24a that has been cleaned by the first cleaning unit 90A and the second cleaning unit 90B.

[0043] Next, the configuration of the first cleaning unit 90A will be described in more detail. Figure 3 is a schematic diagram showing an example of the configuration of the first cleaning unit 90A according to this embodiment.

[0044] As shown in FIG. 3, the first cleaning unit 90A has a first reel 93A, a guide roller 94A, the above-mentioned contact roller 91A, and a second reel 95A as a sliding mechanism that slides the first contact member 92A against the discharge surface 24a.

[0045] The first contact member 92A is a member that comes into contact with the ejection surface 24a to clean the ejection surface 24a. The first contact member 92A may be, for example, a sheet made of polyester fiber, polypropylene fiber, or a fiber with a laminated structure of polyester and polyamide. In this case, the first contact member 92A may be an elongated member having a cotton-like fiber structure on its surface and having a longitudinal direction in the Y-axis direction. Note that, although the first contact member 92A in this embodiment is an elongated member, the contact member used to clean the ejection surface 24a is not limited to an elongated member. This point will be described later.

[0046] The first reel 93A and the second reel 95A are arranged with the first contact member 92A wound around each of the longitudinal ends of the first contact member 92A. The first reel 93A, guide roller 94A, contact roller 91A, and second reel 95A are an example of a sliding mechanism, and can feed the first contact member 92A along the Y-axis direction by being rotationally driven under the control of a control unit 150 (described later). This allows the first contact member 92A to slide against the ejection surface 24a of the droplet ejection head 24. The configuration of the sliding mechanism that slides the first contact member 92A against the ejection surface 24a is not particularly limited, and a known configuration may be used, for example.

[0047] The contact roller 91A is provided so as to be able to move up and down relative to the ejection surface 24a of the droplet ejection head 24. When cleaning the ejection surface 24a, the contact roller 91A rises relative to the ejection surface 24a and cleans the ejection surface 24a by pressing the first contact member 92A against the ejection surface 24a. Note that when cleaning the ejection surface 24a, the carriage 23 may be lowered so that the ejection surface 24a is pressed against the first contact member 92A.

[0048] A humidifying liquid supply unit 96 is provided between the contact roller 91A and the guide roller 94A to supply humidifying liquid to the first contact member 92A. The humidifying liquid supply unit 96 has a solvent supply source 97a that supplies a solvent for the functional liquid as the first humidifying liquid, and a solvent supply pipe 97b that serves as a flow path for the solvent. The humidifying liquid supply unit 96 also has an alcohol supply source 98a that supplies an alcohol-based humidifying liquid as the second humidifying liquid, and an alcohol supply pipe 98b that serves as a flow path for the alcohol-based humidifying liquid. The humidifying liquid supply unit 96 also has a water supply source 99a that supplies a humidifying liquid whose main component is water as the third humidifying liquid, and a water supply pipe 99b that serves as a flow path for the humidifying liquid whose main component is water.

[0049] As the alcohol-based moistening liquid, it is preferable to use a solution containing one or more organic solvents selected from ethanol, n-propanol, and isopropanol, similar to the alcohol-based moistening liquid supplied to the droplet ejection head 24. As the moistening liquid containing water as the main component, it is preferable to use pure water, for example.

[0050] The solvent supply pipe 97b, the alcohol supply pipe 98b, and the water supply pipe 99b are each connected to a junction pipe 100. The valves of the pipes 97b, 98b, and 99b are appropriately opened and closed by a control unit 150 (described later), thereby supplying any one of the following moistening liquids to the junction pipe 100: a solvent for the functional liquid, an alcohol-based moistening liquid, or a moistening liquid containing water as its main component. The junction pipe 100 is connected to a moistening liquid discharge nozzle 101A that discharges moistening liquid onto the first contact member 92A.

[0051] A plurality of humidifying liquid discharge nozzles 101A may be provided along the X-axis direction. The first contact member 92A is wetted with the humidifying liquid discharged from each humidifying liquid discharge nozzle 101A. Then, the first contact member 92A wetted with the humidifying liquid comes into contact with the discharge surface 24a of the droplet discharge head 24, thereby humidifying the discharge surface 24a.

[0052] The configuration of the humidifying liquid supply unit 96 is not particularly limited. For example, the solvent supply pipe 97b, the alcohol supply pipe 98b, and the water supply pipe 99b may be connected directly to the humidifying liquid discharge nozzle 101A without providing the junction pipe 100. The method of humidifying the discharge surface 24a is also not particularly limited. For example, the humidifying liquid may be discharged directly onto the discharge surface 24a from the humidifying liquid discharge nozzle 101A, which is arranged so that the discharge direction faces the discharge surface 24a.

