Head cleaning device, coating apparatus, and method for cleaning head

Abstract

A head cleaning device (150) includes: a liquid discharge head (1) including a nozzle (24) and a nozzle surface (250); a capping unit (700) including a channel member (703) that forms a first channel with the nozzle surface; a first supply unit (800) to supply a first cleaning solution to the first channel; and a control unit (417) to control the first supply unit to supply the first cleaning solution to the first channel, stop the supply of the first cleaning solution in a state where the nozzle surface is immersed in the first cleaning solution, supply the first cleaning solution again after a predetermined immersion time has elapsed after the supply of the first cleaning solution is stopped, and stop the supply of the first cleaning solution again.

Description

HEAD CLEANING DEVICE, COATING APPARATUS, AND METHOD FOR CLEANING HEAD[Technical Field]

[0001] The present disclosure relates to a head cleaning device, a coating apparatus, and a method for cleaning a head.[Background Art]

[0002] A head cleaning device and a head cleaning method for cleaning a nozzle and a nozzle surface of a liquid discharge head, and a coating apparatus including the head cleaning device are known.

[0003] A head cleaning device is disclosed that has a cleaning groove into which a nozzle surface can be inserted in order to clean a liquid discharge head, and supplies a cleaning solution to the cleaning groove in a state where the nozzle surface is inserted into the cleaning groove (see, for example, Patent Literature (PTL) 1).[Citation List][Patent Literature]

[0004] [PTL 1]Japanese Patent No. 5399053[Summary of Invention][Technical Problem]

[0005] However, in the device of Patent Literature (PTL) 1, there is room for improvement in cleanability of the liquid discharge head.An object of the present invention is to improve cleaning performance in head cleaning.[Solution to Problem]

[0006] A head cleaning device according to an embodiment of the present invention includes: a liquid discharge head including a nozzle and a nozzle surface; a capping unit including a channel member that forms a first channel with the nozzle surface; a first supply unit to supply a first cleaning solution to the first channel; and a control unit to control the first supply unit to supply the first cleaning solution to the first channel, stop the supply of the first cleaning solution in a state where the nozzle surface is immersed in the first cleaning solution, supply the first cleaning solution again after a predetermined immersion time has elapsedafter the supply of the first cleaning solution is stopped, and stop the supply of the first cleaning solution again.[Advantageous Effects of Invention]

[0007] According to embodiments of the present invention, cleaning performance can be improved in head cleaning.[Brief Description of Drawings]

[0008] A more complete appreciation of embodiments of the present disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings.[FIG. 1]FIG. 1 is a diagram illustrating an overall configuration of a coating apparatus according to an embodiment of the present invention.[FIG. 2]FIG. 2 is a diagram illustrating a configuration of a liquid supply unit included in a coating apparatus according to an embodiment of the present invention.[FIG. 3]FIG. 3 is a perspective view of a liquid discharge head included in a coating apparatus according to an embodiment of the present invention.[FIG. 4]FIG. 4 is a cross-sectional view of a liquid discharge head including a plurality of nozzles included in a coating apparatus according to an embodiment of the present invention. [FIG. 5A]FIG. 5A is a block diagram illustrating a hardware configuration of a coating apparatus according to an embodiment of the present invention.[FIG. 5B]FIG. 5B is a block diagram illustrating a functional configuration of a controller included in a coating apparatus according to an embodiment of the present invention.[FIG. 6]FIG. 6 is a first diagram illustrating a configuration of a head cleaning device according to a first embodiment of the present invention.[FIG. 7]FIG. 7 is a second diagram illustrating a configuration of the head cleaning device according to the first embodiment of the present invention.[FIG. 8]FIG. 8 is a first diagram illustrating a configuration of a capping unit included in the head cleaning device according to the first embodiment of the present invention.[FIG. 9]FIG. 9 is a second diagram illustrating the configuration of the capping unit included in the head cleaning device according to the first embodiment of the present invention. [FIG. 10A]FIG. 10A is a first diagram illustrating a cleaning operation by the head cleaning device according to the first embodiment of the present invention.[FIG. 10B]FIG. 10B is a second diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. [FIG. IOC]FIG. IOC is a third diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention.[FIG. 10D]FIG. 10D is a fourth diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention.[FIG. 10E]FIG. 10E is a fifth diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. [FIG. 10F]FIG. 10F is a sixth diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. [FIG. 10G]FIG. 10G is a seventh diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention.[FIG. 10H]FIG. 10H is an eighth diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention.[FIG. 101]FIG. 101 is a ninth diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention.[FIG. 11]FIG. 11 is a flowchart illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention.[FIG. 12A]FIG. 12A is a first diagram illustrating a cleaning operation by a head cleaning device according to a first modification.[FIG. 12B]FIG. 12B is a second diagram illustrating the cleaning operation by the head cleaning device according to the first modification.[FIG. 12C]FIG. 12C is a third diagram illustrating the cleaning operation by the head cleaning device according to the first modification.[FIG. 12D]FIG. 12D is a fourth diagram illustrating the cleaning operation by the head cleaning device according to the first modification.[FIG. 12E]FIG. 12E is a fifth diagram illustrating the cleaning operation by the head cleaning device according to the first modification.[FIG. 12F]FIG. 12F is a sixth diagram illustrating the cleaning operation by the head cleaning device according to the first modification.[FIG. 12G]FIG. 12G is a seventh diagram illustrating the cleaning operation by the head cleaning device according to the first modification.[FIG. 12H]FIG. 12H is an eighth diagram illustrating the cleaning operation by the head cleaning device according to the first modification.[FIG. 121]FIG. 121 is a ninth diagram illustrating the cleaning operation by the head cleaning device according to the first modification.[FIG. 13 A]FIG. 13 A is a first diagram illustrating a cleaning operation by a head cleaning device according to a second modification.[FIG. 13B]FIG. 13B is a second diagram illustrating the cleaning operation by the head cleaning device according to the second modification.[FIG. 13C]FIG. 13C is a third diagram illustrating the cleaning operation by the head cleaning device according to the second modification.[FIG. 13D]FIG. 13D is a fourth diagram illustrating the cleaning operation by the head cleaning device according to the second modification.[FIG. 13E]FIG. 13E is a fifth diagram illustrating the cleaning operation by the head cleaning device according to the second modification.[FIG. 13F]FIG. 13F is a sixth diagram illustrating the cleaning operation by the head cleaning device according to the second modification.[FIG. 13G]FIG. 13G is a seventh diagram illustrating the cleaning operation by the head cleaning device according to the second modification.[FIG. 13H]FIG. 13H is an eighth diagram illustrating the cleaning operation by the head cleaning device according to the second modification.[FIG. 131]FIG. 131 is a ninth diagram illustrating the cleaning operation by the head cleaning device according to the second modification.[FIG. 14]FIG. 14 is a flowchart illustrating a cleaning operation by a head cleaning device according to a third modification.[FIG. 15]FIG. 15 is a flowchart illustrating a cleaning operation by a head cleaning device according to a fourth modification.[FIG. 16]FIG. 16 is a diagram illustrating a configuration of a head cleaning device according to a second embodiment of the present invention.[FIG. 17A]FIG. 17A is a first diagram illustrating a cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 17B]FIG. 17B is a second diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 17C]FIG. 17C is a third diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 17D]FIG. 17D is a fourth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 17E]FIG. 17E is a fifth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 17F]FIG. 17F is a sixth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 17G]FIG. 17G is a seventh diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 17H]FIG. 17H is an eighth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 171]FIG. 171 is a ninth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 18]FIG. 18 is a flowchart illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention.[FIG. 19]FIG. 19 is a diagram illustrating a channel member of a head cleaning device according to a third embodiment of the present invention.[FIG. 20]FIG. 20 is a diagram illustrating a channel member of a head cleaning device according to a fourth embodiment of the present invention.[FIG. 21]FIG. 21 is a block diagram illustrating a functional configuration of a control unit included in a head cleaning device according to a fifth embodiment of the present invention. [FIG. 22]FIG. 22 is a diagram illustrating a scanning system of a liquid discharge head in a coating apparatus according to a sixth embodiment of the present invention.The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views.[Description of Embodiments]

[0009] In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.Referring now to the drawings, embodiments of the present disclosure are described below. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.A head cleaning device, a coating apparatus, and a method for cleaning a head according to embodiments of the present invention will be described in detail with reference to the drawings. However, the following embodiments illustrate a head cleaning device, a coating apparatus, and a method for cleaning a head for embodying the technical idea of embodiments of the present invention, and are not limited to the following.

[0010] In addition, unless otherwise specified, dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments of the present invention are not intended to limit the scope of the embodiments of the present invention only thereto, and are merely illustrative examples. For example, the size and positional relationship of the components illustrated in the drawings may be exaggerated for clarity of description. Note that, in the following description, like names and like reference signs denote like or equivalent components, and a detailed description thereof may be omitted as appropriate.

[0011] EmbodimentsOverall Configuration of Coating ApparatusFirst, an overall configuration of a coating apparatus according to an embodiment of the present invention will be described with reference to FIG. 1.

[0012] Here, as an example of the coating apparatus, a coating apparatus 100 that applies a liquid to a vehicle body of an automobile that is an object 200 to coat the vehicle body is illustrated. The object 200 may be a body of an automobile, a body of an aircraft, a hull of a ship, or other three-dimensional structures.

[0013] As illustrated in FIG. 1, a coating apparatus 100 according to the present embodiment includes four coating robots 2.

[0014] Each coating robot 2 includes a base portion 10 installed on a floor surface or the like, a first arm 11 provided to the base portion 10, a second arm 12 connected to the first arm 11, and a head unit 13 provided at a distal end of the second arm 12. The first arm 11 and the second arm 12 of the coating robot 2 are robot arms rotatably and swingably connected via joint portions, and function as a moving mechanism that moves the head unit 13 to a desired position by rotational driving or swing driving. The moving mechanism that moves the head unit 13 may be a linear actuator or the like that linearly moves the head unit 13 in one direction, two directions orthogonal to each other, or three directions, in addition to the robot arms.

[0015] Specifically, the first arm 11 is provided to the base portion 10 to be rotatable in a direction of an arrow A in FIG. 1 and to be swingable in a direction of an arrow B. The second arm 12 is provided at a distal end of the first arm 11 to be rotatable in a direction of an arrow C in FIG. 1 and to be swingable in a direction of an arrow D. The head unit 13 is attached to the distal end of the second arm 12 so as to be rotatable in a direction of an arrow E in FIG. 1 and swingable in a direction of an arrow F. The number of coating robots 2 is not limited to four, and may be one, two, three, or five or more.

[0016] The head unit 13 includes a liquid discharge head 1 and a position detection unit 3 that detects a position of the object 200. The liquid discharge head 1 includes a nozzle and a nozzle surface, and can discharge liquid from the nozzle. The position detection unit 3 is attached to the distal end of the second arm 12 integrally with the liquid discharge head 1. The position detection unit 3 includes, for example, a stereo camera or the like that detects three-dimensional position information of three or more feature points of the object 200. The stereo camera includes a plurality of cameras. The position detection unit 3 acquires a distance image of the object 200 by a triangulation method on the basis of parallax between images captured by the cameras.

[0017] The coating apparatus 100 according to the present embodiment includes a liquid supply unit 4, a maintenance recovery unit 40, and a control unit 5 in addition to the coating robot 2.

[0018] The liquid supply unit 4 includes a liquid reservoir 6 and an air supply unit 7. The liquid reservoir 6 is, for example, a tank that stores liquid 8 such as a coating material therein. The air supply unit 7 is a compressor or the like that supplies air into the liquid reservoir 6. When air is supplied from the air supply unit 7 to the liquid reservoir 6, an inside of the liquid reservoir 6 is pressurized, so that the liquid 8 in the liquid reservoir 6 is supplied to the liquid discharge head 1 and discharged as droplets from the nozzle of the liquid discharge head 1. The liquid discharge head 1 can also discharge liquid in a thread-like manner in addition to liquid droplets. Although only a path for supplying the liquid 8 from the liquid reservoir 6 to one liquid discharge head 1 is illustrated in FIG. 1, the liquid 8 is supplied from the liquid reservoir 6 to all liquid discharge heads 1 in the same manner. A plurality of liquid reservoirs 6 that store different colors or types of liquids may be prepared, and a color or type of liquid may be switched and supplied to each liquid discharge head 1.

