Liquid discharge apparatus, liquid discharge method, and recording medium

Abstract

A liquid discharge apparatus includes: a head including a nozzle plate having nozzles arrayed in a main scanning direction, the head configured to discharge a liquid from the nozzles to coat a target surface with the liquid to perform a coating operation; a variable mechanism configured to change a position and an orientation of the head relative to the target surface; and a controller configured to: select a nozzle group from the nozzles based on: a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the liquid discharge apparatus performs the coating operation; and a relative movement speed of the head, relative to the target surface, moved by the variable mechanism.

Description

FN202501242[DESCRIPTION][Title of Invention]LIQUID DISCHARGE APPARATUS, LIQUID DISCHARGE METHOD, AND RECORDING MEDIUM[Technical Field]

[0001] The present disclosure relates to a liquid discharge apparatus, a liquid discharge method, and a recording medium.[Background Art]

[0002] The liquid discharge apparatus discharges liquid from a head to coat a coating target surface with the liquid.

[0003] For example, Patent Literature (PTL) 1 discloses a liquid discharge apparatus including a head, a movement mechanism that changes a position of the head relative to a coating target surface, and a detector that detects the position of the head relative to the coating target surface. In the liquid discharge apparatus, while the movement mechanism is causing the head to perform relative scanning along a first scanning path, the detector detects a position related to the first scanning path. Then, while the movement mechanism is causing the head to perform relative scanning along a second scanning path based on a result of detection by the detector, the head performs operation of discharging liquid onto the coating target surface.[Summary of Invention][Technical Problem]

[0004] However, in the liquid discharge apparatus of PTL 1, when the liquid discharge apparatus performs coating operation, vibration or the like generated in at least one of the head and a variable mechanism may cause coating unevenness, leading to deterioration of coating accuracy.

[0005] An object of the present disclosure is to improve coating accuracy.[Solution to Problem]

[0006] The present disclosure described herein provides a liquid discharge apparatus including: a head including a nozzle plate having nozzles arrayed in a main scanning direction, the head configured to discharge a liquid from the nozzles to coat a target surface with the liquid to perform a coating operation; a variable mechanism configured to change a position and an orientation of the head relative to the target surface; and a controller configured to: select a nozzle group from the nozzles based on: a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the liquidFN202501242discharge apparatus performs the coating operation; and a relative movement speed of the head, relative to the target surface, moved by the variable mechanism; control the head to discharge the liquid, from the nozzles of the nozzle group selected, onto the target surface to form a correction pattern on the target surface while controlling the variable mechanism to move the head relative to the target surface; acquire rotation information on rotation of the head about a rotation axis along a normal line of the nozzle plate based on the correction pattern formed on the target surface; correct the rotation of the head based on the rotation information; and control the head, the rotation of which is corrected, to discharge the liquid from the nozzles while controlling the variable mechanism to move the head relative to the target surface.The present disclosure described herein further provides a liquid discharge method including: discharging liquid from nozzles, arrayed in a main scanning direction on a nozzle plate of a head, to coat a target surface with the liquid to perform a coating operation, changing a position and an orientation of the head relative to the target surface by a variable mechanism; selecting a nozzle group from the nozzles based on: a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the coating operation is performed; and a relative movement speed of the head, relative to the target surface, moved by the variable mechanism; controlling the head to discharge the liquid, from the nozzles of the nozzle group selected, onto the target surface to form a correction pattern on the target surface while controlling the variable mechanism to move the head relative to the target surface; acquiring rotation information on rotation of the head about a rotation axis along a normal line of the nozzle plate based on the correction pattern formed on the target surface; correcting the rotation of the head based on the rotation information; and controlling the head, the rotation of which is corrected, to discharge the liquid from the nozzles while controlling the variable mechanism to move the head relative to the target surface.The present disclosure described herein further provides a recording medium storing a plurality of instructions which, when executed by one or more processors, causes the one or more processors to perform a method, including: discharging liquid from nozzles, arrayed in a main scanning direction on a nozzle plate of a head, to coat a target surface with the liquid to perform a coating operation, changing a position and an orientation of the head relative to the target surface by a variable mechanism; selecting a nozzle group from the nozzles based on: a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the coating operation is performed; and a relative movement speed of the head, relative to the target surface, moved by the variable mechanism; controlling the head to discharge the liquid, from the nozzles of the nozzle group selected, onto the target surface to form a correction pattern on the target surface while controlling the variable mechanism to move the head relative to the target surface; acquiring rotationFN202501242information on rotation of the head about a rotation axis along a normal line of the nozzle plate based on the correction pattern formed on the target surface; correcting the rotation of the head based on the rotation information; and controlling the head, the rotation of which is corrected, to discharge the liquid from the nozzles while controlling the variable mechanism to move the head relative to the target surface.[Advantageous Effects of Invention]

