Liquid discharge apparatus and liquid discharge method

Abstract

A liquid discharge apparatus includes: a discharge unit including a nozzle capable of discharging liquid droplets to an object; a movement mechanism that moves the object and / or the discharge unit relative to each other in a relative movement direction; and a control unit configured to control an amount of one of the droplets and a landing interval of the one of the droplets on the object according to a landing position at which the one of the droplets lands on the object, and an incident angle of the one of the droplets with respect to a surface of the object.

Description

Technical Field

[0001] Embodiments of this disclosure relate to liquid discharge devices and liquid discharge methods. Background Technology

[0002] A liquid discharge device is known that discharges droplets from a nozzle and causes the liquid to adhere to an object.

[0003] For example, Patent Document 1 (Japanese Patent No. 4792701) discloses a liquid discharge device that, in order to improve the resolution of the discharge position, moves the discharge head at an angle relative to the direction of the nozzle array to control the timing of the discharge of liquid droplets.

[0004] Incidentally, when droplets are ejected in a direction that is inclined relative to the surface of the object, some droplets ejected onto the object may bounce back and turn into mist, making it difficult for the liquid to adhere well to the object. Summary of the Invention

[0005] Technical issues

[0006] The purpose of this invention is to suppress the formation of fog and enable the liquid to adhere well to the object.

[0007] Solution to the problem

[0008] In one aspect of the invention, a liquid discharge device is provided, comprising: a discharge unit including a nozzle capable of discharging droplets to an object; a moving mechanism for moving at least one of the object and the discharge unit relative to each other in a relative moving direction; and a control unit configured to control the amount of a droplet and the droplet landing interval on the object based on the landing position of a droplet landing on the object and the angle of incidence of the droplet relative to the surface of the object.

[0009] In another aspect of the invention, a liquid discharge device is provided, comprising: a discharge unit including nozzles for discharging droplets onto an object, the nozzles being arranged at a distance in an arrangement direction; a moving mechanism for moving at least one of the object and the discharge unit relative to each other; and a control unit configured to: discharge the droplets onto the object when the droplets land at a landing position on the object and the incident angle of the droplets is a predetermined angle greater than 0°; control the landing interval between adjacent droplets on the object to be less than the distance between the nozzles in the arrangement direction; and control adjacent landing droplets to partially overlap each other.

[0010] In another aspect of the invention, a liquid discharge method is provided, comprising: discharging droplets from a nozzle to an object; and controlling the amount of a droplet and the droplet landing interval on the object based on the landing position of a droplet on the object and the angle of incidence of the droplet relative to a surface of the object, so as to discharge the droplets to the object.

[0011] Effects of the present invention

[0012] According to embodiments of the present invention, the generation of fog can be suppressed, allowing the liquid to adhere well to the object. Attached Figure Description

[0013] A more complete understanding of the embodiments of the present disclosure and its many incidental advantages and features can be readily obtained and understood from the following detailed description with reference to the accompanying drawings.

[0014] [ Figure 1 ]

[0015] Figure 1 This is a diagram showing the overall structure of the liquid discharge device according to a first embodiment of the present invention.

[0016] [ Figure 2 ]

[0017] Figure 2 This is a diagram showing a more specific structure of the liquid supply unit according to a first embodiment of the present invention.

[0018] [ Figure 3 ]

[0019] Figure 3 This is a perspective view of the discharge unit according to the first embodiment of the present invention.

[0020] [ Figure 4 ]

[0021] Figure 4 This is a cross-sectional view of the discharge unit according to the first embodiment of the present invention.

[0022] [ Figure 5 ]

[0023] Figure 5 This diagram illustrates a painting process where the nozzle surface of the discharge unit is tilted relative to the surface of the object.

[0024] [ Figure 6 ]

[0025] Figure 6 It is a graph showing the relationship between the angle of incidence and the amount of fog.

[0026] [ Figure 7A ,7B and 7C]

[0027] Figure 7A , 7B 7C and 7C represent a liquid discharge method according to a first embodiment of the present invention.

[0028] [ Figure 8 ]

[0029] Figure 8 This is a block diagram illustrating the hardware structure of a coating system according to a first embodiment of the present invention.

[0030] [ Figure 9 ]

[0031] Figure 9 This describes the process for generating coating data according to the first embodiment of the present invention.

[0032] [ Figure 10 ]

[0033] Figure 10 This indicates the coating process according to the first embodiment of the present invention.

[0034] [ Figure 11 ]

[0035] Figure 11 This is a block diagram representing another hardware structure of the painting system.

[0036] [ Figure 12 ]

[0037] Figure 12 This refers to the painting process based on another hardware structure.

[0038] [ Figure 13A , 13B [13C and 13D]

[0039] Figure 13A , 13B 13C and 13D denote a liquid discharge method according to a second embodiment of the present invention.

[0040] [ Figure 14 ]

[0041] Figure 14 Examples showing different incident angles for each nozzle.

[0042] [ Figure 15 ]

[0043] Figure 15 An example of a reference for determining the angle of incidence.

[0044] [ Figure 16 ]

[0045] Figure 16 This indicates the center of the nozzle arrangement range when the nozzles are configured in two staggered rows.

[0046] [ Figure 17A and 17B ]

[0047] Figure 17A and 17B This indicates the change in the spacing between nozzles in the orthogonal direction of movement when the discharge unit with staggered nozzles is tilted relative to the direction of movement X.

[0048] [ Figure 18 ]

[0049] Figure 18 This is a block diagram of a control unit with machine learning capabilities.

[0050] [ Figure 19 ]

[0051] Figure 19 This illustrates another example of a liquid discharge device to which the present invention can be applied.

[0052] [ Figure 20 ]

[0053] Figure 20 This illustrates another example of a liquid discharge device to which the present invention is applicable.

[0054] The accompanying drawings are intended to illustrate embodiments of this disclosure and should not be construed as limiting its scope. Unless explicitly stated otherwise, the drawings should not be considered to be drawn to scale. Furthermore, throughout several views, the same or similar reference numerals denote the same or similar parts. Detailed Implementation

[0055] In describing the embodiments shown in the accompanying drawings, specific terminology has been used for clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology chosen, and it should be understood that each particular component includes all technical equivalents that have similar functionality, operate in a similar manner, and achieve similar results.

[0056] Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings. 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.