[0019] The maintenance recovery unit 40 includes a capping unit 700 (illustrated in FIG. 5A) for maintaining and recovering a function of the liquid discharge head 1. The maintenance recovery unit 40 is provided for each of the coating robots 2. In a case where the next coating is not performed for a while after coating, or in a case where the coating is performed by switching the liquid to a different color or type, the maintenance recovery unit 40 performs a maintenance and recovery operation after completion of the previous coating. Specifically, the nozzle surface of the liquid discharge head 1 is capped, and residual liquid adhering to the liquid discharge head 1 is washed away by a cleaning solution. Thus, clogging of the nozzle due to drying of the residual liquid can be prevented, and adhesion of the residual liquid to the object when the liquid is switched and applied can be prevented.

[0020] The control unit 5 controls an operation of each coating robot 2 and a discharge operation of each liquid discharge head 1 on the basis of position information of the object 200 detected by the position detection unit 3 in addition to shape data of the object 200, image data of coating, and the like input in advance. Thus, the head unit 13 is moved along a shape of the object 200, and the liquid is applied from the liquid discharge head 1 to the surface of the object 200. The control unit 5 also controls an operation of the maintenance recovery unit 40. Further, the control unit 5 controls supply of a first cleaning solution. In FIG. 1, only signal lines from the control unit 5 for one coating robot 2, one liquid discharge head 1, and one maintenance recovery unit 40 and a signal line from one position detection unit 3 to the control unit 5 are illustrated, but the control unit 5 controls operations of all coating robots 2, all the liquid discharge heads 1, and all the maintenance recovery units 40, and receives detection signals from all the position detection units 3.

[0021] FIG. 2 is a diagram illustrating a more specific configuration of the liquid supply unit 4 included in the coating apparatus 100 according to the present embodiment.

[0022] As illustrated in FIG. 2, the liquid supply unit 4 includes a plurality of air regulators 9 in addition to the liquid reservoirs 6 and the air supply unit 7. The air regulators 9 are provided to an air channel 111 connecting the air supply unit 7 and the plurality of liquid reservoirs 6. The air regulators 9 adjust air pressures sent from the air supply unit 7 to the respective liquid reservoirs 6. The liquid reservoirs 6 are individually connected to the liquid discharge heads 1 via air channels 112, respectively. Thus, when the inside of each liquid reservoir 6 is pressurized, the liquid 8 is supplied from each liquid reservoir 6 to each liquid discharge head 1. Instead of being provided for each liquid discharge head 1, the liquid reservoir 6 may be one liquid reservoir provided in common for all the liquid discharge heads 1.

[0023] Configuration of Liquid Discharge Head 1Next, a configuration of the liquid discharge head 1 included in the coating apparatus 100 according to the present embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a perspective view of the liquid discharge head 1 included in the coating apparatus 100 according to the present embodiment. FIG. 4 is a cross-sectional view of the liquid discharge head 1 including a plurality of nozzles 24, included in the coating apparatus 100 according to the present embodiment.

[0024] As illustrated in FIG. 4, the liquid discharge head 1 includes nozzles 24 that discharges liquid, and a nozzle surface 250 on which nozzle holes of the nozzle 24 are arranged. As illustrated in FIGS. 3 and 4, the liquid discharge head 1 includes a housing 20, and a supply port 21 and a collection port 22 provided to the housing 20.

[0025] As illustrated in FIG. 4, a plurality of discharge modules 23 is arranged in a row or in a plurality of rows in the housing 20. Each discharge module 23 includes a nozzle plate 25, a nozzle valve 26, a piezoelectric element 27, and a liquid channel 28. In the nozzle plate 25, each discharge module 23 is provided with the nozzle 24 for discharging liquid. The nozzle plate 25 has the nozzle surface 250 on a side opposite to a side on which the nozzle valve 26 is located. The nozzle 24 is openable and closable by the nozzle valve 26. The piezoelectric element 27 is a drive unit that expands and contracts when a voltage is applied to open and close the nozzle valve 26. The liquid channels 28 communicate with each other among the discharge modules 23 to configure a common channel. The liquid channels 28 also communicate with the supply port 21 and the collection port 22.

[0026] In a state where the valve of the collection port 22 is closed, when liquid is supplied from the supply port 21 into the housing 20, the liquid flows into the liquid channel 28 and is pressurized. At this time, when no voltage is applied to the piezoelectric element 27, the nozzle 24 is closed by the nozzle valve 26, and thus no liquid is discharged from the nozzle 24. On the other hand, when a voltage is applied to the piezoelectric element 27, the nozzle valve 26 is driven, and the nozzle 24 is opened, to thereby discharge liquid from the nozzle 24. The liquid that has not been discharged from the nozzle 24 is discharged to the outside through the collection port 22.

[0027] Hardware Configuration of Coating Apparatus 100FIG. 5A is a block diagram illustrating a hardware configuration of the coating apparatus 100 according to the present embodiment.

[0028] As illustrated in FIG. 5A, the coating apparatus 100 includes an input device 700A, a computer 300, a controller 400, a head control device 500, and a robot control device 600 in addition to the plurality of coating robots 2. Here, two coating robots 2 are displayed, and the remaining coating robots 2 are omitted.

[0029] Each of the coating robots 2 includes an encoder sensor 16 and a robot drive unit 17. The encoder sensor 16 is an optical sensor or the like that optically detects a slit of an encoder provided to a connection portion between the base portion 10 and the first arm 11, a connection portion between the first arm 11 and the second arm 12, and a connection portion between the second arm 12 and the head unit 13 of the coating robot 2. A rotation amount and a swing amount of each of the first arm 11, the second arm 12, and the head unit 13 can be grasped by detection of the encoder sensor 16, and thus three-dimensional position information of the head unit 13 can be acquired. The robot drive unit 17 is a driving unit that performs a rotating operation and a swinging operation of the first arm 11, the second arm 12, and the head unit 13.

[0030] The input device 700A is a device to which information regarding the shape data of the object 200, image data of coating, coordinate data, a coating mode, a coating range (coating start position and coating end position), a coating instruction, and the like is input. The input device 700A includes a keyboard, a mouse, a touch panel, and the like for a user or the like to perform an input operation. Various pieces of information input in the input device 700A are transmitted to the computer 300.

[0031] The computer 300 includes a raster image processor (RIP) unit 301 that performs image processing on image data received from the input device 700A, and a rendering unit 302 that decomposes the image data into coating data for each scan of the head unit 13. In addition, the computer 300 receives the shape data of the object 200 from the input device 700A, acquires actual position information of the object 200 detected by the position detection unit 3, and generates a coating route of the coating robot 2 on the basis of the shape data and the actual position information of the object 200. In addition, the computer 300 calculates an incident angle a of droplets with respect to the object 200 in the generated coating route. The incident angle a is calculated by using any one of the shape data of the object 200 received from the input device 700A, the position information of the object 200 detected by the position detection unit 3, and the three-dimensional position information of the head unit 13 detected by the encoder sensor 16, or a plurality of pieces of these pieces of information.

[0032] The controller 400, the head control device 500, and the robot control device 600 function as the control unit 5 illustrated in FIG. 1 that controls an operation of each coating robot 2 and the discharge operation of each liquid discharge head 1. In this case, one head control device 500 and one robot control device 600 are provided, but the head control device 500 and the robot control device 600 may be individually provided for each coating robot 2.

[0033] The controller 400 receives coating data and a command signal from the computer 300 and controls the entire operation of the coating apparatus 100.

[0034] The controller 400 includes a central processing unit (CPU) 401, a read only memory (ROM) 402, a random access memory (RAM) 403, a hard disk drive / solid state drive (HDD / SSD) 404, and an interface (VF) 405.These are communicably connected to each other via a system bus S.

[0035] The CPU 401 executes control processing including various types of arithmetic processing. The ROM 402 stores a program used for driving the CPU 401, such as an initial program loader (IPL). The RAM 403 is used as a work area of the CPU 401. The HDD / SSD 404 stores various types of information such as programs, captured images acquired by thestereo camera, detection information by various sensors such as the encoder sensor 16, and the like.

[0036] The I / F 405 is an interface for connecting the controller 400 to various external devices. Here, the external devices are the head control device 500, the robot control device 600, a first supply unit 800, a second supply unit 820, and the like.

[0037] At least a part of the functions implemented by the CPU 401 may be implemented by an electric circuit or an electronic circuit.

[0038] The head control device 500 receives a control signal and a discharge cycle signal from the controller 400, and controls a discharge amount and a discharge timing of the liquid discharge head 1 on the basis of the received control signal and discharge cycle signal. At this time, by controlling the discharge amount and the discharge timing of the liquid discharge head 1 on the basis of the incident angle a, the amount of droplets to be discharged and the landing interval Px in the moving direction X are controlled to the amount of droplets and the landing interval according to the incident angle a.

[0039] The robot control device 600 receives a control signal from the controller 400, and controls driving of the robot drive unit 17 on the basis of a received synchronization control signal. At this time, the robot drive unit 17 is controlled on the basis of the incident angle a, whereby an inclination P of a nozzle row of the liquid discharge head 1 is controlled, and a landing interval Py in a movement orthogonal direction Y is controlled to a landing interval according to the incident angle a.

[0040] The capping unit 700 includes a first channel serving as a channel of the first cleaning solution. The capping unit 700 can form a sealed space by coming in contact with the liquid discharge head 1. More specifically, the capping unit 700 has an upper surface (i.e., surface facing the nozzle surface 250) that is opened, and an opening thereof comes into contact with the nozzle surface 250 at the time of cleaning to form a sealed space including the nozzle surface 250. From another point of view, the capping unit 700 can seal the nozzle surface 250 of the liquid discharge head 1 by making contact with the nozzle surface 250. The first supply unit 800 supplies the first cleaning solution for cleaning the nozzle surface 250 illustrated in FIG. 4 to the capping unit 700 forming the sealed space. The second supply unit 820 supplies a second cleaning solution for cleaning the liquid channel 28 of the liquid discharge head 1 to the liquid discharge head 1.

[0041] Functional Configuration of Controller 400FIG. 5B is a block diagram illustrating a functional configuration of the controller 400 included in the coating apparatus according to the present embodiment. The description will be given with reference to FIG. 5A as appropriate.

[0042] The controller 400 includes a system control unit 411, a nozzle valve drive control unit 412, a discharge cycle signal generation unit 413, a memory control unit 414, a data storage unit 415, a robot control signal generation unit 416, a first supply control unit 417, and a second supply control unit 418.

[0043] Each function of the system control unit 411, the nozzle valve drive control unit 412, the discharge cycle signal generation unit 413, the memory control unit 414, and the robot control signal generation unit 416 is implemented by a processor such as the CPU 401 executing processing defined in a program stored in a nonvolatile memory such as the ROM 402. The function of the data storage unit 415 is implemented by a nonvolatile memory such as the HDD / SSD 404.

[0044] The system control unit 411 receives coating data and a command signal from the computer 300 and controls the entire operation of the coating system 1000. The system control unit 411 may further include the functions of the RIP unit 301 and the rendering unit 302 included in the computer 300.

[0045] The nozzle valve drive control unit 412 generates a control signal for controlling the opening / closing drive of the nozzle valve 26 on the basis of the coating data and the incident angle a received from the computer 300. The discharge cycle signal generation unit 413 generates a discharge cycle signal of the liquid discharge head 1 on the basis of an output signal from the encoder sensor 16, coating data received from the computer 300, and the incident angle a. The memory control unit 414 controls the data storage unit 415. The data storage unit 415 stores coating data, coating range data, and the like received from the computer 300. The robot control signal generation unit 416 generates a synchronization control signal for matching the drive of each coating robot 2 with a droplet discharge operation on the basis of the coating data and the information regarding the coating route from the computer 300. The robot control signal generation unit 416 generates a control signal for determining the inclination P of the nozzle row of the liquid discharge head 1 on the basis of the incident angle a calculated by the computer 300. The first supply control unit 417 controls supply of the first cleaning solution by the first supply unit 800. The second supply control unit 418 controls supply of the second cleaning solution by the second supply unit 820.