[0007] According to the present disclosure, coating accuracy can be improved.[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 is a schematic diagram illustrating an overall configuration of a liquid discharge apparatus according to a first embodiment.FIG. 2 is a block diagram illustrating an exemplary configuration of the liquid discharge apparatus according to the first embodiment.FIG. 3 is a diagram illustrating a configuration of a supply mechanism included in the liquid discharge apparatus according to the first embodiment.FIG. 4 is a schematic perspective view of a head included in the liquid discharge apparatus according to the first embodiment, which illustrates a configuration of the head.FIG. 5 is a schematic cross-sectional view of the head on plane V in FIG. 4.FIG. 6 is a diagram illustrating nozzles in the head included in the liquid discharge apparatus according to the first embodiment.FIG. 7 is a diagram for describing basic operation for relative movement of the head included in the liquid discharge apparatus according to the first embodiment.FIG. 8 is a timing chart for describing basic operation of liquid discharge to be performed by the head included in the liquid discharge apparatus according to the first embodiment.FIG. 9 is a block diagram illustrating a functional configuration of a controller included in the liquid discharge apparatus according to the first embodiment.FIG. 10 is a diagram illustrating coating unevenness due to head rotation during coating operation.FIG. 11 is a diagram for describing a method for correcting head rotation during coating operation by means of a correction pattern.FIG. 12 is a diagram for describing a correction error in the correction method using a correction pattern, due to head vibration during coating operation.FIG. 13 is a diagram for describing a nozzle group to be selected in the liquid discharge apparatus according to the first embodiment.FIG. 14 is a diagram illustrating a correction pattern formed by a nozzle group selected in the liquid discharge apparatus according to the first embodiment.FN202501242FIG. 15 is a flowchart illustrating operation of the liquid discharge apparatus according to the first embodiment.FIG. 16A is a diagram illustrating a state of rotation of the head caused in response to relative movement in a main scanning direction in the liquid discharge apparatus according to the first embodiment.FIG. 16B is a diagram illustrating a state of a change in an orientation of the head for correcting the rotation of the head caused in response to the relative movement in the main scanning direction in the liquid discharge apparatus according to the first embodiment.FIG. 16C is a diagram illustrating a state of correcting the rotation of the head caused in response to the relative movement in the main scanning direction in the liquid discharge apparatus according to the first embodiment.FIG. 17A is a block diagram illustrating a configuration of a liquid discharge apparatus according to a second embodiment.FIG. 17B is a schematic configuration diagram illustrating a configuration of the liquid discharge apparatus according to the second embodiment.FIG. 17C is a diagram illustrating a configuration of a medium plate.FIG. 17D is a plan view of the medium plate on which test patterns have been formed.FIG. 17E is an enlarged view of a portion P in FIG. 17D.FIG. 18 is a flowchart illustrating operation of the liquid discharge apparatus according to the second embodiment.FIG. 19 is a block diagram illustrating a functional configuration of a controller included in a liquid discharge apparatus according to a third embodiment.FIG. 20 is a diagram for describing how vibration amplitude is detected by the liquid discharge apparatus according to the third embodiment.FIG. 21 is a diagram for describing a shift of a head in a sub-scanning direction.FIG. 22 is a block diagram illustrating a functional configuration of a controller included in a liquid discharge apparatus according to a fourth embodiment.FIG. 23 is a diagram illustrating a captured image of a correction pattern in the liquid discharge apparatus according to the fourth embodiment.FIGS. 24A and 24B are schematic diagrams illustrating a configuration and disposition of an imaging unit in the liquid discharge apparatus according to the fourth embodiment.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]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 elementFN202501242includes 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.