[0057] In the following description, some embodiments will be illustrated with reference to the accompanying drawings. Referring now to the drawings, wherein like reference numerals denote like or corresponding parts in several views, a liquid discharge device according to embodiments of the present disclosure is described below.

[0058] Overall structure of liquid discharge device

[0059] First, refer to Figure 1 The overall structure of the liquid discharge device according to the first embodiment of the present invention will be described.

[0060] As an example of a liquid discharge device, a painting apparatus 100 is shown here, which discharges liquid droplets onto the body of a car, which is the object 200, for painting. The object 200 can be, in addition to the body of a car, the fuselage of an aircraft, the hull of a ship, or other three-dimensional structures.

[0061] like Figure 1 As shown, the coating equipment 100 of the first embodiment of the present invention includes four coating robots 2.

[0062] The painting robot 2 includes, for example, a base 10 disposed on the ground; a first arm 11 disposed on the base 10; a second arm 12 connected to the first arm 11; and a head unit 13 disposed at the front end of the second arm 12. The first arm 11 and the second arm 12 of the painting robot 2 are robot arms that are rotatably and swingably connected to each other via joints, and function as a movement mechanism to move the head unit 13 to a desired position by driving rotation or swinging.

[0063] Specifically, the first arm 11 is configured to be able to move relative to the base portion 10 towards Figure 1 It can rotate in the direction of arrow A and swing in the direction of arrow B. The second arm 12 is configured to be able to rotate relative to the front end of the first arm 11. Figure 1 It can rotate in the direction of arrow C and swing in the direction of arrow D. The head unit 13 can rotate relative to the front end of the second arm 12. Figure 1 The painting robot 2 is installed in a manner that allows it to rotate in the direction of arrow E and swing in the direction of arrow F. The number of painting robots 2 is not limited to four; it can also be one, two, three, or more than five.

[0064] The head unit 13 includes a droplet discharge unit 1 for discharging droplets and a position detection unit 3 for detecting the position of the object 200. The droplet discharge unit 1 has multiple nozzles for discharging droplets. The position detection unit 3 is integrally mounted with the droplet discharge unit 1 at the front end of the second arm 12. The position detection unit 3 may include, for example, a stereo camera that detects the three-dimensional position information of three or more feature points on the object 200. The stereo camera may include multiple cameras. The position detection unit 3 acquires a distance image of the object 200 by triangulation based on the parallax between images captured by the multiple cameras.

[0065] In addition to the coating robot 2, the coating equipment 100 of the first embodiment of the present invention also includes a liquid supply unit 4 and a control unit 5.

[0066] The liquid supply unit 4 includes a liquid storage unit 6 and an air supply unit 7. The liquid storage unit 6 is, for example, a tank that stores liquids 8 such as paint. The air supply unit 7 is, for example, a compressor that supplies air to the liquid storage unit 6. When air is supplied from the air supply unit 7 to the liquid storage unit 6, the interior of the liquid storage unit 6 is pressurized. The liquid 8 within the liquid storage unit 6 is supplied to the discharge unit 1, where it is discharged as droplets from the nozzle of the discharge unit 1. In addition to droplets, the discharge unit 1 can also discharge liquid in a linear fashion. Figure 1 The diagram only shows the path for supplying liquid 8 to one discharge unit 1, but the same applies to supplying liquid 8 from the liquid storage unit 6 to all discharge units 1. Alternatively, multiple liquid storage units 6 can be prepared to hold liquids of different colors or types, allowing for the switching of supplying different colored or type liquids to each discharge unit 1.

[0067] In addition to the pre-input shape data of the object 200 and the image data for painting, the control unit 5 also controls the actions of each painting robot 2 and the discharge actions of each discharge unit 1 based on the position information of the object 200 detected by each position detection unit 3. As a result, the head unit 13 moves along the shape of the object 200. Thus, droplets are discharged from the discharge unit 1 onto the surface of the object 200. Figure 1 The diagram only shows the signal lines from the control unit 5 to one painting robot 2 and one discharge unit 1, and the signal lines from one position detection unit 3 to one control unit 5. However, the control unit 5 controls the actions of all the painting robots 2 and all the discharge units 1, and receives detection signals from all the position detection units 3.

[0068] Figure 2 This is a diagram showing a more specific structure of the liquid supply unit 4 according to the first embodiment of the present invention.

[0069] like Figure 2 As shown, the liquid supply unit 4, in addition to the liquid storage unit 6 and the air supply unit 7, also includes multiple air conditioners 9. The air conditioners 9 are disposed in the airflow path 111 connecting the air supply unit 7 and the multiple liquid storage units 6. The air conditioners 9 regulate the air pressure supplied from the air supply unit 7 to each liquid storage unit 6. Each of the multiple liquid storage units 6 is individually connected to each discharge unit 1 via the airflow path 112. Liquid 8 is supplied from each liquid storage unit 6 to each discharge unit 1 by pressurizing the interior of each liquid storage unit 6. Alternatively, the liquid storage units 6 may not be provided for each discharge unit 1. However, a single liquid storage unit can be provided for all discharge units 1.

[0070] Structure of the discharge unit

[0071] Next, refer to Figure 3 and Figure 4 The structure of the discharge unit 1 according to the first embodiment of the present invention will be described. Figure 3 This is a perspective view of the discharge unit 1 according to the first embodiment of the present invention. Figure 4 This is a cross-sectional view of the discharge unit 1 according to the first embodiment of the present invention.

[0072] like Figure 3 As shown, the discharge unit 1 includes a housing 20 and a supply port 21 and a recovery port 22 disposed on the housing 20.

[0073] like Figure 4 As shown, multiple discharge modules 23 are arranged in one or more rows within the housing 20. Each discharge module 23 includes a nozzle plate 25, a nozzle valve 26, a piezoelectric element 27, and a liquid flow path 28. The nozzle plate 25 is provided with nozzles 24 to discharge droplets from each discharge module 23. The nozzles 24 can be opened via the nozzle valve 26. The piezoelectric element 27 is a drive unit that opens and closes the nozzle valve 26 by extending or retracting it when a voltage is applied. The liquid flow path 28 is interconnected among the discharge modules 23 to form a common flow path. The liquid flow path 28 is also connected to a supply port 21 and a recovery port 22.

[0074] When liquid is supplied into the housing 20 from the supply port 21 with the valve at the recovery port 22 closed, the liquid flows into the liquid flow path 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. The nozzle 24 does not eject droplets. When voltage is applied to the piezoelectric element 27, the nozzle valve 26 is activated, opening the nozzle 24. Droplets are discharged from the nozzle 24. Liquid that does not discharge from the nozzle 24 is discharged to the outside through the recovery port 22.