[0046] First EmbodimentConfiguration Example of Head Cleaning Device According to First EmbodimentNext, a head cleaning device according to a first embodiment of the present invention included in the coating apparatus 100 will be described with reference to FIGS. 6 to 9.

[0047] FIG. 6 is a first diagram illustrating a configuration of a head cleaning device 150 according to the first embodiment of the present invention. FIG. 7 is a second diagram illustrating a configuration of the head cleaning device 150 according to the first embodiment of the present invention. FIG. 6 illustrates the head cleaning device 150 in which the liquid discharge head 1 is disposed so that the liquid discharge head 1 can discharge liquid in a direction indicated by an arrow G10. FIG. 7 illustrates the head cleaning device 150 in which the liquid discharge head 1 is disposed so that the liquid discharge head 1 can discharge liquid in a direction indicated by an arrow G20 orthogonal to the direction indicated by the arrow G10 in FIG. 6.

[0048] FIG. 8 is a first diagram illustrating a configuration of the capping unit 700 included in the head cleaning device 150 according to the first embodiment of the present invention. FIG. 9 is a second diagram illustrating a configuration of the capping unit 700 included in the head cleaning device 150 according to the first embodiment of the present invention. FIG. 9 illustrates a cross section of the head cleaning device 150 including a plurality of nozzles 24 included in the head cleaning device 150.

[0049] As illustrated in FIGS. 6 to 9, the head cleaning device 150 includes the liquid discharge head 1 including nozzles 24 and the nozzle surface 250, the capping unit 700 including a first channel 703 serving as a channel of the first cleaning solution, and the control unit 5 that controls supply of the first cleaning solution. The control unit 5 performs control to supply the first cleaning solution to the first channel 703, stop the supply of the first cleaning solution in a state where the nozzle surface 250 is immersed, supply the first cleaning solution again after a predetermined immersion time has elapsed after the supply of the first cleaning solution is stopped, and then stop the supply of the first cleaning solution. In the example illustrated in FIGS. 6 to 9, the head cleaning device 150 includes the liquid discharge head 1 including the nozzles 24 that discharge liquid and the nozzle surface 250 on which nozzle holes 240 of the nozzles 24 are arranged. The head cleaning device 150 further includes the capping unit 700 that can form a sealed space in contact with the liquid discharge head 1, the first supply unit 800 that supplies the first cleaning solution for cleaning at least one of the nozzles 24 and the nozzle surface 250 to the capping unit 700 forming the sealed space, and the control unit 5 that controls supply of the first cleaning solution by the first supply unit 800. The capping unit 700 includes a channel member 702 that is disposed to face the nozzle surface 250 in the sealed space and forms the first channel 703 of the first cleaning solution. The control unit 5 can perform control to supply the first cleaning solution to the first channel 703 of the first cleaning solution, stop the supply of the first cleaning solution in a state where the nozzle surface 250 is immersed, supply the first cleaning solution again aftera predetermined immersion time has elapsed after the supply of the first cleaning solution is stopped, and then stop the supply of the first cleaning solution.

[0050] Conventionally, in order to clean a nozzle and a nozzle surface of a liquid discharge head, various cleaning methods such as a method of wiping the nozzle and the nozzle surface with a wiping blade, an absorbent member, or the like and a method of spraying a cleaning solution or air to the nozzle and the nozzle surface are used in a head cleaning device. However, in the conventional cleaning method, in at least one of a case where the nozzle has a complicated shape and a case where a high- viscosity liquid is used as the coating liquid, the coating liquid remains in the nozzle and the nozzle surface, and the cleaning property may be deteriorated. In particular, in a method of controlling discharge of liquid by opening and closing a nozzle hole by a nozzle valve (for example, a valve jet method), a surface layer of the nozzle has a narrowed shape, and high viscosity liquid is discharged, so that the cleanability tends to be low.

[0051] In the first embodiment of the present invention, the first channel 703 is formed by the channel member 702 included in the capping unit 700 and the nozzle surface 250, and the first cleaning solution is caused to flow into the first channel 703, so that each of the nozzle holes 240 and the nozzle surface 250 can be immersed with the first cleaning solution. At this time, the coating liquid flowing out or eluted from the inside of the liquid discharge head 1 and the first cleaning solution are mixed. If immersion is continued in a mixed state, outflow or elution of the coating liquid from the inside of the liquid discharge head 1 is less likely to be promoted, and cleaning performance may not be improved. For example, when a cross- sectional area of the first channel 703 in the direction orthogonal to the direction in which the first cleaning solution flows is narrowed in order to increase fluid resistance of the first channel 703, the amount of the first cleaning solution flowing through the first channel 703 is reduced, and the outflow or elution of the coating liquid from the inside of the liquid discharge head 1 is less likely to be promoted.

[0052] In the first embodiment of the present invention, the head cleaning device 150 controls the control unit 5 to supply the first cleaning solution to the first channel 703, stop the supply of the first cleaning solution in a state where the nozzle surface 250 is immersed, supply the first cleaning solution again after a predetermined immersion time has elapsed after the supply of the first cleaning solution is stopped, and then stop the supply of the first cleaning solution. Accordingly, by refreshing the first cleaning solution in the first channel 703, it is possible to promote the outflow or elution of the coating liquid from the inside of the liquid discharge head 1 that has become less likely to be promoted, and enhance the cleaning property by the head cleaning device 150. As described above, according to the first embodiment of the present invention, it is possible to provide the head cleaning device 150 that can improve the cleaning performance.

[0053] In the head cleaning device 150, in the channel member 702, a surface facing the nozzle surface 250 has a substantially planar shape. Thus, the narrow first channel 703 through which the first cleaning solution can flow can be formed between the channel member 702 and the nozzle surface 250, and the nozzle surface 250 can be cleaned with the first cleaning solution. In the present specification, the substantially flat surface means a surface that allows the interval between the channel member 702 and the nozzle surface 250 to have a deviation of 1 / 10 or less in contrast to the ideal flat surface.

[0054] In the head cleaning device 150, the liquid discharge head 1 includes the nozzle valve 26 as a valve body that opens and closes the nozzle hole 240, and the piezoelectric element 27 as a drive means that opens and closes the nozzle valve 26. When the sealed space is formed, the piezoelectric element 27 drives the nozzle valve 26 to open and close. Accordingly, the head cleaning device 150 can control the supply of the first cleaning solution to the first channel 703.

[0055] In the example illustrated in FIGS. 6 to 9, the capping unit 700 includes a rubber member 701. The capping unit 700 can form a sealed space by the rubber member 701 coming into contact with the nozzle surface 250 of the liquid discharge head 1. The channel member 702 is disposed inside the rubber member 701. When the capping unit 700 forms the sealed space, the channel member faces the nozzle surface 250 in the sealed space, and as illustrated in FIG. 9, the first channel 703 can be formed between the channel member and the nozzle surface 250. In FIGS. 6 to 9, for the purpose of illustrating that the capping unit 700 includes the rubber member 701 and the channel member 702, the reference signs of the capping unit 700 and the rubber member 701 are written together, and the reference signs of the capping unit 700 and the channel member 702 are written together. Hereinafter, reference numerals may also be used for the same purpose.

[0056] In the example illustrated in FIGS. 6 to 9, the head cleaning device 150 includes a movable plate 710 on which the capping unit 700 is placed, a plurality of springs 721 that moves the movable plate 710 by applying a biasing force to the movable plate 710, and a substrate 720 facing the movable plate 710 with the plurality of springs 721 interposed therebetween. The movable plate 710, the plurality of springs 721, and the substrate 720 constitute a maintenance recovery unit 40 in FIG. 1. The movable plate 710 is movable in a direction of an arrow G30 illustrated in FIG. 8, and can move the capping unit 700.

[0057] In the example illustrated in FIGS. 6 and 7, the head cleaning device 150 includes a first cleaning solution tank 910 that stores the first cleaning solution, a first compressor 920 that can supply air to the capping unit 700, and a first switching valve 930 that switches the supply of the first cleaning solution or air to the capping unit 700. The head cleaning device150 further includes a supply port 730 through which one of the first cleaning solution or the air is supplied to the capping unit 700, and a discharge port 740 through which one of the first cleaning solution or the air is discharged from the capping unit 700. The head cleaning device 150 further includes a first waste liquid tank 940 that stores waste liquid of the first cleaning solution discharged from the capping unit 700, and a second switching valve 950 that switches flow or non-flow from the capping unit 700 to the first waste liquid tank 940. Furthermore, the head cleaning device 150 includes a coating liquid tank 810 that stores a coating liquid to be supplied to the liquid discharge head 1, and the liquid supply unit 4 that supplies the liquid stored in the coating liquid tank 810 to the liquid discharge head 1. In the example illustrated in FIGS. 6 and 7, the head cleaning device 150 does not include the second supply unit 820, but the head cleaning device 150 may include the second supply unit 820.

[0058] As the first supply unit 800, an air pressurizing tank, a pump, or the like can be used. In the example illustrated in FIGS. 6 and 7, the first supply unit 800 supplies the first cleaning solution stored in the first cleaning solution tank 910 to the first channel 703 in the capping unit 700 through a first supply pipe 911. In the example illustrated in FIG. 6, the first cleaning solution is fed in the first supply pipe 911 in a direction of an arrow Gil, and is supplied to the first channel 703 of the capping unit 700 through the supply port 730. In the example illustrated in FIG. 7, the first cleaning solution is fed in the first supply pipe 911 in a direction of an arrow G21, and is supplied to the first channel 703 of the capping unit 700 through the supply port 730.

[0059] As the first switching valve 930 and the second switching valve 950, an electromagnetic valve or the like can be used. When ending the head cleaning operation, the head cleaning device 150 stops the driving of the first supply unit 800 and stops the supply of the first cleaning solution from the first cleaning solution tank 910. Then, by driving the first compressor 920 to send air, the first cleaning solution in the first channel 703 of the capping unit 700 is discharged to the first waste liquid tank 940 through a first discharge pipe 941. In the example illustrated in FIG. 6, the first cleaning solution discharged from the capping unit 700 through the discharge port 740 is fed in a direction of an arrow G12 in the first discharge pipe 941 and discharged to the first waste liquid tank 940. In the example illustrated in FIG. 7, the first cleaning solution discharged from the capping unit 700 through the discharge port 740 is fed in a direction of an arrow G22 in the first discharge pipe 941 and discharged to the first waste liquid tank 940.

[0060] When the nozzle surface 250 of the liquid discharge head 1 is cleaned by the head cleaning device 150, there is no particular restriction on the posture of the liquid discharge head 1. For example, the nozzle surface 250 of the liquid discharge head 1 can be cleaned by the head cleaning device 150 even when the liquid discharge head 1 is in a posture in whichdischarging in the direction of the arrow GIO is possible as illustrated in FIG. 6 or in a posture in which discharging in the direction orthogonal to the arrow GIO is possible. In the posture illustrated in FIG. 7, when the supply of the first cleaning solution to the capping unit 700 is stopped, the hydraulic head differential relationship may be adjusted or the valve body need not be provided so that the first channel 703 is filled with the first cleaning solution as it is.

[0061] The component of the first cleaning solution is selected depending on a coating liquid, and one having excellent solubility is preferred. In general, pure water is used for a dye-based aqueous coating material, and thinner or the like is used for a solvent coating material. However, in practice, individual evaluation of the compatibility of the first cleaning solution may be performed for each type of coating material.