[0009] A liquid discharge apparatus, a liquid discharge method, and a recording medium according to the present disclosure will be described below in detail with reference to the drawings.However, the following embodiments are merely examples of the liquid discharge apparatus, the liquid discharge method, and the recording medium for embodying the technical idea of the present disclosure, and the present disclosure is not limited to the following embodiments. For example, the size and positional relationship of the components illustrated in the drawings may be exaggerated for clarity of description. In the following description, the same names and the same reference signs represent the same or equivalent components, and a detailed description thereof may be omitted as appropriate.

[0010] In the embodiments, the term "along" includes a state in which an object is inclined at an angle of ±20° or less with respect to an axis. In the embodiments, the term "orthogonal" may include an error of ±10° or less with respect to 90°.

[0011] First EmbodimentExemplary Configuration of Liquid Discharge Apparatus According to First Embodiment Overall ConfigurationA configuration of a liquid discharge apparatus according to a first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram illustrating an exemplary overall configuration of a liquid discharge apparatus 100 according to the first embodiment. FIG. 2 is a block diagram illustrating an exemplary configuration of the liquid discharge apparatus 100.

[0012] The liquid discharge apparatus 100 is an apparatus that discharges liquid to coat a coating target surface with the liquid. The liquid discharged by the liquid discharge apparatus 100 adheres to the coating target surface, and is dried and sticks thereto. As a result, the coating target surface is coated. Examples of a liquid discharge method to be performed by the liquid discharge apparatus 100 include a continuous discharge method. The continuous discharge method includes a valve method, a continuous method, and the like. The valve method is a method for controlling discharge by controlling operation of a valve body to open and close a nozzle. In the continuous method, ink particles continuously discharged from a nozzle are charged, bent by means of a deflection electrode, and sprayed on a printing surface.

[0013] FN202501242For example, the coating target surface is a surface included in a vehicle body of an automobile. However, the coating target surface is not limited to the vehicle body of an automobile, and may be a surface included in a vehicle, an aircraft, a ship, or the like. In addition to an automobile, the vehicle also includes a truck, a train, and the like. The coating target surface includes a curved surface shape. The curved surface shape of the coating target surface is determined according to the design or the like of an object to be coated. However, the coating target surface may include a planar shape, or may include both a curved surface shape and a planar shape. The coating target surface may be a surface having impermeability. The impermeability refers to the property of not allowing applied liquid to permeate the surface. However, the coating target surface is not limited to a surface having impermeability, and may be a surface having permeability.

[0014] As illustrated in FIGS. 1 and 2, the liquid discharge apparatus 100 according to the present embodiment includes a head 1, a variable mechanism 2, and a controller 3. The head 1 discharges liquid. The variable mechanism 2 changes a position and an orientation of the head 1 relative to the coating target surface. The controller 3 controls operation of each of the head 1 and the variable mechanism 2. In the exemplary configurations illustrated in FIGS. 1 and 2, the liquid discharge apparatus 100 includes a supply mechanism 4 that supplies the head 1 with liquid to be discharged from the head 1. The liquid discharge apparatus 100 further includes a vibration detector 5 and an imaging unit 6. The vibration detector 5 detects vibration generated in at least one of the head 1 and the variable mechanism 2 when the liquid discharge apparatus 100 performs coating operation. The imaging unit 6 images a correction pattern formed on the coating target surface.

[0015] Under the control of the controller 3, the liquid discharge apparatus 100 drives the variable mechanism 2 that supports the head 1, based on predetermined shape data SD on the coating target surface. The liquid discharge apparatus 100 discharges liquid from the head 1 to coat the coating target surface with the liquid while changing the position and orientation of the head 1 relative to the coating target surface by driving the variable mechanism 2.