[0075] Problems of fog generated during painting

[0076] Hereinafter, the fog generated during coating will be described using the structure of the first embodiment of the present invention as an example.

[0077] In a structure where the discharge unit 1 can be moved by the painting robot 2 to discharge droplets at a desired angle, similarly to the first embodiment of the present invention, the nozzle surface of the discharge unit 1 (also referred to as...) can be... Figure 4 The nozzle plate 25 shown is configured parallel to the surface of the object 200, thus enabling good painting. In the case of painting three-dimensional structures with complex shapes, such as vehicle bodies, etc., Figure 5As shown, sometimes it is necessary to perform coating with the nozzle surface 15 of the discharge unit 1 tilted relative to the surface 201 of the object 200. In this case, some droplets 29 discharged to the object 200 bounce back and turn into mist, making it difficult for the liquid to adhere well to the object 200. In the part where coating is performed with the nozzle surface 15 tilted relative to the surface 201 of the object 200, the generated mist can sometimes make it difficult to coat well, and the coating quality may be reduced.

[0078] The amount of mist produced by the rebounding droplets varies depending on the angle of incidence of the droplets relative to the surface of the object. The "angle of incidence" refers to... Figure 5 The angle α shown refers to the inclination of the droplet 29's landing direction or the normal direction of the nozzle surface 15 relative to the normal direction of the object 200's surface 201 at the landing position of the droplet 29.

[0079] Figure 6 It is a graph showing the relationship between the angle of incidence and the amount of fog.

[0080] exist Figure 6 In the figure, the three curves represented by the solid line, the dotted line, and the double dotted line respectively represent the relationship between the incident angle and the amount of mist when the amount (volume) of a droplet discharged from the nozzle is different.

[0081] In the three curves, the solid line represents the case with the largest liquid volume, the dashed line represents the case with the second largest liquid volume, and the double-dotted line represents the case with the smallest liquid volume. According to... Figure 6 The relationship shown indicates that, in all cases, the amount of fog tends to increase with increasing incident angle. Even at the same incident angle, the amount of fog increases when the volume of a droplet is larger than when the volume of a droplet is smaller. The amount of fog varies not only with the incident angle but also with the volume of a single droplet. That is, the larger the incident angle, the more fog is produced. The more liquid a droplet contains, the more fog is produced.

[0082] As mentioned above, fog tends to increase with increasing incident angle or the amount of liquid in a droplet. Considering this relationship, it can be said that reducing the amount of liquid in a droplet reduces the amount of fog. Simply reducing the amount of liquid in a droplet reduces the amount of liquid that needs to be discharged onto the object. This, in turn, creates other problems, such as reduced coating thickness or substrate exposure.

[0083] In this invention, a liquid discharge method is proposed to suppress fog and ensure good adhesion of liquid to the object. The liquid discharge method according to the first embodiment of this invention will now be described.

[0084] Liquid discharge method according to the first embodiment of the present invention

[0085] Figure 7A ,7B Figures 7 and 7C represent a liquid discharge method according to a first embodiment of the present invention.

[0086] Figure 7A-1 7A-3 represents the tilt β (β1) of the nozzle array, the landing area S (S1) of each droplet 29, and the landing intervals Px and Py (Px1 and Py1) of the droplets 29 when the incident angle α is α1 (e.g., 0°). Figure 7B-1 to Figure 7B-3 This represents the inclination β(β2) of the nozzle array, the landing area S(S2) of each droplet 29, and the landing intervals Px and Py(Px2 and Py2) of the droplets 29 when the incident angle α is greater than the incident angle α1 by an angle α2. Similarly, Figure 7C-1 to Figure 7C-3 This represents the nozzle array tilt β(β3), the landing area S(S3) of each droplet 29, and the landing intervals Px and Py(Px3 and Py3) of the droplets 29 when the incident angle α is greater than the incident angle α2 by an angle α3. Figure 7A , Figure 7B and Figure 7C In each of these figures, the diagram denoted as <Angle of Incidence> is a side view of the discharge unit 1 viewed from the side. The diagram denoted as <Inclination of the Nozzle Array> is a top view of the discharge unit 1 viewed from above. The diagram denoted as <Landing Area and Landing Interval> is a top view of the landing point of the droplet 29 on the surface 201 of the object 200 viewed from above.

[0087] "Inclination β of the nozzle array" refers to the inclination of the arrangement direction of the nozzles 24 relative to the moving direction X of the discharge unit 1 when the discharge unit 1 moves along the surface 201 of the object 200. The arrangement direction of the nozzles 24 refers to the direction in which the nozzles 24 are arranged longest when they are not arranged in a row but in an alternating or grid pattern.

[0088] "The landing area S of droplet 29" refers to the area of ​​one droplet 29 that lands on the surface 201 of object 200. "The landing interval Px, Py of droplets 29" refers to the landing interval between adjacent droplets 29, including the landing interval Px in the moving direction X of the discharge unit 1 and the landing interval Py in the moving orthogonal direction Y that is orthogonal to the moving direction X.

[0089] In the first embodiment of the present invention, as Figure 7A , 7B As shown in Figure 7C, as the incident angle α increases (α1 < α2 < α3), the landing area S of each droplet 29 decreases (S1 > S2 > S3). That is, as the incident angle α increases ( Figure 6 Fog may easily form, so when the incident angle α is large, the volume of a droplet is reduced to decrease the landing area S of each droplet. Figure 8The nozzle valve drive control unit 402 shown can adjust the amount of each droplet 29 by changing any one or two or more of the opening time of each nozzle 24, the opening amount of each nozzle 24, and the discharge pressure of the droplets 29. When the incident angle α is large, the nozzle valve drive control unit 402 can reduce the amount of droplets 29 by shortening the opening time of each nozzle 24, reducing the opening amount of each nozzle 24, and reducing the discharge pressure of the droplets 29. As a result, the amount of mist can be reduced.

[0090] If the amount of each droplet 29 is simply reduced, the amount of liquid discharged into the object 200 is also reduced. When the incident angle α is large in the first embodiment of the invention, the landing intervals Px and Py of the droplets 29 are also shortened (Px1>Px2>Px3 and Py1>Py2>Py3).

[0091] In this case, the landing interval Px in the movement direction X and the landing interval Py in the orthogonal movement direction Y both become shorter.