[0062] Operation Example of Head Cleaning Device 150Next, an operation of the head cleaning device 150 will be described with reference to FIGS. 10A to 101.FIG. 10A is a first diagram illustrating a cleaning operation by the head cleaning device according to the first embodiment of the present invention. FIG. 10B is a second diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. FIG. 10C is a third diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. FIG. 10D is a fourth diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. FIG. 10E is a fifth diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. FIG. 10F is a sixth diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. FIG. 10G is a seventh diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. FIG. 10H is an eighth diagram illustrating a cleaning operation by the head cleaning device according to the first embodiment of the present invention. FIG. 101 is a ninth diagram illustrating the cleaning operation by the head cleaning device according to the first embodiment of the present invention. FIGS. 10A to 101 are enlarged views of the first channel 703, the nozzle 24, and the nozzle valve 26 in the cross-sectional view of the liquid discharge head 1 illustrated in FIG. 9.

[0063] In a state where the nozzle surface 250 of the liquid discharge head 1 is sealed by the capping unit 700, the first cleaning solution flows through the first channel 703, whereby dirt such as a coating liquid adhering to the nozzle surface 250 is easily cleaned. On the other hand, since the first cleaning solution is less likely to flow into the nozzle 24 of the liquid discharge head 1, the cleaning property in the nozzle 24 may not be improved.

[0064] The head cleaning device 150 first seals the liquid discharge head 1 with the capping unit 700, and fills the first channel 703 with the first cleaning solution. Thereafter, the state in which the first channel 703 is filled with the first cleaning solution is maintained for a predetermined immersion time. Thus, the coating liquid in the nozzle 24 flows out or is eluted to the outside of the nozzle 24 by a fluid diffusion action. The head cleaning device 150 can clean the inside of the nozzle 24 by the coating liquid in the nozzle 24 flowing out or eluting to the outside of the nozzle 24. Hereinafter, the cleaning operation by the head cleaning device 150 will be specifically described with reference to FIGS. 10A to 101. The description will be given with reference to FIGS. 6 to 9 as appropriate.

[0065] First, as illustrated in FIG. 10A, the head cleaning device 150 lowers the liquid discharge head 1 toward the channel member 702 (direction of an arrow G40).

[0066] Subsequently, the head cleaning device 150 brings the liquid discharge head 1 into contact with the rubber member 701 of the capping unit 700. Thus, as illustrated in FIG. 10B, a sealed space is formed between the liquid discharge head 1 and the capping unit 700, and the first channel 703 is formed in the sealed space by the nozzle surface 250 and the channel member 702.

[0067] Subsequently, the head cleaning device 150 supplies a first cleaning solution 80 from the first cleaning solution tank 910 to the first channel 703 by the first supply unit 800. As illustrated in FIG. 10C, when the first channel 703 is filled inside with the first cleaning solution 80, in other words, when the nozzle surface 250 is immersed in the first cleaning solution 80, the head cleaning device 150 stops the supply of the first cleaning solution 80.

[0068] Subsequently, the head cleaning device 150 stands by for a predetermined immersion time T in a state where the supply of the first cleaning solution is stopped. During this time, as illustrated in FIG. 10D, the coating liquid 8 in the nozzle 24 flows out or elutes into the first channel 703 by a fluid diffusion action. Arrows G41 indicate directions in which the coating liquid 8 flows out or eluted.

[0069] Subsequently, as illustrated in FIG. 10E, when the coating liquid flows out or elutes into the first channel 703, the first cleaning solution 80 in the first channel 703 is mixed with the coating liquid 8. A portion 81 indicates a portion where the first cleaning solution 80 and the coating liquid 8 are mixed. Even if immersion is continued in such a mixed state, the outflow or elution of the coating liquid 8 into the first channel 703 is less likely to be promoted. One reason for this is that the cross-sectional area of the first channel 703 in the direction orthogonal to the direction in which the first cleaning solution 80 flows (direction of an arrow G42) is narrow, and thus the amount of the first cleaning solution 80 flowing through the first channel 703 is small. Accordingly, when it is necessary to continue to causethe coating liquid 8 in the nozzle 24 to flow out or elute, the head cleaning device 150 starts the supply of the first cleaning solution 80 to the first channel 703 again. Thus, the first cleaning solution 80 is supplied from the first cleaning solution tank 910 illustrated in FIG. 6 to the first channel 703, and flows in the first channel 703 in the direction of the arrow G42, so that the first cleaning solution 80 in the first channel 703 is refreshed. When the first cleaning solution 80 in the first channel 703 is refreshed, the head cleaning device 150 stops the supply of the first cleaning solution 80.

[0070] With reference to FIG. 10F, a case where it is necessary that the head cleaning device 150 continues to cause the coating liquid 8 in the nozzle 24 to flow out or elute will be described. The head cleaning device 150 stands by for a predetermined immersion time T in a state where the supply of the first cleaning solution 80 is stopped after the first cleaning solution 80 is supplied again to the first channel 703. Meanwhile, as illustrated in FIG. 10F, the coating liquid 8 in the nozzle 24 flows out or elutes into the first channel 703 due to the fluid diffusion effect. Arrows G43 indicate directions in which the coating liquid 8 flows out or eluted.

[0071] Subsequently, the head cleaning device 150 supplies the first cleaning solution 80 from the first cleaning solution tank 910 to the first channel 703. Thus, as illustrated in FIG. 10G, the first cleaning solution 80 in the first channel 703 is refreshed. An arrow G44 indicates a direction in which the first cleaning solution 80 flows through the first channel 703.

[0072] Subsequently, the head cleaning device 150 drives the first compressor 920 illustrated in FIG. 6 to supply air 90 into the first channel 703 in order to prevent the first cleaning solution 80 remaining in the capping unit 700 from leaking when the capping unit 700 is opened after the cleaning is finished.Thus, as illustrated in FIG. 10H, the first cleaning solution 80 in the first channel 703 is discharged.An arrow G45 indicates a direction in which the first cleaning solution 80 is discharged from the first channel 703.

[0073] By the above procedure, as illustrated in FIG. 101, the coating liquid 8 and the first cleaning solution 80 inside each of the nozzle 24 and the first channel 703 are discharged, and the air 90 exists.Thus, the head cleaning device 150 can clean at least one of the nozzle 24 and the nozzle surface 250 of the liquid discharge head 1.

[0074] In the example illustrated in FIGS. 10A to 101, the channel member 702 between the liquid discharge head 1 and the capping unit 700 is a narrow channel having a narrow cross-sectional area of the first channel 703 in the direction orthogonal to the direction in which the first cleaning solution 80 flows. Thus, by increasing the fluid resistance to the wall surface of the first channel 703, the cleaning property of the wall surface of the first channel 703 can be improved, and the amount of the first cleaning solution 80 used can be reduced.

[0075] Next, FIG. 11 is a flowchart illustrating a cleaning operation by the head cleaning device 150 according to the first embodiment of the present invention. The head cleaning device 150 starts the operation of FIG. 11, for example, when receiving an operation input to start cleaning from an operation unit or the like of the coating apparatus 100 illustrated in FIG. 1.

[0076] First, in step Si l, the head cleaning device 150 moves the liquid discharge head 1 to bring the liquid discharge head 1 into contact with the capping unit 700. Thus, the nozzle surface 250 of the liquid discharge head 1 is sealed, and a sealed space is formed by the capping unit 700 (see FIGS. 10A and 10B).

[0077] Subsequently, in step S12, the head cleaning device 150 supplies the first cleaning solution 80 to the first channel 703 by the first supply unit 800 (see FIG. 10C). Thereafter, the head cleaning device 150 continues the supply of the first cleaning solution 80 by the first supply unit 800 until the supply of the first cleaning solution 80 is stopped.

[0078] Subsequently, in step S13, the head cleaning device 150 determines whether or not the filling of the first cleaning solution 80 into the first channel 703 has been completed (whether the nozzle surface 250 has been immersed in the first cleaning solution 80).

[0079] If it is determined in step S13 that the filling has not been completed (step S13, NO), the head cleaning device 150 performs the operation of step S13 again. On the other hand, when it is determined that the filling has been completed (step S13, YES), the head cleaning device 150 stops the supply of the first cleaning solution 80 to the first channel 703 by the first supply unit 800 in step S14 (see FIG. 10D).

[0080] Subsequently, in step S15, the head cleaning device 150 measures the elapsed time from the stop of the supply of the first cleaning solution 80, and determines whether or not the elapsed time has passed a predetermined first immersion time T.

[0081] If it is determined in step S 15 that it has not passed the time (step S 15, NO), the head cleaning device 150 performs the operation of step S15 again. On the other hand, when it is determined that it has passed the time (step S15, YES), the head cleaning device 150 determines whether or not to supply the first cleaning solution 80 to the first channel 703again in order to cause the coating liquid in the nozzle 24 to flow out or elute in step S16 (see FIG. 10E).

[0082] In step S16, when it is determined to supply the first cleaning solution 80 (step S16, YES), the head cleaning device 150 performs the operations in and after step S12 again. On the other hand, when it is determined not to supply the first cleaning solution 80 (step S16, NO), the head cleaning device 150 supplies the first cleaning solution 80 to the first channel 703 by the first supply unit 800 for refreshing in step S17. Thereafter, the head cleaning device 150 continues the supply of the first cleaning solution 80 by the first supply unit 800 until the supply of the first cleaning solution 80 is stopped.

[0083] Subsequently, in step S18, the head cleaning device 150 causes the first supply unit 800 to stop the supply of the first cleaning solution 80 to the first channel 703. The timing at which the supply of the first cleaning solution 80 is stopped is preferably the timing at which the first cleaning solution 80 in the first channel 703 is refreshed. The supply of the first cleaning solution 80 may be stopped in accordance with a determination result as to whether a predetermined refresh time has elapsed, or in accordance with a detection result by a sensor provided in the first channel 703 as to whether a predetermined concentration has been reached.

[0084] Subsequently, in step S19, the head cleaning device 150 causes the first compressor 920 to supply the air 90 to the first channel 703 to cause the first cleaning solution 80 in the first channel 703 to be discharged (see FIG. 10H).

[0085] Subsequently, in step S20, the head cleaning device 150 opens the capping unit 700. The capping unit 700 may be performed by an operator of the head cleaning device 150.

[0086] As described above, the head cleaning device 150 can clean at least one of the nozzle 24 and the nozzle surface 250 of the liquid discharge head 1.

[0087] Modification of Cleaning OperationHereinafter, various modifications of the cleaning operation by the head cleaning device 150 will be described. Note that the same names and reference numerals as those of the embodiments of the present invention described above indicate the same or similar members or configurations, and detailed description thereof will be omitted as appropriate. The same applies to the following modifications and embodiments of the present invention.

[0088] First ModificationFirst, a first modification will be described. The present modification is mainly different from the first embodiment of the present invention in that the control unit 5 causesthe liquid discharge head 1 to discharge liquid in a state where the nozzle surface 250 is immersed in the first cleaning solution 80.

[0089] For example, when the nozzle hole 240 of the nozzle 24 is blocked by the thickened coating liquid 8 or the like, the first cleaning solution 80 may not enter the nozzle 24 as it is. In the head cleaning device 150 according to the present modification, the control unit 5 drives the nozzle valve 26 to open the nozzle hole 240, and causes a predetermined amount of the coating liquid 8 in the nozzle 24 to be discharged to the first channel 703 between the liquid discharge head 1 and the capping unit 700. Thus, the thickened coating liquid 8 that closes the nozzle hole 240 is removed, and the first cleaning solution 80 can enter the nozzle 24. As a result, in the present modification, the cleaning performance of the head cleaning device 150 can be improved. Hereinafter, the cleaning operation according to the first modification will be specifically described with reference to FIGS. 12A to 121. Note that the drawings overlapping with FIGS. 10A to 101 described above will be omitted as appropriate.