[0053] Next, the configuration of the second cleaning unit 90B will be described with reference to Fig. 4. Fig. 4 is a schematic diagram showing an example configuration of the second cleaning unit 90B according to the embodiment. As shown in Fig. 4, the second cleaning unit 90B has a second contact member 92B that comes into contact with the discharge surface 24a to clean the discharge surface 24a. The second cleaning unit 90B also has a first reel 93B, a guide roller 94B, the aforementioned contact roller 91B, and a second reel 95B as a sliding mechanism that slides the second contact member 92B against the discharge surface 24a.

[0054] The first reel 93B, guide roller 94B, contact roller 91B, and second reel 95B provided in the second cleaning unit 90B have the same configuration as the first reel 93A, guide roller 94A, contact roller 91A, and second reel 95A provided in the first cleaning unit 90A, so their description will be omitted here.

[0055] The second contact member 92B is a member that comes into contact with the ejection surface 24a to clean the ejection surface 24a. The second contact member 92B may be, for example, a sheet made of polyester fiber, polypropylene fiber, or a fiber with a laminated structure of polyester and polyamide. In this case, the second contact member 92B may be an elongated member having a mesh-like fiber structure on its surface and with its longitudinal direction in the Y-axis direction. Note that, although the second contact member 92B in this embodiment is an elongated member, the contact member used to clean the ejection surface 24a is not limited to an elongated member. This point will be described later.

[0056] Here, the difference between the first contact member 92A and the second contact member 92B will be explained. As described above, the second contact member 92B is a mesh-like member, while the first contact member 92A is a cotton-like member. Therefore, the liquid absorbency of the first contact member 92A is higher than that of the second contact member 92B. Furthermore, the thickness of the first contact member 92A is greater than that of the second contact member 92B. The first contact member 92A can effectively absorb and remove droplet stains 241 (see FIG. 9) described below on the ejection surface 24a. On the other hand, the second contact member 92B can effectively wipe and remove thin film stains 242 (see FIG. 9) described below on the ejection surface 24a due to the mesh structure of its surface.

[0057] The droplet discharge device 1 has a control unit 150. The control unit 150 is, for example, a computer equipped with a CPU, memory, etc., and has a data storage unit (not shown). The data storage unit stores, for example, drawing data (bitmap data) for controlling the droplets discharged onto the workpiece W and for drawing a predetermined pattern on the workpiece W.

[0058] The control unit 150 also has a program storage unit (not shown). The program storage unit stores programs for controlling various processes in the droplet discharge device 1 and programs for controlling the operation of the drive system. For example, the control unit 150 controls the first cleaning unit 90A and the second cleaning unit 90B to perform cleaning of the discharge surface 24a of the droplet discharge head 24. The above programs may be recorded on a computer-readable storage medium and installed into the control unit 150 from the storage medium. The storage medium may be a temporary or non-temporary storage medium. Some or all of the programs may be implemented by dedicated hardware (circuit board).

[0059] <Workpiece processing in droplet ejection device> Next, we will explain workpiece processing performed using the droplet discharge device 1 configured as above. In the following explanation, on the X-axis table 10, the area on the negative X-axis side of the Y-axis table 11 will be referred to as the carry-in / out area A1, the area between the pair of Y-axis tables 11, 11 will be referred to as the processing area A2, and the area on the positive X-axis side of the Y-axis table 11 will be referred to as the standby area A3. In addition, the area on the negative Y-axis side of the X-axis table 10 between the pair of Y-axis tables 11, 11 will be referred to as the maintenance area A4.

[0060] First, the workpiece stage 40 is placed in the carry-in / out area A1, and the workpiece W carried into the droplet discharge device 1 by a transport mechanism (not shown) is placed on the workpiece stage 40. Next, a workpiece alignment camera (not shown) captures an image of the alignment mark of the workpiece W on the workpiece stage 40. Then, based on the captured image, the stage rotation mechanism 41 corrects the position of the workpiece W placed on the workpiece stage 40 in the θ direction, and the workpiece W is aligned (step S1).

[0061] Thereafter, the first X-axis slider 42 moves the workpiece stage 40 from the carry-in / out area A1 to the processing area A2. In the processing area A2, droplets are ejected from the droplet ejection head 24 onto the workpiece W that has moved below the droplet ejection head 24. Furthermore, as shown in FIG. 6, the workpiece stage 40 is further moved toward the waiting area A3 so that the entire surface of the workpiece W passes below the droplet ejection head 24. Then, the workpiece W is moved back and forth in the X-axis direction, and the carriage unit 20 is moved appropriately in the Y-axis direction, to draw a predetermined pattern on the workpiece W (step S2).