[0092] Depend on Figure 8 The robot control device 600 shown can change the moving speed of the discharge unit 1, by Figure 8 The head control device 500 shown can change the time interval between the discharge of adjacent droplets 29 from the discharge unit 1 as shown in FIG. 7. By changing at least one of the moving speed of the discharge unit 1 and the time interval, the landing interval Px in the moving direction X can be adjusted. When the incident angle α is large, the landing interval Px in the moving direction X can be shortened (Px1>Px2>Px3) by either or both of slowing down the moving speed of the discharge unit 1 and shortening the time interval between the discharged droplets 29. Even when the number of nozzles 24 is only one, the landing interval Px in the moving direction X can be adjusted in the same way.

[0093] like Figure 7A , Figure 7B , Figure 7C As shown, by changing the tilt β of the nozzle array, the landing interval Py in the orthogonal direction of movement Y can be changed. When the incident angle α is large, the robot control device 600 controls the orientation of the discharge unit 1 to reduce the tilt β of the nozzle array (β1>β2>β3), thereby shortening the landing interval Py in the orthogonal direction of movement Y (Py1>Py2>Py3).

[0094] In the first embodiment of the present invention, as described above, when the incident angle α is large, the head control device 500 reduces the amount of droplet 29 and shortens the landing intervals Px and Py of droplet 29, thus discharging droplet 29. As a result, when the incident angle α is large, the amount of droplet 29 is reduced to suppress fogging. Consequently, even if the landing area S of a single droplet 29 is reduced, by shortening the landing intervals Px and Py between droplets 29, the amount of liquid adhering per unit area can be ensured. According to the first embodiment of the present invention, the thickness of the coating film can be well ensured without exposing the substrate. Thus, fog suppression and good liquid adhesion can be achieved, and coating quality can be improved.

[0095] In the first embodiment of the invention, the landing intervals Px and Py in both the movement direction X and the orthogonal movement direction Y of the discharge unit 1 are shortened. However, it is possible to shorten only one landing interval. In this case, it is also possible to increase the amount of liquid adhering per unit area. Therefore, an improvement in coating quality can be expected. In order to more reliably prevent coating defects and improve coating quality, it is preferable to shorten the landing intervals Px and Py in both the movement direction X and the orthogonal movement direction Y.

[0096] In the first embodiment of the present invention, as Figure 7A , Figure 7B , Figure 7C As shown, as the incident angle α increases, the landing area S and the landing intervals Px and Py decrease from... Figures 7A to 7B ,from Figures 7B to 7C The change occurs in two phases. However, this increase can also be responded to with a single-phase change. That is, when the incident angle α is greater than... Figure 7A The incident angle α shown Figure 7B The occasion and the incident angle α is greater than Figure 7A The incident angle α shown Figure 7C occasions, for example, with Figure 7C Similarly, the landing area S and landing intervals Px and Py can be changed in only one stage. Even in this case, it is possible to ensure the amount of liquid adhering per unit area while suppressing fog. However, when the incident angle α is... Figure 7B Given the incident angle α, if the landing area S and landing intervals Px and Py are changed to... Figure 7C The shape shown is related to the landing area S and the landing intervals Px and Py. Figure 7B Compared to the configuration shown, the coating area per unit time is reduced. Therefore, there is a concern that the coating time will be longer. In order to perform coating efficiently while ensuring coating quality, it is preferable, as in the first embodiment of the present invention, to vary the landing area S and landing intervals Px and Py in two or more stages according to the magnitude of the incident angle α.

[0097] Hardware structure of the coating system

[0098] Figure 8 This is a block diagram illustrating the hardware structure of the coating system according to the first embodiment of the present invention.

[0099] like Figure 8 As shown, the painting system 1000 according to the first embodiment of the present invention, in addition to multiple painting robots 2, also includes an input device 700, a computer 300, a controller 400, a head control device 500, and a robot control device 600. Here, only two painting robots 2 are shown, and the remaining painting robots 2 are omitted.

[0100] Each painting robot 2 is equipped with an encoder sensor 16 and a robot drive unit 17. The encoder sensor 16 is, for example, an optical sensor that optically detects the slits of the encoder located at the connection points between the base 10 and the first arm 11, the first arm 11 and the second arm 12, and the second arm 12 and the head unit 13 of the painting robot 2. Through the detection of the encoder sensor 16, the rotation and swing of the first arm 11, the second arm 12, and the head unit 13 can be determined, thus enabling the acquisition of the three-dimensional position information of the head unit 13. The robot drive unit 17 is a drive unit that performs the rotation and swinging movements of the first arm 11, the second arm 12, and the head unit 13.

[0101] The input device 700 is a device for inputting information related to the shape data, painting image data, coordinate data, painting pattern, painting range (painting start position, painting end position), and painting instructions of the object 200. The input device 700 may include, for example, a keyboard, mouse, or touch panel used by the user to perform input operations. Various information input to the input device 700 is sent to the computer 300.

[0102] Computer 300 includes: a Routing Information Protocol (RIP) unit 301 that performs image processing on image data received from input device 700; and a rendering unit 302 that decomposes the image data into coating data for each scan of each head unit 13. Computer 300 receives shape data of object 200 from input device 700, acquires actual position information of object 200 detected by position detection unit 3, and generates a coating path for each coating robot 2 based on the shape data and actual position information of object 200. Computer 300 calculates the incident angle α of the droplet relative to object 200 in the generated coating path. The incident angle α is calculated using one or more of the following: the shape data of object 200 received from input device 700, the position information of object 200 detected by position detection unit 3, and the three-dimensional position information of head unit 13 detected by encoder sensor 16.

[0103] The controller 400, head control device 500, and robot control device 600 function as control units 5 that control the actions of each painting robot 2 and the discharge actions of each discharge unit 1. In this case, one head control device 500 and one robot control device 600 are each provided. However, the head control device 500 and the robot control device 600 may also be provided individually for each painting robot 2.