[0090] FIG. 12A is a first diagram illustrating a cleaning operation by the head cleaning device 150 according to the first modification. FIG. 12B is a second diagram illustrating the cleaning operation by the head cleaning device according to the first modification. FIG. 12C is a third diagram illustrating the cleaning operation by the head cleaning device according to the first modification. FIG. 12D is a fourth diagram illustrating the cleaning operation by the head cleaning device according to the first modification. FIG. 12E is a fifth diagram illustrating the cleaning operation by the head cleaning device according to the first modification. FIG. 12F is a sixth diagram illustrating the cleaning operation by the head cleaning device according to the first modification. FIG. 12G is a seventh diagram illustrating the cleaning operation by the head cleaning device according to the first modification. FIG. 12H is an eighth diagram illustrating the cleaning operation by the head cleaning device according to the first modification. FIG. 121 is a ninth diagram illustrating the cleaning operation by the head cleaning device according to the first modification. FIGS. 12A to 121 are enlarged views of the first channel 703, the nozzle 24, and the nozzle valve 26 in the cross-sectional view of the liquid discharge head 1 illustrated in FIG. 9. The description will be given with reference to FIGS. 6 to 9 as appropriate.

[0091] First, the head cleaning device 150 lowers the liquid discharge head 1 toward the channel member 702.

[0092] Subsequently, the head cleaning device 150 brings the liquid discharge head 1 into contact with the rubber member 701 of the capping unit 700. Thus, a sealed space is formed between the liquid discharge head 1 and the capping unit 700, and the first channel 703 is formed in the sealed space by the nozzle surface 250 and the channel member 702.

[0093] Subsequently, the head cleaning device 150 supplies the first cleaning solution 80 from the first cleaning solution tank 910 to the first channel 703 by the first supply unit 800. As illustrated in FIG. 12A, when the first channel 703 is filled inside with the first cleaning solution 80, in other words, when the nozzle surface 250 is immersed in the first cleaning solution 80, the head cleaning device 150 stops the supply of the first cleaning solution 80.

[0094] When the first cleaning solution 80 is filled in the first channel 703, as illustrated in FIG. 12B, the nozzle hole 240 may be blocked with a thickened coating liquid (referred to as a thickened liquid 8a), and the first cleaning solution 80 may not enter the nozzle 24.

[0095] The head cleaning device 150 drives the nozzle valve 26 so that the first cleaning solution 80 can enter the nozzle 24, and moves the nozzle valve 26 in the direction of an arrow G50 as illustrated in FIG. 12C. Since the liquid channel 28 is filled with the coating liquid 8 in a pressurized state, the coating liquid 8 passes through the nozzle 24 by the movement of the nozzle valve 26 and is discharged from the nozzle hole 240.Arrows G51 indicate directions in which the coating liquid 8 flows into the nozzle 24 in accordance with the movement of the nozzle valve 26. By this discharge operation, the liquid 8 in the nozzle 24 is discharged, and the thickened liquid 8a closing the nozzle hole 240 is discharged. Thus, the first cleaning solution 80 can enter the nozzle 24.

[0096] Subsequently, the head cleaning device 150 stands by for a predetermined immersion time T in a state where the supply of the first cleaning solution is stopped. During this time, since the thickened liquid 8a that has blocked the nozzle hole 240 is removed and the nozzle hole 240 is opened, the coating liquid 8 in the nozzle 24 flows out or elutes out to the first channel 703 by a fluid diffusion action as illustrated in FIG. 12D. Arrows G52 indicate directions in which the coating liquid 8 flows out or elutes.

[0097] Subsequently, when the coating liquid flows out or elutes into the first channel 703, the first cleaning solution 80 in the first channel 703 is mixed with the coating liquid 8 as illustrated in FIG. 12E. The portion 81 indicates a portion where the first cleaning solution 80 and the coating liquid 8 are mixed. Even if the immersion is continued in this mixed state, the outflow or elution of the coating liquid 8 into the first channel 703 is less likely to be promoted. One reason for this is that the cross-sectional area of the first channel 703 in the direction orthogonal to the direction in which the first cleaning solution 80 flows (direction of an arrow G53) is narrow, and thus the amount of the first cleaning solution 80 flowing through the first channel 703 is small. Accordingly, when it is necessary to continue to cause the coating liquid 8 in the nozzle 24 to flow out or elute, the head cleaning device 150 starts the supply of the first cleaning solution 80 to the first channel 703 again. Thus, the first cleaning solution 80 is supplied from the first cleaning solution tank 910 illustrated in FIG. 6 to the first channel 703, and flows in the first channel 703 in the direction of the arrow G53,so that the first cleaning solution 80 in the first channel 703 is refreshed. When the first cleaning solution 80 in the first channel 703 is refreshed, the head cleaning device 150 stops the supply of the first cleaning solution 80.

[0098] With reference to FIG. 12F, a case where it is necessary that the head cleaning device 150 continues to cause the coating liquid 8 in the nozzle 24 to flow out or elute will be described. The head cleaning device 150 stands by for a predetermined immersion time T in a state where the supply of the first cleaning solution 80 is stopped after the first cleaning solution 80 is supplied again to the first channel 703. During this time, as illustrated in FIG. 12F, the coating liquid 8 in the nozzle 24 flows out or elutes into the first channel 703 due to the fluid diffusion effect. Arrows G54 indicate directions in which the coating liquid 8 flows out or eluted.

[0099] Subsequently, the head cleaning device 150 supplies the first cleaning solution 80 from the first cleaning solution tank 910 to the first channel 703. Thus, as illustrated in FIG. 12G, the first cleaning solution 80 in the first channel 703 is refreshed. An arrow G55 indicates a direction in which the first cleaning solution 80 flows through the first channel 703.

[0100] Subsequently, the head cleaning device 150 stands by for a predetermined immersion time T in a state where the supply of the first cleaning solution 80 is stopped. During this time, as illustrated in FIG. 12H, the coating liquid 8 in the nozzle 24 flows out or elutes into the first channel 703 due to the fluid diffusion effect. Arrows G56 indicate directions in which the coating liquid 8 flows out or eluted.

[0101] Subsequently, as illustrated in FIG. 121, the first cleaning solution 80 is supplied from the first cleaning solution tank 910 to the first channel 703, and the first cleaning solution 80 in the first channel 703 is refreshed. An arrow G57 indicates a direction in which the first cleaning solution 80 flows in the first channel 703.

[0102] As described above, the head cleaning device 150 can perform the head cleaning operation according to the second modification.

[0103] Second ModificationNext, a second modification will be described. The present modification is mainly different from the first embodiment of the present invention in that the control unit 5 causes the liquid discharge head 1 to discharge liquid in a state where the nozzle surface 250 is immersed in the first cleaning solution 80.

[0104] For example, when the surface layer of the nozzle hole 240 is dried and an air layer 8b is formed, the first cleaning solution 80 may not enter the inside of the nozzle 24 as it is. In the head cleaning device 150 according to the present modification, the control unit 5 drives the nozzle valve 26 to open the nozzle hole 240, and causes a predetermined amount of the coating liquid 8 in the nozzle 24 to be discharged to the first channel 703 between the liquid discharge head 1 and the capping unit 700. Thus, the air layer 8b closing the nozzle hole 240 is removed, and the first cleaning solution 80 can enter the nozzle 24. As a result, in the present modification, the cleaning performance of the head cleaning device 150 can be improved. Hereinafter, the cleaning operation according to the second modification will be specifically described with reference to FIGS. 13A to 131. Note that the drawings overlapping with FIGS. 10A to 101 described above will be omitted as appropriate.

[0105] FIG. 13 A is a first diagram illustrating a cleaning operation by the head cleaning device 150 according to the second modification. FIG. 13B is a second diagram illustrating the cleaning operation by the head cleaning device according to the second modification. FIG. 13C is a third diagram illustrating the cleaning operation by the head cleaning device according to the second modification. FIG. 13D is a fourth diagram illustrating the cleaning operation by the head cleaning device according to the second modification. FIG. 13E is a fifth diagram illustrating the cleaning operation by the head cleaning device according to the second modification. FIG. 13F is a sixth diagram illustrating the cleaning operation by the head cleaning device according to the second modification. FIG. 13G is a seventh diagram illustrating the cleaning operation by the head cleaning device according to the second modification. FIG. 13H is an eighth diagram illustrating the cleaning operation by the head cleaning device according to the second modification. FIG. 131 is a ninth diagram illustrating the cleaning operation by the head cleaning device according to the second modification. FIGS. 13 A to 131 are enlarged views of the first channel 703, the nozzle 24, and the nozzle valve 26 in the cross-sectional view of the liquid discharge head 1 illustrated in FIG. 9. The description will be given with reference to FIGS. 6 to 9 as appropriate.

[0106] First, the head cleaning device 150 lowers the liquid discharge head 1 toward the channel member 702.

[0107] Subsequently, the head cleaning device 150 brings the liquid discharge head 1 into contact with the rubber member 701 of the capping unit 700. Thus, a sealed space is formed between the liquid discharge head 1 and the capping unit 700, and the first channel 703 is formed in the sealed space by the nozzle surface 250 and the channel member 702.

[0108] Subsequently, the head cleaning device 150 supplies the first cleaning solution 80 from the first cleaning solution tank 910 to the first channel 703 by the first supply unit 800. As illustrated in FIG. 13A, when the first channel 703 is filled inside with the first cleaningsolution 80, in other words, when the nozzle surface 250 is immersed in the first cleaning solution 80, the head cleaning device 150 stops the supply of the first cleaning solution 80.

[0109] When the first cleaning solution 80 is filled in the first channel 703, as illustrated in FIG. 13B, the nozzle hole 240 may be blocked by the air layer 8b, and the first cleaning solution 80 may not enter the nozzle 24.

[0110] The head cleaning device 150 drives the nozzle valve 26 so that the first cleaning solution 80 can enter the nozzle 24, and moves the nozzle valve 26 in the direction of an arrow G60 as illustrated in FIG. 13C. Since the liquid channel 28 is filled with the coating liquid 8 in a pressurized state, the coating liquid 8 passes through the nozzle 24 by the movement of the nozzle valve 26 and is discharged from the nozzle hole 240.Arrows G61 indicate directions in which the coating liquid 8 flows into the nozzle 24 by the movement of the nozzle valve 26. With this discharge operation, the liquid 8 in the nozzle 24 is discharged, and the air layer 8b closing the nozzle hole 240 is discharged. Thus, the first cleaning solution 80 can enter the nozzle 24.

[0111] Subsequently, the head cleaning device 150 stands by for a predetermined immersion time T in a state where the supply of the first cleaning solution is stopped. During this time, since the air layer 8b closing the nozzle hole 240 is removed and the nozzle hole 240 is opened, as illustrated in FIG. 13D, the coating liquid 8 in the nozzle 24 flows out or elutes into the first channel 703 by the fluid diffusion action. Arrows G62 indicate directions in which the coating liquid 8 flows out or eluted.

[0112] Subsequently, as illustrated in FIG. 13E, when the coating liquid flows out or elutes into the first channel 703, the first cleaning solution 80 in the first channel 703 is mixed with the coating liquid 8. The portion 81 indicates a portion where the first cleaning solution 80 and the coating liquid 8 are mixed. Even if the immersion is continued in this mixed state, the outflow or elution of the coating liquid 8 into the first channel 703 is less likely to be promoted. One reason for this is that the cross-sectional area of the first channel 703 in the direction orthogonal to the direction in which the first cleaning solution 80 flows (direction of an arrow G63) is narrow, and thus the amount of the first cleaning solution 80 flowing through the first channel 703 is small. Accordingly, when it is necessary to continue to cause the coating liquid 8 in the nozzle 24 to flow out or elute, the head cleaning device 150 starts the supply of the first cleaning solution 80 to the first channel 703 again. Thus, the first cleaning solution 80 is supplied from the first cleaning solution tank 910 illustrated in FIG. 6 to the first channel 703, and flows in the first channel 703 in the direction of the arrow G63, so that the first cleaning solution 80 in the first channel 703 is refreshed. When the first cleaning solution 80 in the first channel 703 is refreshed, the head cleaning device 150 stops the supply of the first cleaning solution 80.