[0062] Thereafter, the workpiece stage 40 is moved from the waiting area A3 to the carry-in / out area A1. During this movement of the workpiece stage 40, the drawing inspection camera 32 is moved appropriately in the Y-axis direction, and the drawing inspection camera 32 captures an image of the entire surface of the workpiece W on the workpiece stage 40, i.e., the state of the pattern drawn by the droplets discharged onto the workpiece W. The captured image is output to the control unit 150, which then inspects for defects in the drawing state, such as film unevenness, based on the captured image. If the inspection results indicate that the drawing state is defective, feedback control is performed, for example, on the discharge of droplets from the droplet discharge head 24 (step S3).

[0063] When the workpiece stage 40 moves to the carry-in / out area A1, the workpiece W for which the drawing process has been completed is carried out from the droplet discharge device 1. Subsequently, the next workpiece W is carried into the droplet discharge device 1, and the alignment of the workpiece W in the above-mentioned step S1 is performed (step S4).

[0064] While the drawing state is being inspected in step S3 and the workpiece W is being loaded and unloaded in step S4, the second X-axis slider 70 moves the flushing unit 50 and the discharge inspection unit 60 from the standby area A3 to the processing area A2, along with the movement of the workpiece stage 40. In the processing area A2, the inspection sheet 62 of the discharge inspection unit 60 is placed below the droplet discharge head 24, and droplets are inspected and discharged from the droplet discharge head 24 onto the inspection sheet 62 (step S5).

[0065] Then, the flushing unit 50 and the discharge inspection unit 60 are moved in the positive direction of the X-axis, and the inspection sheet 62 of the discharge inspection unit 60 is positioned below the discharge inspection camera 31, and the flushing recovery table 51 of the flushing unit 50 is positioned below the droplet discharge head 24.

[0066] The discharge inspection camera 31 is then moved appropriately in the Y-axis direction, and the discharge inspection camera 31 captures an image of the landing dots of the droplets that have been inspected and discharged onto the inspection sheet 62. The captured image is output to the control unit 150, which then inspects the discharge nozzles of the droplet discharge heads 24 for defective discharge based on the captured image. If the inspection results in a discharge defect, such as nozzle dropout and deflection of droplets, the maintenance unit 80 performs maintenance on the droplet discharge heads 24. The specific processing performed by the maintenance unit 80 will be described later. Furthermore, if the diameter or position of the landing dots of the droplets is determined to be defective, for example, the bitmap data is corrected, and the discharge of droplets from the droplet discharge heads 24 is feedback-controlled.

[0067] Furthermore, while the image capturing process is being performed by the discharge inspection camera 31 and the discharge defect inspection is being performed by the control unit 150, the droplet discharge head 24 discharges droplets onto the flushing recovery table 51 (step S6).

[0068] As described above, steps S1 to S6 are performed on each workpiece W, and the series of workpiece processing is completed.

[0069] <Maintenance process> In the droplet discharge device 1, in addition to the normal processing of the workpiece W in the above steps S1 to S6, maintenance of the droplet discharge head 24 is performed as appropriate by the maintenance unit 80. In the following explanation, first, an outline of the maintenance process will be explained.

[0070] 7, when performing maintenance on the droplet ejection heads 24, the carriage unit 20 is moved from the processing area A2 to the maintenance area A4. In the maintenance area A4, first, each droplet ejection head 24 is placed above the divided suction units 111 of the suction unit 110. Then, a suction process is performed in which the divided suction units 111 are used to suck the functional liquid from the droplet ejection heads 24.

[0071] Next, as shown in FIG. 8, while the carriage unit 20 is moved in the positive direction of the Y axis, a series of cleaning processes are performed on the ejection surface 24a of the droplet ejection head 24 using the first cleaning unit 90A and the second cleaning unit 90B.

[0072] First, the carriage unit 20 is moved in the positive direction of the Y axis. When the droplet discharge head 24 of the carriage unit 20 reaches above the first cleaning unit 90A, a contact cleaning process is performed on the droplet discharge head 24. This removes droplet stains 241 (see FIG. 9) from the stains adhering to the discharge surface 24a. Thereafter, the carriage unit 20 moves further in the positive direction of the Y axis, and when the droplet discharge head 24 reaches above the drying unit 120, a drying process is performed on the droplet discharge head 24. This dries the liquid contained inside the thin film stains 242 (see FIG. 9) remaining on the discharge surface 24a.