[0016] The number of heads 1 included in the liquid discharge apparatus 100 is not limited to one, and can be appropriately changed according to the size and shape of the coating target surface, the time required for coating, or the like. A configuration of the head 1 will be described in detail individually with reference to FIGS. 4 and 5.

[0017] In the exemplary configurations illustrated in FIGS. 1 and 2, the variable mechanism 2 changes the position of the head 1 relative to the coating target surface by moving the head 1. The variable mechanism 2 also changes the orientation of the head 1 relative to the coating target surface by changing an orientation of the head 1. However, the variable mechanism 2FN202501242may change the relative position by moving the coating target surface, or may change the relative orientation by changing an orientation of the coating target surface.

[0018] In the exemplary configurations illustrated in FIGS. 1 and 2, the variable mechanism 2 includes a robot arm. The variable mechanism 2 changes the relative position and relative orientation of the head 1 by driving a robot arm that supports the head 1. From the viewpoint of flexibly and accurately changing the relative position and the relative orientation, the variable mechanism 2 preferably includes a robot arm having multiple drive axes. However, the variable mechanism 2 is not limited to a variable mechanism including the robot arm, and may include a gantry mechanism, a linear motion stage, a rotation stage, or the like. The variable mechanism 2 may include a combination of two or more of a robot arm, a gantry mechanism, a linear motion stage, a rotation stage, and the like. The number of variable mechanisms 2 is not limited to one, and can be appropriately changed according to the number of heads 1. Two or more heads 1 may be supported by a single variable mechanism 2.

[0019] The variable mechanism 2 can include a position sensor such as a rotary encoder that outputs information on the relative position and relative orientation of the head 1 supported by the robot arm. The variable mechanism 2 transmits, to the controller 3, the output from the position sensor as a position signal related to the relative position and relative orientation of the head 1. The variable mechanism 2 includes position sensors equal in number to axes for changing the relative position and the relative orientation, and can transmit, to the controller 3, output from corresponding one of the position sensors for each of the multiple axes. The number of axes for the relative position in the variable mechanism 2 is, for example, three of an X-axis, a Y-axis, and a Z-axis orthogonal to each other. In addition, the number of axes for the relative orientation in the variable mechanism 2 is, for example, three of an a-axis, a [3-axis, and a y-axis. The X-axis serves as a rotation center of the a-axis. The Y-axis serves as a rotation center of the [3-axis. The Z-axis serves as a rotation center of the y-axis.

[0020] The controller 3 controls operation of each of the head 1 and the variable mechanism 2. For example, based on the predetermined shape data SD on the coating target surface, the controller 3 causes the head 1 to discharge a liquid while changing the position and orientation of the head 1 relative to the coating target surface.

[0021] As illustrated in FIG. 2, the controller 3 includes a central processing unit (CPU) 31, a read only memory (ROM) 32, and a random access memory (RAM) 33. The controller 3 also includes a hard disk drive (HDD) / solid state drive (SSD) 34, a device connection interface (VF) 35, and a communication VF 36. These components are electrically connected to each other via a system bus SB such that the components can communicate with each other.

[0022] FN202501242The CPU 31 uses the RAM 33 as a work area, and controls operation of the entire controller 3 by executing processing defined in a program stored in the ROM 32. The ROM 32 is a nonvolatile memory that stores a program for controlling, for example, operation of recording on the CPU 31, and other fixed data. The RAM 33 is a volatile memory that temporarily stores various data and the like to be used for liquid discharge by the head 1, the driving of the variable mechanism 2, and the like. The HDD / SSD 34 is a nonvolatile memory that stores, for example, the shape data SD on the coating target surface, and image data on a pattern, a character, or the like to be used when the pattern, the character, or the like is drawn on the coating target surface.

[0023] The device connection I / F 35 is an interface for communicably connecting to each of the head 1, the variable mechanism 2, and the supply mechanism 4. The communication I / F 36 is an interface for communicably connecting an external device such as a host personal computer (PC) to the controller 3.