[0113] With reference to FIG. 13F, a case where it is necessary that the head cleaning device 150 continues to cause the coating liquid 8 in the nozzle 24 to flow out or elute will be described. The head cleaning device 150 stands by for a predetermined immersion time T in a state where the supply of the first cleaning solution 80 is stopped after the first cleaning solution 80 is supplied again to the first channel 703. During this time, as illustrated in FIG. 13F, the coating liquid 8 in the nozzle 24 flows out or elutes into the first channel 703 due to the fluid diffusion effect. Arrows G64 indicate directions in which the coating liquid 8 flows out or eluted.

[0114] Subsequently, the head cleaning device 150 supplies the first cleaning solution 80 from the first cleaning solution tank 910 to the first channel 703. Thus, as illustrated in FIG. 13G, the first cleaning solution 80 in the first channel 703 is refreshed. An arrow G65 indicates a direction in which the first cleaning solution 80 flows through the first channel 703.

[0115] Subsequently, the head cleaning device 150 stands by for a predetermined immersion time T in a state where the supply of the first cleaning solution 80 is stopped. During this time, as illustrated in FIG. 13H, the coating liquid 8 in the nozzle 24 flows out or elutes into the first channel 703 due to the fluid diffusion effect. Arrows G66 indicate directions in which the coating liquid 8 flows out or eluted.

[0116] Subsequently, as illustrated in FIG. 131, the first cleaning solution 80 is supplied from the first cleaning solution tank 910 to the first channel 703, and the first cleaning solution 80 in the first channel 703 is refreshed. An arrow G67 indicates a direction in which the first cleaning solution 80 flows in the first channel 703.

[0117] As described above, the head cleaning device 150 can perform the head cleaning operation according to the second modification.

[0118] Third ModificationNext, a third modification will be described. The present modification is mainly different from the first embodiment of the present invention in that the head cleaning device 150 further includes a vibration applying unit that applies vibration to the first cleaning solution 80 flowing through the first channel 703.

[0119] The function of the vibration applying unit is implemented by, for example, the control unit 5. By controlling the operation of the first supply unit 800, the vibration applying unit can periodically vary the flow rate of the first cleaning solution 80 supplied to the capping unit 700 and apply vibration associated with a change in the flow rate to the firstcleaning solution 80. However, the vibration applying unit is not limited to the above. For example, the function of the vibration applying unit may be implemented by a piezo actuator. The vibration applying unit can apply vibration to the first cleaning solution 80 flowing through the first channel 703 by bringing the piezo actuator into contact with the first supply pipe 911 and vibrating the first supply pipe 911 by expansion and contraction of the piezo actuator according to an applied voltage.

[0120] FIG. 14 is a flowchart illustrating a cleaning operation by the head cleaning device 150 according to the third modification. Note that description of operations similar to the operations described with reference to FIG. 11 will be omitted as appropriate, and differences from FIG. 11 will be mainly described.

[0121] After the supply of the first cleaning solution 80 is stopped in step S24, the head cleaning device 150 causes the vibration applying unit to apply vibration to the first cleaning solution 80 flowing through the first channel 703 in step S25. Thereafter, the head cleaning device 150 continues applying vibration to the first cleaning solution 80 by the vibration applying unit until the application of vibration is stopped. By applying vibration to the first cleaning solution 80, the coating liquid 8 flowing out or eluted in the vicinity of the nozzle hole 240 can be diffused, and the solubility can be prevented from being lowered. As a result, in the present modification, the cleaning performance by the head cleaning device 150 can be improved. In this modification, the apparent holding time of the first cleaning solution 80 may be shortened. Note that the vibration applying unit may continue to apply vibration for a predetermined time, or may periodically or aperiodically repeat application and stop of vibration.

[0122] In step S27, the head cleaning device 150 determines whether or not to supply the first cleaning solution 80 to the first channel 703 again in order to keep the coating liquid in the nozzle 24 flowing out or eluting.

[0123] In step S27, when it is determined to supply the first cleaning solution 80 (step S27, YES), the head cleaning device 150 stops the application of vibration by the vibration applying unit in step S28. Thereafter, the operations in and after step S22 are performed again. On the other hand, when it is determined not to supply the first cleaning solution 80 (step S27, NO), the head cleaning device 150 stops the application of vibration by the vibration applying unit in order to end the head cleaning operation in step S29. Thereafter, in step S30, the first cleaning solution 80 is supplied to the first channel 703 for refreshing.

[0124] The head cleaning device 150 can perform the cleaning operation according to the third modification by the procedure illustrated in FIG. 14.

[0125] Fourth ModificationNext, a fourth modification will be described. The present modification is mainly different from the first modification and the second modification in that the nozzle valve 26 is opened to cause the liquid discharge head 1 to discharge liquid in order to remove the thickened liquid 8a and the air layer 8b described above, the nozzle valve 26 is opened after the first cleaning solution 80 is filled for the first time, and the nozzle valve 26 is closed after the second filling of the first cleaning solution 80.

[0126] FIG. 15 is a flowchart illustrating a cleaning operation by the head cleaning device 150 according to the fourth modification. Note that description of operations similar to the operations described with reference to FIG. 11 will be omitted as appropriate, and differences from FIG. 11 will be mainly described.

[0127] In step S45, the head cleaning device 150 determines whether or not to open and close the nozzle valve 26.

[0128] If it is determined in step S45 that opening and closing are not to be performed (step545, NO), the head cleaning device 150 performs the operation of step S45 again. On the other hand, when it is determined to perform opening and closing (step S45, YES), the head cleaning device 150 executes the opening and closing operation of the nozzle valve 26 in step546. For example, the head cleaning device 150 opens the nozzle valve 26.

[0129] In step S48, the head cleaning device 150 determines whether or not to supply the first cleaning solution 80 to the first channel 703 again in order to cause the coating liquid in the nozzle 24 to flow out or elute.

[0130] In step S48, when it is determined to supply the first cleaning solution 80 (step S48, YES), the head cleaning device 150 closes the nozzle valve 26 in step S49. Thereafter, the operations in and after step S42 are performed again. On the other hand, when it is determined not to supply the first cleaning solution 80 (step S48, NO), the head cleaning device 150 closes the nozzle valve 26 in order to end the head cleaning operation in step S50. Thereafter, in step S51, the first cleaning solution 80 is supplied to the first channel 703 for refreshing.

[0131] The head cleaning device 150 can perform the cleaning operation according to the fourth modification by the procedure illustrated in FIG. 15.

[0132] Second EmbodimentConfiguration Example of Head Cleaning Device According to Second EmbodimentNext, a head cleaning device according to a second embodiment of the present invention included in the coating apparatus 100 will be described with reference to FIG. 16. FIG. 16 is a diagram illustrating a configuration of a head cleaning device 150a according to the second embodiment of the present invention.

[0133] In the second embodiment of the present invention, the head cleaning device 150a includes a second supply unit 820 that supplies a second cleaning solution for cleaning the liquid channel 28 of the liquid discharge head 1 to the liquid discharge head 1. Here, the liquid channel 28 is an example of a second channel. The control unit 5 supplies the second cleaning solution to the liquid discharge head 1 by the second supply unit 820 to clean the liquid discharge head 1, and then supplies the first cleaning solution 80 to the first channel 703 of the capping unit 700 by the first supply unit 800. The present embodiment is mainly different from the first embodiment in the above points.

[0134] In the second embodiment of the present invention, by supplying the second cleaning solution to the liquid channel 28 of the liquid discharge head 1 by the second supply unit 820, the liquid channel 28 of the liquid discharge head 1 can be further cleaned in addition to at least one of the nozzle 24 and the nozzle surface 250 of the liquid discharge head 1.

[0135] In the example illustrated in FIG. 16, the coating apparatus 100 includes a second cleaning solution tank 830 that stores a second cleaning solution. The head cleaning device 150a includes a second compressor 840 that can supply air to the liquid discharge head 1, and a third switching valve 850 that switches the supply of the second cleaning solution or the air to the capping unit 700. The head cleaning device 150a further includes a fourth switching valve 860 that switches supply of a coating liquid or a second cleaning solution to the liquid discharge head 1. The head cleaning device 150a further includes a second waste liquid tank 870 that stores waste liquid of the second cleaning solution discharged from the capping unit 700, and a fifth switching valve 880 that switches between flow and non-flow from the capping unit 700 to the second waste liquid tank 870. The above point is mainly different from FIG. 6.

[0136] In the second embodiment of the present invention, the head cleaning device 150a switches the fourth switching valve 860 when coating an object. Thus, the coating liquid 8 can be supplied from the coating liquid tank 810 to the liquid discharge head 1, and the supply of the second cleaning solution from the second cleaning solution tank 830 to the liquid discharge head 1 through a second supply pipe 831 is blocked. The liquid supplied from the coating liquid tank 810 is supplied to the supply port 21 (see FIG. 4). A second discharge pipe 871 leading to the second waste liquid tank 870 in FIG. 16 is connected to the collection port 22 (see FIG. 4) of the liquid discharge head 1.

[0137] On the other hand, the head cleaning device 150a switches the fourth switching valve 860 when cleaning the liquid channel 28 in the liquid discharge head 1. Thus, the supply of liquid from the coating liquid tank 810 to the liquid discharge head 1 is stopped, and the second cleaning solution can be supplied from the second cleaning solution tank 830 to the liquid discharge head 1 through the second supply pipe 831. In the head cleaning device 150a, the coating liquid tank 810 to be supplied to the liquid discharge head 1 may be provided for each of a plurality of colors, and the fourth switching valve 860 provided for each of the plurality of colors may be switched. In this manner, the coating apparatus 100 can change the color to be coated. When the color to be applied is changed, the head cleaning device 150a stops the supply of liquid from the coating liquid tank 810 to the liquid discharge head 1, and enables the supply of the second cleaning solution from the second cleaning solution tank 830 to the liquid discharge head 1. The head cleaning device 150a can supply a coating liquid from a coating liquid tank of another color to the liquid discharge head 1 after cleaning the liquid discharge head 1 with the second cleaning solution.

[0138] In the example illustrated in FIG. 16, the second cleaning solution tank 830 for supplying the second cleaning solution to the liquid discharge head 1 and the first cleaning solution tank 910 for supplying the first cleaning solution to the capping unit 700 are separately provided. However, the embodiment is not limited to this configuration, the first cleaning solution and the second cleaning solution may be the same, and the cleaning solution tank may be shared. The cleaning solution may be supplied by branching from a common cleaning solution tank into the liquid discharge head 1 and the capping unit 700.

[0139] Operation Example of Head Cleaning Device 150aFIG. 17A is a first diagram illustrating a cleaning operation by the head cleaning device according to the second embodiment of the present invention. FIG. 17B is a second diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention. FIG. 17C is a third diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention. FIG. 17D is a fourth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention. FIG. 17E is a fifth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention. FIG. 17F is a sixth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention. FIG. 17G is a seventh diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention. FIG. 17H is an eighth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention. FIG. 171 is a ninth diagram illustrating the cleaning operation by the head cleaning device according to the second embodiment of the present invention. FIGS. 17 A to 171 are enlarged views of the first channel 703, the nozzle24, and the nozzle valve 26 in the cross-sectional view of the liquid discharge head 1 illustrated in FIG. 9. The description will be given with reference to FIGS. 9 and 16 as appropriate.

[0140] First, as illustrated in FIG. 17A, the head cleaning device 150a lowers the liquid discharge head 1 toward the channel member 702 (direction of an arrow G70). In the nozzle hole 240 illustrated in FIG. 17A, the thickened liquid 8a that blocks the nozzle hole 240 is generated.

[0141] Subsequently, the head cleaning device 150a brings the liquid discharge head 1 into contact with the rubber member 701 of the capping unit 700. Thus, as illustrated in FIG. 17B, a sealed space is formed between the liquid discharge head 1 and the capping unit 700, and the first channel 703 is formed in the sealed space by the nozzle surface 250 and the channel member 702.