[0104] The controller 400 includes a system control unit 401, a nozzle valve drive control unit 402, a discharge cycle signal generation unit 403, a memory control unit 404, a data storage unit 405, and a robot control signal generation unit 406. The system control unit 401 receives coating data and command signals from the computer 300 and controls the overall operation of the coating system 1000. The system control unit 401 may include the functions of the RIP unit 301 and the drawing unit 302 included in the computer 300. The nozzle valve drive control unit 402 generates control signals for controlling the opening and closing of each nozzle valve 26 based on the coating data received from the computer 300 and the incident angle α. The discharge cycle signal generation unit 403 generates discharge cycle signals for each discharge unit 1 based on the output signals from each encoder sensor 16, the coating data received from the computer 300, and the incident angle α. The memory control unit 404 controls the data storage unit 405. The data storage unit 405 includes ROM (Read Only Memory), RAM (Random Access Memory), and HDD (Hard Disk Drive) memory to store coating data and coating range data received from the computer 300. The robot control signal generation unit 406 generates synchronization control signals to synchronize the driving action of each coating robot 2 with the droplet discharge action, based on the coating data and coating path information provided by the computer 300. The robot control signal generation unit 406 also generates control signals to determine the tilt β of the nozzle array of each discharge unit 1, based on the incident angle α calculated by the computer 300.

[0105] The head control device 500 receives a control signal from the nozzle valve drive control unit 402 and a discharge cycle signal from the discharge cycle signal generation unit 403, and controls the discharge amount and discharge timing of each discharge unit 1 based on the received control signal and discharge cycle signal. At this time, by controlling the discharge amount and discharge timing of each discharge unit 1 based on the incident angle α, the amount of discharged droplets and the landing interval Px in the movement direction X are controlled to be the amount of droplets and the landing interval corresponding to the incident angle α.

[0106] The robot control device 600 receives control signals from the robot control signal generation unit 406 and controls the drive of the robot drive unit 17 based on the received synchronization control signals. At this time, by controlling the robot drive unit 17 based on the incident angle α, the tilt β of the nozzle array of each discharge unit 1 is controlled. Furthermore, the landing interval Py in the orthogonal direction Y is controlled to be the landing interval corresponding to the incident angle α.

[0107] Coating data generation process

[0108] Next, refer to Figure 9 The process for generating coating data according to the first embodiment of the present invention will be described.

[0109] When starting to generate coating data, such as Figure 9 As shown, the computer 300 reads data related to the object 200 from the input device 700. Then, in step S11, coating data is generated from the read data. Based on this coating data, the actions of each coating robot 2 and the discharge actions of each discharge unit 1 are set.

[0110] In step S12, the computer 300 calculates the incident angle α of the droplets relative to the object 200 based on the coating data. As a result, when there is a coating section where the incident angle α is above a preset threshold T, in steps S13 and S14, the coating data is corrected to reduce the amount of discharged droplets and shorten the landing interval. That is, if the amount of droplets and the landing interval change, the actions of each coating robot 2 and the discharge actions of each discharge unit 1 change. Therefore, the coating data is corrected based on the actions after the change in the amount of droplets and the landing interval. In coating sections where the incident angle α is less than the threshold T, the amount of discharged droplets and the landing interval remain unchanged. The generated coating data is used. Through the above steps, the generation of coating data is completed.

[0111] Painting process

[0112] Next, refer to Figure 10 The coating process of the first embodiment of the present invention will be described.

[0113] When painting begins, such as Figure 10 As shown, in step S21, the controller 400 acquires the coating data generated by the computer 300. Then, based on the acquired coating data, the controller 400 controls each coating robot 2 to move the discharge unit 1 to the coating section of the object 200.

[0114] The controller 400 determines the incident angle α of the coating section based on the acquired coating data. As a result, when the incident angle α is less than a preset threshold T in step S22, for example... Figure 7AThe droplets are discharged in a manner that... When the incident angle α is equal to or greater than a preset threshold T in step S22, in step S23, compared to the case where the incident angle α is less than the threshold T, the amount of discharged droplets is reduced and the landing interval is shortened. For example, using... Figure 7B The droplets are discharged in the manner shown in 7C. Subsequently, similarly, for each coating section at the moving destination of each discharge unit 1, the incident angle α is confirmed by the controller 400, and the amount of droplets and the droplet landing interval are controlled according to the incident angle α.

[0115] Other hardware structure

[0116] Figure 11 This is a block diagram representing the other hardware structures of the painting system.

[0117] The hardware structure of the coating system according to the present invention can also be as follows: Figure 11 The hardware structure shown. Figure 11 The hardware structure shown is similar to Figure 8 The difference in the example shown is that the position detection unit 3 detects the position information of the object 200 in real time. The detected position information is not transmitted through the computer 300, but is directly input to the head control device 500 and the robot control device 600.

[0118] When painting begins, such as Figure 12 As shown, in this case, the controller 401 first acquires the coating data generated by the computer 300 in step S31. The coating data generation process is similar to... Figure 9 The process shown is the same. Therefore, its description is omitted. Next, the controller 400 controls each painting robot 2 based on the acquired painting data, so that the discharge unit 1 moves to the painting section of the object 200.

[0119] When the discharge unit 1 moves to the coating section of the object 200, the position detection unit 3 acquires the position information of the coating section in real time in step S32. Then, the acquired position information is directly input to the head control device 500 and the robot control device 600. The head control device 500 and the robot control device 600 control the actions of the coating robot 2 and the discharge unit 1 based on the input position information. At this time, in step S33, if the incident angle α of the coating section is above a preset threshold T, in step S34, compared to the case where the incident angle α is less than the threshold T, the amount of discharged droplets is reduced, and the landing interval is shortened, and droplets are discharged accordingly. Subsequently, similarly, for each coating section at the moving destination of each discharge unit 1, the amount of droplets and the landing interval of the droplets are controlled according to the incident angle α.

[0120] Second embodiment of the present invention

[0121] Figure 13A ,13B Figures 13C and 13D illustrate a liquid discharge method according to a second embodiment of the present invention.

[0122] In the second embodiment of the present invention, as Figure 13A , 13B As shown in Figures 13C and 13D, as the incident angle α increases from α1 to α2, α3, and α4, the head control device 500 controls the discharge volume and discharge interval of each discharge unit 1. The robot control device 600 controls the orientation of each discharge unit 1 to vary the landing area S and landing intervals Px and Py of each droplet 29 in three stages according to the incident angles α2 to α4. Therefore, the tilt β of the nozzle array also varies from β1 in three stages: β2, β3, and β4. In this way, by varying the landing area S and landing intervals Px and Py in three stages according to the incident angles α2 to α4, coating quality can be ensured, and more efficient coating can be performed.