[0073] Thereafter, the carriage unit 20 moves further in the positive direction of the Y axis, and when the droplet ejection head 24 reaches above the second cleaning unit 90B, a sliding cleaning process is performed on the droplet ejection head 24. This removes the thin film dirt 242 remaining on the ejection surface 24a.

[0074] Thereafter, the carriage unit 20 moves further in the positive direction of the Y axis, and when the droplet discharge head 24 reaches above the second imaging unit 130, an imaging process is performed on the droplet discharge head 24. As a result, an image of the discharge surface 24a after the contact cleaning process and the sliding cleaning process is captured.

[0075] After that, the carriage unit 20, which has completed the suction process by the suction unit 110 and the series of cleaning processes by the first cleaning unit 90A and the second cleaning unit 90B, is moved from the maintenance area A4 to the processing area A2, and maintenance of the droplet ejection head 24 is completed.

[0076] In the droplet discharge device 1 according to the embodiment, if the droplet stains 241 adhering to the discharge surface 24a have dried and adhered, the first cleaning unit 90A performs a humidification process to humidify the discharge surface 24a before the contact cleaning process. By performing the humidification process, the droplet stains 241 can be properly removed in the subsequent contact cleaning process.

[0077] Next, the humidification process and contact cleaning process performed by first cleaning unit 90A and the sliding cleaning process performed by second cleaning unit 90B in the maintenance process will be described in detail with reference to FIGS.

[0078] 9 is a diagram showing an example of stains adhering to the discharge surface 24a of the droplet discharge head 24 according to the embodiment. As shown in Fig. 9, before cleaning, the discharge surface 24a of the droplet discharge head 24 may have droplet stains 241, which are stains formed by droplets of functional liquid adhering thereto, and thin film stains 242, which are stains formed by the functional liquid becoming liquified and spreading out into a thin film and then adhering thereto.

[0079] FIG. 10 is an explanatory diagram of a contact cleaning process executed by the control unit 150 according to the embodiment. In the contact cleaning process, the control unit 150 controls the Y-axis linear motor to move the droplet discharge head 24 in the positive direction of the Y-axis at a first speed. The control unit 150 also controls the sliding mechanism (first reel 93A, second reel 95A, etc.) of the first cleaning unit 90A to feed the dried first contact member 92A in the positive direction of the Y-axis at a first speed. The contact roller 91A then presses the first contact member 92A into contact with the discharge surface 24a of the droplet discharge head 24. This allows the first contact member 92A to be in contact with the discharge surface 24a without sliding, thereby cleaning the entire surface of the discharge surface 24a (see FIG. 10).

[0080] In this contact cleaning process, the first contact member 92A, which has a cotton-like fiber structure on its surface, can absorb and remove the droplet stains 241 adhering to the ejection surface 24a. Furthermore, if cleaning were performed by sliding the contact member over the ejection surface 24a while in contact with it, as in the past, the functional liquid would be drawn from inside the ejection nozzles onto the surface of the ejection surface 24a, making it difficult to properly remove the droplet stains 241. In contrast, in the contact cleaning process, the first contact member 92A is brought into contact with the ejection surface 24a without sliding over it, making it difficult for the droplet stains 241 to be drawn from inside the ejection nozzles onto the surface of the ejection surface 24a. Therefore, this contact cleaning process can effectively absorb and remove the droplet stains 241.

[0081] In the maintenance process, the first cleaning unit 90A may be used to humidify the ejection surface 24a before the contact cleaning process. This humidification process is performed using the first contact member 92A wetted with humidifying liquid, following the same procedure as the contact cleaning process. As described above, the humidifying liquid is supplied to the first contact member 92A via the humidifying liquid ejection nozzle 101A. This humidification process allows the dried and adhered droplet stains 241 to be dissolved in the humidifying liquid, thereby more effectively removing the droplet stains 241. After performing the humidification process, the control unit 150 moves the carriage unit 20 in the negative Y-axis direction, positions the droplet ejection head 24 above the first cleaning unit 90A again, and then moves the carriage unit 20 in the positive Y-axis direction to perform the contact cleaning process.