[0142] Subsequently, as illustrated in FIG. 17C, the head cleaning device 150a causes the second supply unit 820 to start supplying the second cleaning solution 82 from the second cleaning solution tank 830 to the liquid channel 28, and continues the supply. An arrow G71 indicates a direction in which the second cleaning solution 82 flows in the liquid channel 28.When the second cleaning solution 82 is supplied, the coating liquid 8 and the second cleaning solution 82 are discharged to the second waste liquid tank 870 located downstream of the liquid discharge head 1.

[0143] Subsequently, the head cleaning device 150a supplies the first cleaning solution 80 from the first cleaning solution tank 910 to the first channel 703 by the first supply unit 800. As illustrated in FIG. 17D, when the first channel 703 is filled inside with the first cleaning solution 80, in other words, when the nozzle surface 250 is immersed in the first cleaning solution 80, the head cleaning device 150a stops the supply of the first cleaning solution 80. During this time, the supply of the second cleaning solution 82 to the liquid channel 28 is continued.

[0144] Subsequently, the head cleaning device 150a stands by for a predetermined immersion time T in a state where the supply of the first cleaning solution is stopped. During this time, as illustrated in FIG. 17E, the coating liquid 8 in the nozzle 24 flows out or elutes into the first channel 703 by the fluid diffusion action. During this time, the supply of the second cleaning solution 82 to the liquid channel 28 is continued.

[0145] Subsequently, as illustrated in FIG. 17F, the head cleaning device 150a drives the nozzle valve 26 to move the nozzle valve 26 in the direction of an arrow G72. Thus, the second cleaning solution 82 in the liquid channel 28 flows from the liquid channel 28 into thenozzle 24. Arrows G73 indicate directions in which the second cleaning solution 82 flows from the liquid channel 28 into the nozzle 24. In response to the outflow of the second cleaning solution 82 into the nozzle 24, the coating liquid 8 in the nozzle 24 is discharged from the nozzle hole 240 to the first channel 703. By this discharge operation, the liquid 8 in the nozzle 24 is discharged, and the thickened liquid 8a closing the nozzle hole 240 is discharged.

[0146] Subsequently, as illustrated in FIG. 17G, the coating liquid 8 flows out or elutes into the first channel 703. Arrows G74 indicate directions in which the coating liquid 8 flows out or elutes into the first channel 703.

[0147] At this time, when it is necessary to continue to cause the coating liquid 8 in the nozzle 24 to flow out or elute, the head cleaning device 150a supplies the first cleaning solution 80 from the first cleaning solution tank 910 to the first channel 703 again by the first supply unit 800. An arrow G75 indicates a direction in which the first cleaning solution 80 flows in the first channel 703. As illustrated in FIG. 17H, when the first channel 703 is filled inside with the first cleaning solution 80, in other words, when the nozzle surface 250 is immersed in the first cleaning solution 80, the head cleaning device 150a stops supplying the first cleaning solution 80.

[0148] Subsequently, as illustrated in FIG. 171, the coating liquid 8 flows out or elutes into the first channel 703. Arrows G76 indicate directions in which the coating liquid 8 flows out or elutes into the first channel 703.

[0149] By the above procedure, the head cleaning device 150a can clean at least one of the nozzle 24 and the nozzle surface 250 of the liquid discharge head 1.

[0150] FIG. 18 is a flowchart illustrating a cleaning operation by the head cleaning device according to the second embodiment of the present invention. Note that description of operations similar to the operations described with reference to FIG. 11 will be omitted as appropriate, and differences from FIG. 11 will be mainly described.

[0151] In step S62, the head cleaning device 150a supplies the second cleaning solution 82 to the liquid discharge head 1 by the second supply unit 820 (see FIG. 17C). Thereafter, the head cleaning device 150a continues the supply of the second cleaning solution 82 by the second supply unit 820 until the supply of the second cleaning solution 82 is stopped.

[0152] Subsequently, in step S63, the head cleaning device 150a determines whether the liquid discharge head 1 has been cleaned by the supply of the second cleaning solution. The cleaning completion may be determined, for example, on the basis of the supply time of thesecond cleaning solution 82, or may be determined according to a detection result of the cleaning state by a sensor provided in the liquid channel 28. Also at the time of this determination, the supply of the second cleaning solution 82 from the second cleaning solution tank 830 to the liquid discharge head 1 is continued. The fifth switching valve 880 on the downstream side of the liquid discharge head 1 closes the valve so as to stop discharging the second cleaning solution 82 to the second waste liquid tank 870.

[0153] Subsequently, in step S64, the head cleaning device 150a causes the first supply unit 800 to supply the first cleaning solution 80 to the capping unit 700 (see FIG. 17D).

[0154] In step S67, the head cleaning device 150a executes an opening / closing operation of the nozzle valve 26. For example, the head cleaning device 150a opens the nozzle valve 26. By executing the opening and closing operation of the nozzle valve 26, at least one of the thickened liquid 8a and the air layer 8b can be discharged to the first channel 703 (see FIG. 17F). Since the liquid channel 28 is filled with the second cleaning solution 82, the cleaning property in the nozzle 24 is improved by a discharge operation.

[0155] In step S69, the head cleaning device 150a determines whether or not to supply the first cleaning solution 80 to the first channel 703 again in order to cause the coating liquid in the nozzle 24 to flow out or elute.

[0156] In step S69, when it is determined to supply the first cleaning solution 80 (step S69, YES), the head cleaning device 150a closes the nozzle valve 26 in step S70. Thereafter, the operations in and after step S64 are performed again. On the other hand, when it is determined not to supply the first cleaning solution 80 (step S69, NO), the head cleaning device 150a closes the nozzle valve 26 in order to end the head cleaning operation in step S71. Thereafter, in step S72, the first supply unit 800 supplies the first cleaning solution 80 to the first channel 703 for refreshing. Thereafter, the head cleaning device 150a continues the supply of the first cleaning solution 80 by the first supply unit 800 until the supply of the first cleaning solution 80 is stopped.

[0157] Subsequently, in step S73, the head cleaning device 150a causes the first supply unit 800 to stop supplying the first cleaning solution 80 to the first channel 703, and causes the second supply unit 820 to stop supplying the second cleaning solution 82 to the liquid channel 28.

[0158] Subsequently, in step S74, the head cleaning device 150a causes the first compressor 920 to supply the air 90 to the first channel 703 to cause the first cleaning solution 80 in the first channel 703 to be discharged, and causes the second compressor 840 to supply air to theliquid channel 28 to cause the second cleaning solution 82 in the liquid channel 28 to be discharged.

[0159] The head cleaning device 150a can perform the cleaning operation according to the second embodiment of the present invention according to the procedure illustrated in FIG. 18. In the example illustrated in FIG. 18, the procedure of cleaning at least one of the nozzle 24 and the nozzle surface 250 using the capping unit 700 after the completion of cleaning of the liquid channel 28 of the liquid discharge head 1 has been described. However, the procedure of the cleaning operation according to the second embodiment of the present invention is not limited to this procedure. For example, the cleaning of the liquid channel 28 of the liquid discharge head 1 and the cleaning of at least one of the nozzle 24 and the nozzle surface 250 using the capping unit 700 may be performed in parallel.

[0160] Third EmbodimentNext, a channel member of a head cleaning device according to a third embodiment of the present invention will be described. FIG. 19 is a diagram illustrating a channel member702 of a head cleaning device according to the third embodiment of the present invention.

[0161] The third embodiment of the present invention is mainly different from the first embodiment in that the channel member 702 includes a recess 704 disposed to face the nozzle hole 240 disposed on the nozzle surface 250 when the capping unit 700 forms a sealed space.

[0162] By disposing the recess 704, the channel member 702 can hold the first cleaning solution 80 having a larger volume in a region facing the nozzle hole 240 in the first channel703 than in a region other than the region facing the nozzle hole 240 in the first channel 703. Thus, the channel member 702 prevents the coating liquid 8 flowing out or eluted into the first channel 703 from being mixed with the first cleaning solution 80 in the vicinity of the nozzle hole 240 and lowering the solubility. By supplying the first cleaning solution 80, retention indicated by an arrow G80 occurs in the recess 704, so that the channel member 702 can cause the coating liquid 8 to more easily elute from the nozzle hole 240 . At least one of the recess 704 and a groove can be disposed at a position facing the nozzle hole 240 disposed on the nozzle surface 250. Effects other than those described above in the third embodiment of the present invention are similar to the effects of the first embodiment of the present invention.

[0163] Fourth EmbodimentNext, a channel member of a head cleaning device according to a fourth embodiment of the present invention will be described. FIG. 20 is a diagram illustrating a channel member 702 of a head cleaning device according to the fourth embodiment of the present invention.

[0164] The fourth embodiment of the present invention is mainly different from the first embodiment in that the channel member 702 includes a protrusion 705 disposed to face the nozzle hole 240 of the nozzle 24 when the capping unit 700 forms a sealed space.

[0165] The protrusion 705 has an inclined surface in which the downstream side becomes gradually higher than the upstream side in the direction in which the first cleaning solution 80 flows (directions of arrows G90). The first cleaning solution 80 having passed through the position where the protrusion 705 is disposed easily flows toward the nozzle hole 240 according to the shape of the inclined surface as indicated by an arrow G91.Thus, the channel member 702 can cause the coating liquid 8 in the nozzle 24 to be easily discharged to the first channel 703. Effects other than those described above in the fourth embodiment of the present invention are similar to the effects of the first embodiment of the present invention.

[0166] Fifth embodimentNext, a control unit 5 included in a head cleaning device according to a fifth embodiment of the present invention will be described with reference to FIG. 21. FIG. 21 is a block diagram illustrating a functional configuration of a control unit 5 included in the head cleaning device according to the fifth embodiment of the present invention. Note that the control unit 5 may further include a functional configuration other than the functional configuration illustrated in FIG. 21.

[0167] The control unit 5 illustrated in FIG. 21 includes a data accumulation unit 85, a learning unit 86, and an estimation unit 87. The functions of the data accumulation unit 85, the learning unit 86, and the estimation unit 87 may be implemented by a machine learning program mounted on the control unit 5.

[0168] Example of Updating Immersion Time T by Machine EeamingThe data accumulation unit 85 accumulates data including at least the number of times of fdling (al, a2, ...), the immersion time T, and the content of the coating material in the cleaning solution (in a state where the cleaning solution and the dissolved coating material are mixed) discharged from the corresponding capping in each filling to the waste liquid tank. Data of the number of times of cleaning and the content of the coating material for each of the plurality of immersion times T is also accumulated.

[0169] On the basis of the data accumulated in the data accumulation unit 85, the learning unit 86 learns the relationship between the number of times the cleaning solution is fdled (al, a2, ...) in the channel between the head and the capping and the coating material content P of the discharged cleaning solution after each filling.

[0170] For example, the learning unit 86 may generate a learned model 88 in which the relationship between the number of times of fdling (al, a2, ...) and the coating material content P is learned using a data set in which the number of times of fdling (al, a2, ...) and the coating material content P stored in the data accumulation unit 85 are associated with each other as teacher data, and cause the estimation unit 87 to hold the learned model.

[0171] The algorithm used in the learning unit 86 is not particularly limited, and deep learning by a neutral network, an unsupervised learning model, a supervised learning model, a reinforcement learning model, or the like can be applied.

[0172] The estimation unit 87 estimates a predetermined value of the number of times of fdling (al, a2, ...) on the basis of learning of the learning unit 86. For example, when a value indicating an allowable number of times of fdling (al, a2, ...) is input, the estimation unit 87 inputs the input value to the learned model 88 and estimates a predetermined value of the immersion time T output from the learned model 88.

[0173] The control unit 5 controls the time for immersing the cleaning solution on the basis of the predetermined value of the immersion time T estimated by the estimation unit 87.

[0174] Since the head cleaning device according to the fifth embodiment of the present invention includes the control unit 5 illustrated in FIG. 21, the immersion time T can be adjusted using the learned model by machine learning.

[0175] Example of Updating Number of Times of Nozzle Opening and Closing by Machine learningThe data accumulation unit 85 accumulates data including at least the number of times of fdling (al, a2, ...), the immersion time T, the content of the coating material in the cleaning solution (a state in which the cleaning solution and the dissolved coating material are mixed) discharged from the corresponding capping in each filling to the waste liquid tank, and the number of times of opening of the nozzle. Data of the number of times of cleaning and the content of the coating material for each of the plurality of immersion times T is also accumulated.