[0024] The supply mechanism 4 operates under the control of the controller 3. A configuration of the supply mechanism 4 will be described below in detail with reference to FIG. 3.

[0025] For example, an acceleration sensor can be used as the vibration detector 5. The vibration detector 5 is disposed on at least one of the head 1 and the variable mechanism 2. The vibration detector 5 transmits a result of detecting vibration to the controller 3.

[0026] The imaging unit 6 is attached to the head 1, and images a correction pattern formed on a coating target surface S while performing relative movement along with the relative movement of the head 1 caused by the variable mechanism 2. The imaging unit 6 may capture images of multiple portions in the correction pattern to obtain multiple captured images. However, the imaging unit 6 may be disposed away from the head 1, and may perform imaging such that the correction pattern formed on the coating target surface S is included in a single captured image.

[0027] For example, a camera including a lens and an imaging element that captures an image by means of the lens can be used as the imaging unit 6. A charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), or the like can be used as the imaging element. The imaging unit 6 outputs a captured image to the controller 3.

[0028] The liquid discharge apparatus 100 can include, for example, a maintenance mechanism in addition to the components illustrated in FIGS. 1 and 2. The maintenance mechanism maintains the state of liquid discharge by the head 1. The maintenance mechanism removes thickened liquid or foreign matter adhering to a nozzle surface of the head 1 , or thickened liquid or foreign matter existing inside the head 1 by means of a wiper that wipes the nozzleFN202501242surface, a suction pump that sucks liquid from inside the head 1, or the like. By removing thickened liquid, foreign matter, or the like, the maintenance mechanism can reduce discharge anomaly of the head 1 such as non-discharge, discharge bending, or discharge speed fluctuation, and can maintain the discharge state of the head 1 in a normal state.

[0029] The liquid discharge apparatus 100 may further include, for example, a display that displays a setting screen and the like for setting conditions of liquid application by the liquid discharge apparatus 100, and an operation unit that is an operation input device such as a touch panel, a keyboard, and a mouse for receiving an operation on the liquid discharge apparatus 100.

[0030] Configuration of Supply MechanismFIG. 3 is a diagram illustrating an exemplary configuration of the supply mechanism 4.

[0031] The head 1 includes a head 1Y that discharges a yellow (Y) liquid, a head IM that discharges a magenta (M) liquid, a head 1C that discharges a cyan (C) liquid, and a head IK that discharges a black (K) liquid. The head 1 may further include a head that discharges an overcoat liquid or a head that discharges another liquid such as a head that discharges a primer liquid or a white liquid, in addition to the head that discharges the liquid of each of the colors. The supply mechanism 4 can supply the liquid of each of the colors to the head 1.

[0032] The supply mechanism 4 includes a liquid tank 330 as a sealed container that stores a liquid 325 of each of the colors to be discharged from the head 1. The liquid tanks 330 and inlets (i.e., supply ports) of the heads 1 are connected via tubes 333 such that the liquids 325 flow from the liquid tanks 330 to the heads 1 through the tubes 333.

[0033] The liquid tanks 330 are connected to a compressor 230 via pipes 331 including an air regulator 332. The compressor 230 supplies pressurized air to the liquid tanks 330. Thus, the pressurized liquid 325 of each of the colors is supplied to the inlet of the head 1, and the liquid discharge apparatus 100 discharges the liquid 325 from the nozzle of the head 1.

[0034] Configuration of HeadThe configuration of the head 1 will be described with reference to FIGS. 4 to 6. FIG. 4 is a schematic perspective view of the head 1, which illustrates an exemplary configuration of the head 1. FIG. 5 is a schematic cross-sectional view of the head 1 on plane V in FIG. 4.FIG. 6 is a schematic bottom view of the head 1, which illustrates nozzles 311 in the head 1.