[0123] In the second embodiment of the present invention, as Figure 13A As shown, when the incident angle α is 0°, the nozzle array is configured with an orientation of 90° relative to the moving direction X of the discharge unit 1. Thus, when the incident angle α is 0°, the tilt β of the nozzle array can be 90°. By setting the tilt β of the nozzle array to 90°, a wider landing interval Py can be ensured, especially in the orthogonal moving direction Y, thereby enabling efficient coating.

[0124] In short, in this invention, when the incident angle α is a predetermined angle greater than 0° (except for...) Figure 7A and Figure 13A In other cases, Figure 7A , Figure 7B and Figure 7C The illustrated embodiments and Figure 13A , Figure 13B , Figure 13C and Figure 13D In the illustrated embodiment, the discharge unit 1 is tilted relative to the direction of movement X, and droplets 29 are discharged from the nozzle 24. That is, in Figure 7B and Figure 7C In the case of and in Figure 13B , Figure 13C and Figure 13D In this case, the discharge droplets 29 are such that the interval Py between adjacent droplets 29 falling on the coating surface of the object 200 in the orthogonal direction of movement is smaller than the interval G between the nozzles 24 discharging the droplets 29 in the arrangement direction (in Figure 7A , Figure 7B and Figure 7C as well as Figure 13A , Figure 13B , Figure 13C and Figure 13D(as shown in the image), and causes local overlap of adjacent landing droplets 29. As a result, the amount of liquid adhering per unit area is ensured, thus improving coating quality.

[0125] The aforementioned "space G between the nozzles 24 that discharge droplets 29 in the arrangement direction" refers to the space between adjacent nozzles 24 in the arrangement direction among the nozzles 24 that actually discharge droplets. Therefore, when droplets 29 are discharged from only a portion of the nozzles 24, the space Py between adjacent falling droplets 29 in the orthogonal direction of movement Y is smaller compared to the space G between adjacent nozzles 24 in the arrangement direction within that portion of the nozzles 24.

[0126] The criterion for determining the angle of incidence

[0127] Next, an example of the basis for determining the incident angle α will be explained.

[0128] When the surface 201 of the object 200 is a curved surface, for example Figure 14 As shown, the incident angles α1 to α4 of nozzle 24 can also be different from each other. In this case, the tilt β of the nozzle array cannot be changed for each incident angle α1 to α4. Therefore, it is necessary to determine the incident angle α0 as the reference for setting the tilt β of the nozzle array.

[0129] For example, if we assume Figure 14 Using the incident angle α1 of the nozzle 24 at the left end as a reference, the smallest incident angle α1 among the four incident angles is used as the reference to determine the amount of droplets. Therefore, for the nozzle 24 at the right end with the largest incident angle α4, the droplet amount setting may be insufficient to suppress fog. That is, when the incident angle of either of the nozzles 24 located at both ends is used as a reference, the deviation (absolute value) from the incident angle of the other end becomes larger. Therefore, there is a possibility that the amount of droplets on the other end cannot be sufficiently reduced, resulting in fog formation.

[0130] When the incident angle α varies for each nozzle 24, it is preferable to... Figure 15 As shown, the incident angle α0 is determined with the center m of the arrangement range H of the nozzles 24 as a reference. In other words, the incident angle α0 is determined based on the center m of the arrangement range H of the nozzles 24. As a result, the maximum deviation (absolute value) between the incident angle α0 used as the reference and the incident angles α1 and α4 at both ends is reduced, and therefore, fog is less likely to be generated.

[0131] The location of the reference incident angle α0 is not limited to the center m of the arrangement range H of the nozzles 24. Other locations can also be used as the reference. For example, if the incident angle is always larger at the position of the nozzle 24 at one end, the position of that nozzle 24 can be used as the reference to determine the incident angle α0. When only some nozzles 24 discharge droplets, the center position of the arrangement range of the nozzles 24 that actually discharge droplets can be used as the reference to determine the incident angle α0.

[0132] The incident angle α0 that becomes the reference can be appropriately changed, for example, according to the shape of the object 200, the configuration of the nozzle 24, etc.

[0133] When the nozzles 24 are arranged in two staggered rows, such as Figure 16 As shown in the example, the center m of the arrangement range H of the nozzles 24 can also be set as the intersection of the diagonals of the parallelogram of the nozzles 24, and the position of the intersection point can be used as a reference to determine the incident angle α0.

[0134] In the case where the nozzles 24 are staggered, for example, as from Figure 17A The state shown Figure 17B As shown, if the discharge unit 1 is tilted relative to the movement direction X, the spacing V1 and V2 between the nozzles 24 in the orthogonal movement direction Y will be uneven. In this case, the spacing between adjacent droplets discharged from each nozzle 24 in the orthogonal movement direction Y will also be uneven, which may degrade the coating quality.

[0135] In the discharge unit 1 with staggered nozzles 24, when the discharge unit 1 is tilted relative to the moving direction X, the droplets are discharged from one of the upper and lower rows of nozzles 24 shown in FIG17.

[0136] In this case, the incident angle α0, which serves as the reference, is preferably determined by taking the center of the arrangement range of the nozzles 24 that actually discharge droplets from the above and below as the reference. If droplets are discharged from only a portion of the nozzles 24 listed above or below, the range from one end of the nozzle 24 that actually discharges droplets to the other end of the nozzle 24 can also be defined as the arrangement range, and the center of this arrangement range can be used as the reference to determine the incident angle α0.

[0137] Even when droplets are discharged from only one of the two rows of nozzles 24, it is possible to... Figure 16 The center m of the nozzle arrangement range H shown is used as a reference to determine the incident angle α0 used as a reference. Alternatively, the center of the arrangement range of nozzles 24 in a column different from the column that actually discharges droplets can be used as a reference to determine the incident angle α0 used as a reference.

[0138] When the incident angle α of a portion of the nozzles 24 is very large, even if the center of the arrangement range H of the nozzles 24 is used as a reference to determine the incident angle α0, it is sometimes difficult to effectively suppress the misting of droplets discharged from that portion of the nozzles 24. Therefore, when the incident angle α of a portion of the nozzles 24 exceeds a predetermined value, the discharge of droplets from that portion of the nozzles 24 can be stopped. As a result, the formation of mist can be prevented.

[0139] The predetermined value of the incident angle α, which is used as the criterion for deciding whether to discharge the droplet, may not be a fixed value set in advance, but a value updated by machine learning.

[0140] Machine learning configuration

[0141] Figure 18 This is a block diagram of control unit 5, which has machine learning capabilities.