[0176] On the basis of the data accumulated in the data accumulation unit 85, the learning unit 86 learns the relationship among the number of times the cleaning solution is fdled (al, a2, ...) in the channel between the head and the capping, the coating material content P of the discharged cleaning solution after each filling, and the number of times of opening of the nozzle.

[0177] For example, with a data set in which the number of times of filling (al, a2, ...), the coating material content P, and the number of times of opening of the nozzle stored in the data accumulation unit 85 are associated as teacher data, the learning unit 86 may generate a learned model 88 in which a relationship between the number of times of filling (al, a2, ...), the coating material content P, and the number of times of opening of the nozzle is learned and cause the estimation unit 87 to hold the model.

[0178] The algorithm used in the learning unit 86 is not particularly limited, and deep learning by a neutral network, an unsupervised learning model, a supervised learning model, a reinforcement learning model, or the like can be applied.

[0179] The estimation unit 87 estimates a predetermined value of the number of times of opening of the nozzle on the basis of the learning of the learning unit 86. For example, when a value indicating the allowable number of times of filling (al, a2, ...) is input, the estimation unit 87 inputs the input value to the learned model 88, and estimates a predetermined value of the immersion time T and the number of times of opening of the nozzle output from the learned model 88.

[0180] The control unit 5 controls the time for immersing the cleaning solution on the basis of the immersion time T estimated by the estimation unit 87 and a predetermined value of the number of times of opening of the nozzle.

[0181] Since the head cleaning device according to the fifth embodiment of the present invention includes the control unit 5 illustrated in FIG. 21, the immersion time T and the number of times of opening of the nozzle can be adjusted using the learned model by machine learning.

[0182] Sixth EmbodimentNext, a scanning method of the liquid discharge head 1 in the coating apparatus according to the sixth embodiment of the present invention will be described with reference to FIG. 22. FIG. 22 is a diagram illustrating a scanning method of the liquid discharge head 1 in a coating apparatus 100S according to the sixth embodiment of the present invention.

[0183] The coating apparatus 100S includes a head 1 IS, a first guide portion 800S that moves the head 1 IS in a main scanning direction (X-axis direction) of the head 1 IS, a fixed guide portion 810S that unitizes the head 1 IS and the first guide portion, and a second guide portion 820S that moves the head 1 IS in a vertical direction (Y-axis direction) intersecting the scanning direction. In the coating apparatus 100S, the head 1 IS is provided to a member other than the robot arm.

[0184] As illustrated in FIG. 22, the head 1 IS of the coating apparatus 100S is provided to a carriage 31 IS of the first guide portion 800S, and is provided to be movable in the left-right direction (scanning direction). The head 1 IS and the first guide portion 800S are unitized by the fixed guide portion 8 IOS, and are provided to be movable in the vertical direction along the second guide portion 820S. Thus, the head 1 IS can scan in a two-dimensional direction along the first guide portion 800S and the second guide portion 820S, and can apply the liquid to the object.

[0185] The head 1 IS can be replaced with the liquid discharge head 1 illustrated in FIG. 6 described above. The coating apparatus 100S includes the head cleaning device 150 described above. The head cleaning device 150 can seal the head 1 IS with the capping unit 700 and clean at least one of the nozzle 24 or the nozzle surface 250 of the head 1 IS. The coating apparatus 100S can also include the head cleaning device 150a described above. The head cleaning device 150a can seal the head 1 IS with the capping unit 700 to clean at least one of the nozzle 24 and the nozzle surface 250 of the head 1 IS and the liquid channel 28.

[0186] Although the preferred embodiment has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope described in the claims.

[0187] All numbers such as ordinal numbers and quantities used in the description of the embodiments of the present invention are exemplified to specifically describe the technology of the present invention, and the present invention is not limited to the exemplified numbers. Further, a connection relation between the components is exemplified for the purpose of describing the technology of the embodiments of the present invention, and the connection relation to enable the functions of the present disclosure is not limited to the connection relation as described above.

[0188] Aspects of the present invention are, for example, as follows.According to Aspect 1, a head cleaning device includes a liquid discharge head including a nozzle and a nozzle surface, a capping unit including a channel member that forms a first channel with the nozzle surface, a first supply unit to supply a first cleaning solution to the first channel ,and a control unit to control the first supply unit to supply the first cleaning solution to the first channel, stop the supply of the first cleaning solution in a state where the nozzle surface is immersed in the first cleaning solution, supply the first cleaning solution again after a predetermined immersion time has elapsed after the supply of the first cleaning solution is stopped, and stop the supply of the first cleaning solution again.According to Aspect 2, in the head cleaning device of Aspect 1, the control unit controls the liquid discharge head to discharge liquid in a state where the nozzle surface is immersed in the first cleaning solution.According to Aspect 3, in the head cleaning device of Aspect 1 or Aspect 2, the channel member has a surface facing the nozzle surface, and the surface has a substantially planar shape.According to Aspect 4, in the head cleaning device of any one of Aspect 1 to Aspect3, the channel member has at least one of a recess and a groove disposed to face a nozzle hole on the nozzle surface when the capping unit forms a sealed space.According to Aspect 5, in the head cleaning device of any one of Aspect 1 to Aspect4, the channel member has a protrusion disposed to face a nozzle hole on the nozzle surface when the capping unit forms a sealed space.According to Aspect 6, the head cleaning device according to any one of Aspect 1 to Aspect 5 further includes a vibration applying unit to apply vibration to the first cleaning solution flowing through the first channel.According to Aspect 7, the head cleaning device according to any one of Aspect 1 to Aspect 5 further includes a second supply unit to supply a second cleaning solution, in which the control unit controls: the second supply unit to supply the second cleaning solution to a second channel of the liquid discharge head, and the first supply unit to supply the first cleaning solution to the first channel after the second supply unit supplies the second cleaning solution to the second channel.According to Aspect 8, in the head cleaning device of any one of Aspect 1 to Aspect7, the liquid discharge head further includes a valve body to open and close a nozzle hole, and a drive means for opening and closing the valve body, and the drive means opens and closes the valve body when a sealed space is formed.According to Aspect 9, in the head cleaning device of any one of Aspect 1 to Aspect8, the capping unit forms a sealed space when contacting the liquid discharge head.According to Aspect 10, in the head cleaning device of any one of Aspect 1 to Aspect9, the first channel is formed to face the nozzle surface in a sealed space formed by the capping unit.According to Aspect 11, a coating apparatus includes the head cleaning device according to any one of Aspect 1 to Aspect 10.According to Aspect 12, a method for cleaning a head includes: supplying a first cleaning solution to a first channel formed by a nozzle surface of a liquid discharge head and a channel member, stopping the supplying of the first cleaning solution in a state where the nozzle surface is immersed in the first cleaning solution, supplying the first cleaning solution again after a predetermined immersion time has elapsed after the stopping of the supplying of the first cleaning solution, and stopping the supplying of the first cleaning solution again.The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of theabove teachings. For example, elements and / or features of different illustrative embodiments may be combined with each other and / or substituted for each other within the scope of the present invention. Any one of the above-described operations may be performed in various other ways, for example, in an order different from the one described above.This patent application is based on and claims priority to Japanese Patent Application No. 2023-201787, filed on November 29, 2023, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.[Reference Signs List]

[0189] 1 Liquid discharge head2 Coating robot3 Position detection unit4 Liquid supply unit5 Control unit6 Liquid reservoir7 Air supply unit8 Liquid8 a Thickened liquid8b Air layer9 Air regulator10 Base portion11 First arm12 Second arm13 Head unit16 Encoder sensor17 Robot drive unit20 Housing21 Supply port22 Collection port23 Discharge module24 Nozzle240 Nozzle hole25 Nozzle plate250 Nozzle surface26 Nozzle valve27 Piezoelectric element28 Liquid channel (example of second channel)40 Maintenance recovery unit80 First cleaning solution81 PortionSecond cleaning solution Data accumulation unit Learning unit Estimation unit Learned model Air , 100S Coating apparatus , 112 Air channel , 150a Head cleaning device Object Computer RIP unit Rendering unit Controller CPU ROM RAM HDD / SSD Interface (I / F) System control unit Nozzle valve drive control unit Discharge cycle signal generation unit Memory control unit Data storage unit Robot control signal generation unit First supply control unit Second supply control unit Head control device Robot control device A Input device Capping unit 1 Rubber member Channel member First channel Recess Protrusion Movable plate 1 Spring Substrate Supply port740 Discharge port800 First supply unit810 Coating liquid tank820 Second supply unit830 Second cleaning solution tank831 Second supply pipe840 Second compressor850 Third switching valve860 Fourth switching valve870 Second liquid drain tank871 Second discharge pipe880 Fifth switching valve1 IS Head31 IS Carriage800S First guide portion810S Fixed guide portion820S Second guide portion910 First cleaning solution tank911 First supply pipe920 First compressor930 First switching valve940 First waste liquid tank941 First discharge pipe950 Second switching valve820 Second supply unitA to F ArrowG10 to G12, G20 to G22, G30, G40 to G45, and G50 to G57 ArrowG60 to G67, G70 to G76, G80, and G90 to G91 ArrowS System bus

Claims

[CLAIMS]

1. A head cleaning device comprising: a liquid discharge head including a nozzle and a nozzle surface; a capping unit including a channel member that forms a first channel with the nozzle surface; a first supply unit to supply a first cleaning solution to the first channel; and a control unit to control the first supply unit to supply the first cleaning solution to the first channel, stop the supply of the first cleaning solution in a state where the nozzle surface is immersed in the first cleaning solution, supply the first cleaning solution again after a predetermined immersion time has elapsed after the supply of the first cleaning solution is stopped, and stop the supply of the first cleaning solution again.

2. The head cleaning device according to claim 1, wherein the control unit controls the liquid discharge head to discharge liquid in a state where the nozzle surface is immersed in the first cleaning solution.

3. The head cleaning device according to claim 1 or 2, wherein the channel member has a surface facing the nozzle surface, and the surface has a substantially planar shape.

4. The head cleaning device according to any one of claims 1 to 3, wherein the channel member has at least one of a recess and a groove disposed to face a nozzle hole on the nozzle surface when the capping unit forms a sealed space.

5. The head cleaning device according to any one of claims 1 to 4, wherein the channel member has a protrusion disposed to face a nozzle hole on the nozzle surface when the capping unit forms a sealed space.

6. The head cleaning device according to any one of claims 1 to 5, further comprising a vibration applying unit to apply vibration to the first cleaning solution flowing through the first channel.

7. The head cleaning device according to any one of claims 1 to 5, further comprising a second supply unit to supply a second cleaning solution, wherein the control unit controls: the second supply unit to supply the second cleaning solution to a second channel of the liquid discharge head, andthe first supply unit to supply the first cleaning solution to the first channel after the second supply unit supplies the second cleaning solution to the second channel.

8. The head cleaning device according to any one of claims 1 to 7, wherein the liquid discharge head further includes a valve body to open and close a nozzle hole, and a drive means for opening and closing the valve body, and the drive means opens and closes the valve body when a sealed space is formed.

9. The head cleaning device according to any one of claims 1 to 8, wherein the capping unit forms a sealed space when contacting the liquid discharge head.

10. The head cleaning device according to any one of claims 1 to 9, wherein the first channel is formed to face the nozzle surface in a sealed space formed by the capping unit.

11. A coating apparatus comprising the head cleaning device according to any one of claims 1 to 10.

12. A method for cleaning a head, the method comprising: supplying a first cleaning solution to a first channel formed by a nozzle surface of a liquid discharge head and a channel member; stopping the supplying of the first cleaning solution in a state where the nozzle surface is immersed in the first cleaning solution; supplying the first cleaning solution again after a predetermined immersion time has elapsed after the stopping of the supplying of the first cleaning solution; and stopping the supplying of the first cleaning solution again.

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