[0035] In the present embodiment, the head 1 includes a nozzle plate 321, and individually discharges liquid from the nozzles 311 formed in the nozzle plate 321 and arrayed in a main scanning direction A, as illustrated in FIGS. 4 and 5. The head 1 has multiple discharge modules 340 arrayed in one or more rows in a housing 110.FN202501242

[0036] The head 1 has a supply port 111 and a collection port 112. A pressurized liquid is supplied from the outside to the discharge modules 340 through the supply port 111. The collection port 112 discharges, to the outside, liquid that has not been discharged. A connector 113 is disposed in the housing 110.

[0037] As illustrated in FIG. 5, each discharge module 340 includes the nozzle plate 321, a channel 322, and a piezoelectric element 324. The nozzle plate 321 includes the nozzle 311 that discharges liquid. The channel 322 communicates with the nozzle 311, and supplies pressurized liquid. The piezoelectric element 324 drives a needle-shaped valve body that opens and closes the nozzle 311. A nozzle surface 350 corresponds to a surface of the nozzle plate 321 in a direction in which liquid is discharged. A normal line N of the nozzle plate 321 is also a normal line N of the nozzle surface 350.

[0038] The nozzle plate 321 is joined to the housing 110. Furthermore, the channel 322 is a channel common to the multiple discharge modules 340 in the housing 110. The liquid discharge apparatus 100 supplies pressurized liquid from the supply port 111 through the channel 322, and discharges the liquid from the collection port 112. During a period in which liquid is discharged to the coating target surface, discharge of the liquid from the collection port 112 may be temporarily stopped so as not to lower the efficiency of discharging the liquid from the nozzle 311.

[0039] As illustrated in FIG. 6, the head 1 has the nozzles 311 on the nozzle surface 350 that faces the coating target surface when coating operation is performed. The head 1 can individually discharge a liquid from the nozzles 311 arrayed in the main scanning direction A. In the exemplary case illustrated in FIG. 6, the head 1 includes a nozzle row 351 including three nozzles 311 arrayed in a sub-scanning direction B orthogonal to the main scanning direction A. Nine nozzle rows 351 are arrayed in the main scanning direction A. That is, the nozzles 311 corresponds to 27 nozzles 311 in the exemplary case illustrated in FIG. 6.

[0040] The nine nozzles arrayed in the main scanning direction A are placed at an angle slightly inclined with respect to the main scanning direction A. This reduces intervals at which liquid (droplet) drops onto the coating target surface in the sub-scanning direction B. Thus, liquid (droplet) drops onto the coating target surface in the sub-scanning direction B at shorter intervals. This reduces intervals between multiple linear patterns in the sub-scanning direction B, the linear patterns being formed on the coating target surface in such a way as to correspond to the nozzles 311 when the head 1 performs relative movement in the main scanning direction A, the linear patterns each extending in the main scanning direction A. A decrease in the intervals between the multiple linear patterns in the sub- scanning direction BFN202501242makes it possible to efficiently apply liquid to the coating target surface while reducing unevenness of thickness of a liquid layer on the coating target surface.

[0041] Basic Operation of Head for Relative Movement and Liquid DischargePrior to describing a functional configuration of the controller 3, basic operation of the head 1 for relative movement and liquid discharge will be described.

[0042] FIG. 7 is a diagram for describing basic operation of moving the head 1 relative to the coating target surface S. As illustrated in FIG. 7, the variable mechanism 2 causes relative movement of the head 1 in each of the main scanning direction A and the sub-scanning direction B, and the head 1 discharges liquid onto the coating target surface S while performing so-called raster scanning.

[0043] Specifically, first, the head 1 performs relative movement to a positive side in the main scanning direction A corresponding to a direction of an arrow indicating the main scanning direction A. The head 1 starts to discharge a liquid at the timing of entering a coating target region on the coating target surface S. The head 1 continuously discharges liquid while performing relative movement to the positive side in the main scanning direction A. Thus, the head 1 forms, in the coating target region, a linear pattern LI extending in the main scanning direction A. The head 1 stops discharging liquid at the timing of exiting from the coating target region.