[0142] Figure 18 The control unit 5 shown includes a data storage unit 85, a learning unit 86, and an estimation unit 87.

[0143] The functions of the data accumulation unit 85, the learning unit 86, and the estimation unit 87 can also be implemented by a machine learning program installed in the control unit 5.

[0144] The data accumulation unit 85 accumulates at least the object shape data, incident angle α, discharged droplet volume, nozzle array tilt β, landing interval Px, Py, and mist volume data.

[0145] Based on the data accumulated in the data accumulation unit 85, the learning unit 86 extracts the amount of mist under the predetermined incident angle α, and learns the relationship between the incident angle α, the amount of discharged droplets, and the tilt β of the nozzle array.

[0146] For example, the learning unit 86 can also establish corresponding data sets based on the incident angle α, the amount of discharged droplets, and the tilt β of the nozzle array stored in the data accumulation unit 85, using these as teacher data to generate a learned model 88 that has learned the relationship between the incident angle α, the amount of discharged droplets, and the tilt β of the nozzle array. Then, the learning unit can enable the estimation unit 87 to maintain this learned model.

[0147] There are no particular restrictions on the algorithm used in learning unit 86. For example, it can be applied to deep learning based on neural networks, unsupervised learning models, supervised learning models, and reinforcement learning models.

[0148] The estimation unit 87 estimates a predetermined value of the incident angle α, which serves as the criterion for determining whether to discharge droplets, based on the learning estimation performed by the learning unit 86. For example, when the input represents a value indicating the amount of fog that can be generated, the estimation unit 87 inputs the input value to the learned model 88 and estimates a predetermined value of the incident angle α output from the learned model 88.

[0149] The control unit 5 controls the amount of droplets discharged from the discharge unit 1 and the tilt β of the nozzle array based on a predetermined value of the incident angle α estimated by the estimation unit 87.

[0150] The liquid discharge device according to the present invention, due to having Figure 18 The control unit 5 shown can therefore use a learned model obtained through machine learning to adjust the amount of droplets discharged from the discharge unit 1 and the tilt β of the nozzle array.

[0151] Examples of other liquid discharge devices

[0152] The present invention is also applicable to liquid discharge devices having the following structure.

[0153] Figure 19 This is an example of a coating apparatus 800 that moves the object 200 to perform coating instead of dispensing unit 1. In this case, the coating apparatus 800 includes, for example, a robotic arm 90 that holds and moves the object 200 and a dispensing unit 1 fixed to a support table. While moving the object 200, the robotic arm 90 dispenses liquid from the dispensing unit 1 to the object 200. As a result, the liquid is applied to the object 200. The "movement" of the object 200 includes not only the case where the object 200 moves in a straight line or curve, but also the case where the object 200 rotates, causing its orientation relative to the dispensing unit 1 to change, and the case where the surface of the object 200 moves.

[0154] When the incident angle α between the object 200 and the discharge unit 1 is large, fog may occur even in the coating apparatus 800 with the structure described above, making it difficult to achieve good coating. When the incident angle α is large, it is preferable to reduce the amount of droplets (reduce the landing area) and the droplet landing interval, similar to the embodiments of the present invention. As a result, fog can be suppressed, and coating can be performed well.

[0155] The moving mechanism of the coating equipment of the present invention is not limited to a moving mechanism that moves either the object 200 or the discharge unit 1 relative to the other. The moving mechanism may also be a moving mechanism that moves both the object 200 and the discharge unit 1 relative to each other. The moving mechanism is not limited to a robotic arm; for example, it may be a linear actuator that moves at least one of the object 200 and the discharge unit 1 in a straight line in one direction, two mutually orthogonal directions, or three directions.

[0156] The discharge unit 1 of the present invention is not limited to including, for example, Figure 4 The nozzle plate 25 of the nozzle 24 shown. For example, as shown... Figure 20 As shown, the present invention can also be applied to a coating apparatus 900 in which the nozzle 24 protrudes from the discharge unit 1. In this case, the nozzle surface is either the front end surface 24a of the nozzle 24 or the outer surface 1a of the main body of the discharge unit 1.

[0157] This invention is also applicable to, for example, painting on automobile bodies for purposes other than coloring or design. For example, automobile body painting processes include primers for ensuring adhesion to the vehicle substrate and for rust prevention, intermediate coats for ensuring impact resistance and durability, and topcoats for coloring, design, etc. The painting equipment of this invention can be used for primer or intermediate coat painting, in addition to topcoat painting. After the topcoat, when there is a painting process for applying a protective layer (e.g., a clear coat) to achieve gloss and protection of the coating, the painting equipment according to this invention can be used for the process of applying the protective layer. Furthermore, when applying a peelable protective layer to protect the coated surface on an automobile during transport or in the factory, the painting equipment according to this embodiment can also be used to apply the protective layer. The peelable protective layer can be any layer, as long as it adheres to the coating surface of the vehicle body to chemically or physically protect the coating portion from dust, metal powder, oil, salt, acid, and ultraviolet radiation, and is preferably formed from a material comprising, for example, primarily an acrylic copolymer agent.

[0158] This invention is also applicable to liquid discharge devices that discharge droplets for purposes other than coating. For example, marking devices that discharge droplets onto an object to mark specific locations can be cited.

[0159] This invention is not limited to liquid discharge devices that discharge droplets onto three-dimensional objects such as vehicle bodies or building materials, but can also be applied to liquid discharge devices that discharge droplets onto planar objects such as sheets or plates. Even with planar objects, the angle of incidence of the droplets relative to the object's surface may change when the surface is curved. Therefore, by applying this invention, fog can be suppressed, allowing the liquid to adhere well to the object. This invention is preferably applicable even when the object's surface is flat, and when it is necessary to discharge droplets with the nozzle face inclined relative to the object's surface. In addition to the mechanism related to the transport of the object and the pretreatment equipment, the "liquid discharge device" of this invention may also include, for example, a post-treatment device.

[0160] If we summarize the various aspects of the present invention described above, the present invention includes at least the following aspects:

[0161] First aspect

[0162] According to a first aspect, a liquid discharging device includes: a discharging unit including a nozzle capable of discharging droplets to an object; and a moving mechanism for moving at least one of the object and the discharging unit relative to each other in a relative moving direction. The amount of a single droplet and the droplet landing interval on the object are controlled based on the landing position of the droplet on the object and the angle of incidence of the droplet relative to the surface of the object.