[0082] FIG. 11 is an explanatory diagram of a sliding cleaning process executed by the control unit 150 according to the embodiment. In the contact cleaning process, following the contact cleaning process, the control unit 150 controls the Y-axis linear motor to move the droplet discharge head 24 in the positive direction of the Y axis at a first speed. The control unit 150 also controls the sliding mechanism (such as the first reel 93B and the second reel 95B) of the second cleaning unit 90B to feed the dried second contact member 92B in the negative direction of the Y axis at a second speed. The contact roller 91B then presses the second contact member 92B against the discharge surface 24a of the droplet discharge head 24. This causes the second contact member 92B to slide against and contact the discharge surface 24a, cleaning the entire surface of the discharge surface 24a (see FIG. 11). The second speed and the first speed may be the same.

[0083] In this sliding cleaning process, the second contact member 92B, which has a mesh-like fiber structure on its surface, can wipe and remove the thin film dirt 242 adhering to the ejection surface 24a. In this embodiment, by performing the contact cleaning process described above before the sliding cleaning process, the ejection surface 24a can be wiped in a state where liquid such as droplet dirt 241 on the ejection surface 24a has been removed, and therefore the thin film dirt 242 can be suitably wiped and removed.

[0084] Next, a series of cleaning process steps executed by the control unit 150 in the maintenance step will be described with reference to Fig. 12. Fig. 12 is a flowchart showing a series of cleaning process steps executed by the control unit 150 according to the embodiment.

[0085] In the maintenance process, first, the suction unit 110 performs a suction process on the droplet ejection head 24 (step S101). In the suction process, the valves of the functional liquid supply pipe 26b and the alcohol supply pipe 28b of the processing liquid supply unit 25 (FIG. 1) are closed, and only the valve of the solvent supply pipe 27b is opened to perform suction.

[0086] By this suction process, the ink filled in the droplet ejection head 24 is replaced with the solvent, and solid matter that is easily dissolved in the solvent and adheres to the inside of the ejection nozzle of the droplet ejection head 24 is dissolved and expelled from the ejection nozzle.

[0087] Next, the control unit 150 determines whether the dirt adhering to the discharge surface 24a of the droplet discharge head 24 is dry (step S102). For example, if the control unit 150 detects a discharge defect in the discharge nozzle of the droplet discharge head 24 in the above-mentioned discharge defect inspection, it may determine that the dirt on the discharge surface 24a, specifically the droplet dirt 241, is dry. Furthermore, the control unit 150 may determine whether the dirt adhering to the discharge surface 24a of the droplet discharge head 24 is dry by analyzing an image of the discharge surface 24a captured using, for example, the discharge inspection camera 31 (see FIG. 1) or a camera not shown.

[0088] In step S102, if it is determined that the dirt on the ejection surface 24a is dry (step S102, Yes), the first cleaning unit 90A performs a humidification process on the ejection surface 24a (step S103) before the contact cleaning process in step S104 described below.

[0089] By this humidification process, the droplet stains 241 that have dried and adhered to the ejection surface 24a are dissolved in the humidifying liquid, and the droplet stains 241 can be suitably absorbed and removed in the contact cleaning process in step S104 described later.

[0090] Subsequently, after completion of step S103, or if it is determined in step S102 that the dirt on the ejection surface 24a is not dry (step S102, No), the first cleaning unit 90A performs contact cleaning processing on the ejection surface 24a (step S104).

[0091] This contact cleaning process can suitably absorb and remove droplet stains 241 adhering to the ejection surface 24a. Furthermore, by removing the liquid adhering to the ejection surface 24a prior to the sliding cleaning process in step S106, which will be described later, it becomes easier to wipe and remove thin film stains 242 in the sliding cleaning process.

[0092] Subsequently, the ejection surface 24a is dried by the drying unit 120 (step S105). In the drying process, hot air is blown onto the ejection surface 24a of the droplet ejection head 24 to dry the ejection surface 24a.

[0093] This drying process dries the liquid contained inside the thin film dirt 242 adhering to the ejection surface 24a. This weakens the adhesive force of the thin film dirt 242 due to the surface tension of the liquid, making it easier to remove the thin film dirt 242 from the ejection surface 24a in the sliding cleaning process in step S106, which will be described later.

[0094] Subsequently, the second cleaning unit 90B performs a sliding cleaning process on the ejection surface 24a (step S106). By this contact cleaning process, the thin film dirt 242 adhering to the ejection surface 24a can be suitably wiped away and removed.

[0095] Finally, the control unit 150 determines whether the series of cleaning processes is satisfactory (step S107). In this determination, first, the control unit 150 controls the second imaging unit 130 to perform an imaging process of imaging the ejection surface 24a. Next, the control unit 150 analyzes the image captured by this imaging process to perform a determination process of whether or not the ejection surface 24a is soiled.