[0044] Subsequently, the head 1 performs relative movement by a predetermined line feed distance to a positive side in the sub-scanning direction B corresponding to a direction of an arrow indicating the sub-scanning direction B. After moving in the sub-scanning direction B by the predetermined line feed distance, the head 1 moves to a negative side in the main scanning direction A, which is a direction opposite to the positive side in the main scanning direction A. The head 1 starts to discharge a liquid at the timing of entering the coating target region on the coating target surface S. The head 1 continuously discharges liquid while performing relative movement to the negative side in the main scanning direction A. Thus, the head 1 forms, in the coating target region, a linear pattern L2 extending in the main scanning direction A. The head 1 stops discharging liquid at the timing of exiting from the coating target region.

[0045] Subsequently, the head 1 forms a linear pattern L3 while moving to the positive side in the main scanning direction A, as in the case of forming the linear pattern LI. Subsequently, the head 1 forms a linear pattern L4 while moving to the negative side in the main scanning direction A, as in the case of forming the linear pattern L2.

[0046] FN202501242The liquid discharge apparatus 100 can perform coating of the coating target surface S by repeatedly performing operation of forming multiple linear patterns L including the linear pattern LI, the linear pattern L2, the linear pattern L3, and the linear pattern L4 as described above. When the coating target surface S is a flat surface, the main scanning direction A and the sub-scanning direction B are substantially orthogonal to each other. Meanwhile, when the coating target surface S is a curved surface, the main scanning direction A and the subscanning direction B intersect at an angle deviated from a right angle according to the curvature of the curved surface.

[0047] Next, FIG. 8 is a timing chart for describing basic operation of liquid discharge to be performed by the head 1.

[0048] In FIG. 8, the variable mechanism 2 periodically transmits, to the controller 3, a position signal P related to a current position of the head 1 supported by the robot arm. The position signal related to the current position includes position information (unit: mm) in each direction of the X-axis, the Y-axis, and the Z-axis, and orientation information (unit: degree) in each direction of the a-axis, the [3-axis, and the y-axis.

[0049] The variable mechanism 2 outputs a synchronization signal T1 to the controller 3 at the timing of entering the coating target region on the coating target surface S so as to synchronize operation of the robot arm with liquid discharge operation performed by the head 1. The controller 3 generates an interval signal T2 for each interval at which liquid is to be discharged, in accordance with the position signal P received from the variable mechanism 2. In the exemplary case illustrated in FIG. 8, the controller 3 generates the interval signal T2 every time relative movement is performed by 100dpi, that is, 0.254 mm in a three-dimensional space including the X-axis, the Y-axis, and the Z-axis. The controller 3 also generates a discharge signal T3, and outputs the discharge signal T3 to the head 1. The discharge signal T3 has a discharge time of Tout after a delay time of Td triggered by the interval signal T2 The head 1 continuously discharges liquid for a period of the discharge time Tout that coincides with a period during which the discharge signal T3 is Low. The delay time Td and the discharge time Tout are variable according to the shape data SD on the coating target surface S, and the like.

[0050] Functional Configuration of ControllerThe functional configuration of the controller 3 will be described with reference to FIGS. 9 to 14. FIG. 9 is a block diagram illustrating an exemplary functional configuration of the controller 3. FIG. 10 is a diagram illustrating coating unevenness due to a single rotation of the head 1 during coating operation. FIG. 11 is a diagram for describing a method for correcting a single rotation of the head 1 during coating operation by means of a correction pattern. FIG. 12 is a diagram for describing a correction error in the correction method usingFN202501242a correction pattern, due to vibration of the head 1 during coating operation. FIG. 13 is a diagram for describing a nozzle group 360 to be selected in the liquid discharge apparatus 100. FIG. 14 is a diagram illustrating a correction pattern E formed by the nozzle group 360 selected in the liquid discharge apparatus 100. FIGS. 10 to 14 illustrate the head 1 viewed from the nozzle surface 350 side.