[0163] Second aspect

[0164] According to the second aspect, in the liquid discharge device of the first aspect, the droplet landing interval is controlled by changing the tilt of the nozzle arrangement direction relative to the relative movement direction.

[0165] Third aspect

[0166] According to the third aspect, in the liquid discharge device of the first or second aspect, the relative moving speed between the object and the discharge unit is changed to control the landing interval of the droplets.

[0167] Fourth aspect

[0168] According to the fourth aspect, in the liquid discharge device of any of the first to third aspects, the time interval for the discharge unit to discharge the droplets is changed to control the landing interval of the droplets.

[0169] Fifth aspect

[0170] According to the fifth aspect, in the liquid discharge device of any of the first to fourth aspects, the opening time or the opening amount of each of the nozzles is changed to control the amount of the droplet.

[0171] Sixth aspect

[0172] According to the sixth aspect, in the liquid discharge device of any of the first to fifth aspects, the discharge pressure of the discharge unit discharging the droplet is changed to control the amount of the droplet.

[0173] Seventh aspect

[0174] According to the seventh aspect, in the liquid discharge device of any of the first to sixth aspects, the amount of the droplet and the landing interval of the droplet are controlled according to the incident angle and vary in two or more stages.

[0175] Eighth aspect

[0176] According to the eighth aspect, in the liquid discharge device of any of the first to seventh aspects, the incident angle is determined based on the center of the arrangement range of the nozzles.

[0177] Ninth aspect

[0178] According to the ninth aspect, in the liquid discharge device of any of the first to eighth aspects, when the angle of incidence at a position of a portion of the nozzle exceeds a predetermined value, the control unit causes the discharge unit to stop discharging the droplets from that portion of the nozzle.

[0179] Tenth aspect

[0180] According to a tenth aspect, a liquid discharge device includes: a discharge unit comprising a nozzle for discharging droplets onto an object; and a moving mechanism for moving at least one of the object and the discharge unit relative to each other. The discharge unit discharges the droplets onto the object when the droplets land at a landing position on the object and the angle of incidence of the droplets is a predetermined angle greater than 0°; the landing interval between adjacent droplets on the object is less than the interval of the nozzles in the arrangement direction; and the adjacent landing droplets partially overlap each other.

[0181] Eleventh aspect

[0182] According to the eleventh aspect, a liquid discharge method includes: discharging droplets from a nozzle onto an object; and controlling the amount of a droplet and the droplet landing interval on the object based on the landing position of the droplet on the object and the angle of incidence of the droplet relative to the surface of the object, so as to discharge the droplet onto the object.

[0183] The above embodiments are illustrative and do not limit the invention. Therefore, many additional modifications and variations are possible based on the above teachings. For example, within the scope of the invention, elements and / or features of different illustrative embodiments can be combined with and / or substituted for each other. Any of the above operations can be performed in various other ways, for example, in a different order than that described above.

[0184] This patent application is based on and claims priority to Japanese Patent Application No. 2023-155831, filed with the Japan Patent Office on September 21, 2023, the entire disclosure of which is incorporated herein by reference.

[0185] List of reference numerals

[0186] 1 Discharge Unit

[0187] 2 Painting Robot

[0188] 11 First arm (moving mechanism)

[0189] 12 Second arm (moving mechanism)

[0190] 29 droplets

[0191] 90. Robotic arm (mobile mechanism)

[0192] 100 Coating equipment (liquid discharge device)

[0193] 200 objects

[0194] A. Angle of incidence

[0195] B. Inclination of the nozzle array

[0196] H Nozzle arrangement range

[0197] m Central

[0198] Landing interval in the direction of movement Px

[0199] Py is the landing interval in the orthogonal direction of movement.

[0200] S landing area

[0201] X direction of movement

[0202] Y-direction of movement orthogonal direction

[0203] List of cited references

[0204] Patent documents

[0205] [Patent Document 1] Japanese Patent No. 4792701

Claims

1. A liquid discharge device, comprising: The discharge unit includes a nozzle capable of discharging droplets toward an object; The moving mechanism causes at least one of the object and the discharging unit to move relative to each other in a relative moving direction; and The control unit is configured to control the amount of a droplet and the droplet landing interval on the object based on the landing position of a droplet in the droplet landing on the object and the angle of incidence of the droplet in the droplet relative to the surface of the object.

2. The liquid discharge device according to claim 1, in, The discharge unit includes the nozzles arranged in the arrangement direction; as well as The control unit controls the droplet landing interval by changing the tilt of the nozzle arrangement direction relative to the relative movement direction.

3. The liquid discharge device according to claim 1, in, The control unit changes the relative moving speed between the object and the discharge unit to control the landing interval of the droplets.

4. The liquid discharge device according to claim 1, in, The control unit changes the time interval at which the discharge unit discharges the droplets to control the droplet landing interval.

5. The liquid discharge device according to claim 1, in, The control unit changes the opening time or the opening amount of each nozzle to control the amount of the droplet.

6. The liquid discharge device according to claim 1, in, The control unit changes the discharge pressure of the discharge unit to discharge the droplets, thereby controlling the amount of the droplets.

7. The liquid discharge device according to claim 1, in, The control unit controls the amount of the droplet and the droplet landing interval according to the incident angle, varying them in two or more stages.

8. The liquid discharge device according to claim 1, The control unit determines the incident angle based on the center of the nozzle arrangement range.

9. The liquid discharge device according to claim 1, in, When the angle of incidence at a location of a portion of the nozzle exceeds a predetermined value, the control unit causes the discharge unit to stop discharging the droplets from that portion of the nozzle.

10. A liquid discharge device, comprising: The discharge unit includes nozzles that discharge droplets to an object, the nozzles being arranged at intervals in an arrangement direction; A moving mechanism that causes relative movement between at least one of the object and the discharge unit; and The control unit is configured as follows: When the droplet lands at the landing position of the object and the incident angle of the droplet is a predetermined angle greater than 0°, The discharge unit discharges the droplets onto the object; The landing interval between adjacent droplets on the object is controlled to be less than the interval between the nozzles in the arrangement direction; and Control the local overlap of adjacent droplets.

11. A method for discharging liquid, comprising: Discharge of droplets from a nozzle onto an object; and Based on the landing position of a droplet on the object and the angle of incidence of the droplet relative to the surface of the object, the amount of the droplet and the landing interval of the droplets on the object are controlled to discharge the droplets onto the object.

Images