[0096] In this determination process, if no dirt is found on the ejection surface 24a (step S107, Yes), the control unit 150 ends the maintenance of the droplet ejection head 24. On the other hand, in this determination process, if dirt is found on the ejection surface 24a (step S107, No), the control unit 150 performs the processes of steps S101 to S107 again.

[0097] According to the droplet discharge device 1 of this embodiment, first, the droplet stains 241 adhering to the discharge surface 24a of the droplet discharge head 24 are removed by a contact cleaning process, and then the thin film stains 242 adhering to the discharge surface 24a are removed by a sliding cleaning process, so that even if the droplet stains 241 and the thin film stains 242 are adhering to the discharge surface 24a, the stains can be suitably removed. This makes it possible to reduce the time required to clean the discharge surface 24a compared to conventional techniques, and to efficiently clean the discharge surface 24a of the droplet discharge head 24.

[0098] Furthermore, according to the droplet ejection device 1 of this embodiment, the ejection surface 24a can be cleaned by reducing the number of contacts between the ejection surface 24a and the contact member compared to conventional technology, which reduces damage to the ejection nozzle of the droplet ejection head 24 and improves the lifespan of the droplet ejection head.

[0099] Up to this point, the embodiments of the present disclosure have been described. Below, modified examples of the embodiments of the present disclosure will be described.

[0100] (Modification of Drying Unit) In this embodiment, an example has been described in which the droplet discharge device 1 includes a drying unit 120 that dries the discharge surface 24a of the droplet discharge head 24, but the droplet discharge device 1 may also include a cooling unit that cools the discharge surface 24a instead of the drying unit 120. In such a case, the cooling unit is disposed between the first cleaning unit 90A and the second cleaning unit 90B along the Y-axis direction.

[0101] The cooling unit freezes the liquid contained inside the thin film dirt 242 adhering to the ejection surface 24a, for example, by spraying a cooling gas onto the ejection surface 24a. This weakens the adhesive force of the thin film dirt 242 due to the surface tension of the liquid, making it easier to remove the thin film dirt 242 from the ejection surface 24a in the sliding cleaning process in step S106.

[0102] (First Modified Example of Cleaning Unit) FIG. 13 shows a first modified example of the configuration of the cleaning unit according to the embodiment. In FIG. 13, a first cleaning unit 90A will be described as an example. The first cleaning unit 90A in this embodiment may be configured to include multiple contact rollers 91A. The multiple contact rollers 91A are arranged along the Y-axis direction. In this configuration, the multiple contact rollers 91A can be used to press the first contact member 92A into contact with the ejection surface 24a. This increases the contact area between the first contact member 92A and the ejection surface 24a during the contact cleaning process described above, thereby improving cleaning efficiency. Similarly, a configuration including multiple contact rollers 91B can be applied to the second cleaning unit 90B.

[0103] (Second Modification of Cleaning Unit) Fig. 14 shows a second modified example of the configuration of the cleaning unit according to the embodiment. In Fig. 14, a first cleaning unit 90A will be described as an example. As shown in Fig. 14, a cleaning substrate having first contact members 92A over the entire surface may be used as the first cleaning unit 90A. In this case, the cleaning substrate may be pressed into contact with the ejection surface 24a while the droplet ejection head 24 is stationary, thereby performing the contact cleaning process described above on the entire ejection surface 24a.

[0104] Similarly, a cleaning substrate having second contact members 92B over the entire surface may be used as the second cleaning unit 90B. In this case, the above-mentioned sliding cleaning process may be performed on the entire surface of the ejection surface 24a by pressing the cleaning substrate against the ejection surface 24a while moving the droplet ejection head 24 in the Y-axis direction.

[0105] (Other Variation 1) In this embodiment, an example has been described in which the first cleaning unit 90A humidifies the ejection surface 24a of the droplet ejection head 24. However, the maintenance unit 80 may be configured to include a separate cleaning unit (third cleaning unit) that humidifies the ejection surface 24a. The third cleaning unit has the same configuration as the first cleaning unit 90A. In such a case, the third cleaning unit may be disposed on the negative Y-axis side of the first cleaning unit 90A. In such a case, the aforementioned humidifying liquid supply unit 96 and humidifying liquid ejection nozzle may be provided to the third cleaning unit.

[0106] Furthermore, the maintenance unit 80 may be configured to include only one cleaning unit (fourth cleaning unit). In such a case, the fourth cleaning unit may be configured to be able to perform the aforementioned contact cleaning process using the first contact member 92A and the aforementioned sliding cleaning process using the second contact member 92B, in that order. In such a case, the fourth cleaning unit may be provided with the aforementioned humidifying liquid supply section 96 and a humidifying liquid discharge nozzle that supplies humidifying liquid to the first contact member 92A, thereby enabling the fourth cleaning unit to humidify the discharge surface 24a.

[0107] (Other Variation 2) In this embodiment, an example has been described in which the first contact member 92A is used to perform the contact cleaning process and the second contact member 92B is used to perform the sliding cleaning process, but these cleaning processes may be performed using the same type of contact member (third contact member). In such a case, the first cleaning unit 90A performs the contact cleaning process using the third contact member, and the second cleaning unit 90B performs the sliding cleaning process using the third contact member.

[0108] As described above, according to the embodiment of the present disclosure, the ejection surface of the droplet ejection head can be efficiently cleaned.

[0109] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0110] The present technology can also be configured as follows. (1) a droplet ejection head that ejects droplets of a functional liquid onto the surface of a workpiece; a cleaning unit that cleans the droplet ejection surface of the droplet ejection head; Control unit and Equipped with The cleaning unit comprises: a contact member that contacts the ejection surface; a sliding mechanism that slides the contact member against the ejection surface; Equipped with The control unit controls the cleaning unit to perform a contact cleaning process to clean the ejection surface by bringing the contact member into contact with the ejection surface without sliding it against the ejection surface, and a sliding cleaning process to clean the ejection surface by sliding the contact member against the ejection surface that has been cleaned by the contact cleaning process. (2) a moving mechanism for moving the droplet ejection head; The droplet ejection device according to (1), wherein the control unit controls the movement mechanism to move the droplet ejection head in the contact cleaning process, thereby bringing the contact member into contact with the entire surface of the ejection surface. (3) the contact member is an elongated member having a longitudinal direction in the first direction, The sliding mechanism advances the contact member in the first direction, The droplet ejection device described in (2) above, wherein the control unit controls the moving mechanism to move the droplet ejection head in the first direction during the contact cleaning process, while controlling the sliding mechanism to send the contact member in the first direction. (4) The droplet ejection device described in (3), wherein the control unit controls the moving mechanism to move the droplet ejection head in the first direction at a first speed during the contact cleaning process, while controlling the sliding mechanism to send the contact member in the first direction at the first speed. (5) The cleaning unit comprises: a first cleaning unit that performs the contact cleaning process; a second cleaning unit that performs the sliding cleaning process; The droplet ejection device according to any one of (1) to (4) above, comprising: (6) a moving mechanism for moving the droplet ejection head; The droplet ejection device described in (5) above, wherein the first cleaning unit and the second cleaning unit are arranged in the order of the first cleaning unit and the second cleaning unit along the movement direction of the droplet ejection head during the contact cleaning process. (7) The contact member is a first contact member included in the first cleaning unit; a second contact member provided in the first cleaning unit; Including, the second contact member is a member having a mesh-like surface, The droplet ejection device according to (5) or (6), wherein the first contact member is a member having higher liquid absorption than the second contact member. (8) a drying unit that dries the ejection surface; The droplet ejection device according to (6) or (7), wherein the drying unit is disposed between the first cleaning unit and the second cleaning unit. (9) a cooling unit that cools the ejection surface, The droplet ejection device according to (6) or (7), wherein the cooling unit is disposed between the first cleaning unit and the second cleaning unit. (10) The contact member is a first contact member included in the first cleaning unit; a second contact member provided in the first cleaning unit; Including, a moisturizing liquid supply unit that supplies moisturizing liquid to the ejection surface or the first contact member, The droplet ejection device described in any one of (5) to (9), wherein the control unit controls the moistening liquid supply unit to perform a moistening process to moisten the ejection surface before it is cleaned by the contact cleaning process. (11) an imaging unit for imaging the ejection surface, The control unit executes an imaging process of imaging the ejection surface cleaned by the contact cleaning process and the sliding cleaning process using the imaging unit, and a determination process of determining whether or not there is dirt on the ejection surface based on the image captured by the imaging process. (12) a droplet ejection head that ejects droplets of a functional liquid onto the surface of a workpiece; a cleaning unit including a contact member that comes into contact with the droplet ejection surface of the droplet ejection head, and a sliding mechanism that slides the contact member against the ejection surface; A method for cleaning a liquid ejection head in a droplet ejection device comprising: cleaning the ejection surface by using the cleaning unit to bring the contact member into contact with the ejection surface without sliding on the ejection surface; thereafter, cleaning the ejection surface by sliding the contact member against the ejection surface; A method for cleaning a droplet ejection head, comprising: (13) A computer-readable storage medium storing a program that runs on a computer and controls a droplet ejection device, A storage medium, wherein the program, when executed, causes a computer to control the droplet ejection device so as to perform the method for cleaning a droplet ejection head described in (12) above. [Explanation of symbols]

[0111] 1 Droplet discharge device 24 droplet ejection head 24a Discharge surface 90A First Cleaning Unit 90B Second cleaning unit 92A First contact member 92B second contact member 96 Humidifying liquid supply section 120 Drying Unit 130 Second imaging unit 150 control section double work

Claims

1. a droplet ejection head that ejects droplets of a functional liquid onto the surface of a workpiece; a cleaning unit that cleans the droplet ejection surface of the droplet ejection head; Control unit and Equipped with The cleaning unit comprises: a contact member that contacts the ejection surface; a sliding mechanism that slides the contact member against the ejection surface; Equipped with The control unit controls the cleaning unit to perform a contact cleaning process to clean the ejection surface by bringing the contact member into contact with the ejection surface without sliding it against the ejection surface, and a sliding cleaning process to clean the ejection surface by sliding the contact member against the ejection surface that has been cleaned by the contact cleaning process.

2. a moving mechanism for moving the droplet ejection head; The droplet ejection device according to claim 1 , wherein the control unit controls the movement mechanism to move the droplet ejection head in the contact cleaning process, thereby bringing the contact member into contact with the entire surface of the ejection surface.

3. the contact member is an elongated member having a longitudinal direction in the first direction, The sliding mechanism advances the contact member in the first direction, The droplet ejection device according to claim 2 , wherein the control unit controls the movement mechanism to move the droplet ejection head in the first direction, and controls the sliding mechanism to send out the contact member in the first direction, during the contact cleaning process.

4. The droplet ejection device according to claim 3, wherein the control unit controls the moving mechanism to move the droplet ejection head in the first direction at a first speed, while controlling the sliding mechanism to send the contact member in the first direction at the first speed, during the contact cleaning process.

5. The cleaning unit comprises: a first cleaning unit that performs the contact cleaning process; a second cleaning unit that performs the sliding cleaning process; The droplet ejection device of claim 1 , comprising:

6. a moving mechanism for moving the droplet ejection head; The droplet ejection device according to claim 5 , wherein the first cleaning unit and the second cleaning unit are arranged in this order along a direction in which the droplet ejection head moves during the contact cleaning process.

7. The contact member is a first contact member included in the first cleaning unit; a second contact member included in the first cleaning unit; Including, the second contact member is a member having a mesh-like surface, The droplet ejection device according to claim 5 , wherein the first contact member is a member having higher liquid absorption than the second contact member.

8. a drying unit that dries the ejection surface; The droplet ejection device according to claim 6 , wherein the drying unit is disposed between the first cleaning unit and the second cleaning unit.

9. a cooling unit that cools the ejection surface, The droplet ejection device according to claim 6 , wherein the cooling unit is disposed between the first cleaning unit and the second cleaning unit.

10. The contact member is a first contact member included in the first cleaning unit; a second contact member included in the first cleaning unit; Including, a moisturizing liquid supply unit that supplies moisturizing liquid to the ejection surface or the first contact member, The droplet ejection device according to claim 5 , wherein the control unit controls the moistening liquid supply unit to execute a moistening process for moistening the ejection surface before the ejection surface is cleaned by the contact cleaning process.

11. an imaging unit for imaging the ejection surface, The droplet ejection device according to claim 1, wherein the control unit performs an imaging process of imaging the ejection surface cleaned by the contact cleaning process and the sliding cleaning process using the imaging unit, and a determination process of determining whether or not there is dirt on the ejection surface based on the image captured by the imaging process.

12. a droplet ejection head that ejects droplets of a functional liquid onto the surface of a workpiece; a cleaning unit including a contact member that comes into contact with the droplet ejection surface of the droplet ejection head, and a sliding mechanism that slides the contact member against the ejection surface; A method for cleaning a liquid ejection head in a droplet ejection device comprising: cleaning the ejection surface by using the cleaning unit to bring the contact member into contact with the ejection surface without sliding on the ejection surface; thereafter, cleaning the ejection surface by sliding the contact member against the ejection surface; A method for cleaning a droplet ejection head, comprising:

13. A computer-readable storage medium storing a program that runs on a computer and controls a droplet ejection device, A storage medium, wherein the program, when executed, causes a computer to control the droplet ejection device so as to perform the method for cleaning a droplet ejection head according to claim 12.

Images