[0051] As illustrated in FIG. 9, the controller 3 includes an input unit 301, a nozzle group selection unit 302, a rotation information acquisition unit 303, a correction data creation unit 304, a head controller 305, a variable mechanism controller 306, a supply controller 307, and an output unit 308.

[0052] Each function of the input unit 301 and the output unit 308 is implemented by the device connection VF 35, the communication VF 36, and the like, in FIG. 2. Meanwhile, each function of the input unit 301 and the output unit 308 may be implemented by, for example, the CPU 31 loading a program stored in the ROM 32 into the RAM 33 and executing processing defined in the program. Each function of the nozzle group selection unit 302, the rotation information acquisition unit 303, the correction data creation unit 304, the head controller 305, the variable mechanism controller 306, and the supply controller 307 is implemented by, for example, the CPU 31 loading a program stored in the ROM 32 into the RAM 33 and executing processing defined in the program.

[0053] A part of each functional configuration of the controller 3 may be implemented by a device or apparatus other than the controller 3. The device other than the controller 3 refers to the head 1, the variable mechanism 2, or the like. The apparatus other than the controller 3 refers to a personal computer (PC) or the like communicably connected to the controller 3. A part of each functional configuration of the controller 3 may also be implemented by distributed processing between the controller 3 and a device or apparatus other than the controller 3.

[0054] Here, as illustrated in FIG. 10, when the liquid discharge apparatus 100 performs coating operation, the head 1 may rotate about a rotation axis RC along the normal line N of the nozzle plate 321 while being subjected to relative movement by the variable mechanism 2. As a result of rotation of the head 1 about the rotation axis RC, the position of the nozzle 311 is shifted from a desired position. As the nozzle 311 is farther away from the rotation axis RC in the main scanning direction A, a positional shift accompanying the rotation increases. The positional shift of the nozzles 311 causes uneven intervals, in the sub-scanning direction B, between the multiple linear patterns L formed on the coating target surface by the head 1 discharging liquid from each of the nozzles 311 while performing relative movement in the main scanning direction A. Since the intervals between the multiple linear patterns L in theFN202501242sub-scanning direction B become uneven, the thickness of the liquid layer formed on the coating target surface becomes uneven, leading to coating unevenness.

[0055] In order to reduce coating unevenness, for example, the liquid discharge apparatus 100 can form a correction pattern on the coating target surface before coating, and correct rotation of the head 1 based on the correction pattern. The correction pattern is multiple linear patterns extending in the main scanning direction A. The multiple linear patterns is formed by liquid discharged from a nozzle group including a predetermined nozzles 311 in the head 1 during relative movement of the head 1 in the main scanning direction A. The liquid discharge apparatus 100 can correct rotation of the head 1 by acquiring information on the rotation of the head 1 during coating operation and changing the orientation of the head 1 so as to reduce the rotation of the head 1 , based on the correction pattern formed on the coating target surface.

[0056] The nozzle group 360 and the correction pattern E formed by use of the nozzle group 360 are exemplified in FIG. 11. In the exemplary case illustrated in FIG. 11, the nozzle group 360 includes nozzles 311-1 and 311-2. The correction pattern E includes a correction pattern E 1 formed by liquid discharged from the nozzle 311-1 and a correction pattern E2 formed by liquid discharged from the nozzle 311-2.

[0057] When positions of the nozzles 311-1 and 311-2 change due to rotation of the head 1 about the rotation axis RC, an interval d in the sub-scanning direction B between the correction pattern El and the correction pattern E2 changes. The liquid discharge apparatus 100 can acquire information on the rotation of the head 1 based on the interval d. The liquid discharge apparatus 100 corrects the rotation of the head 1 by changing the orientation of the head 1 such that the rotation of the head 1 is reduced during coating operation, based on the information on the rotation of the head 1 acquired in advance by use of the correction pattern E.

[0058] From the viewpoint of acquiring the information on the rotation of the head 1 with high accuracy, the nozzles to be used as the nozzle group 360 is preferably as far as possible from the rotation axis RC of the head 1 in the main scanning direction A. For example, it is preferable to use a nozzle located most upstream and a nozzle located most downstream in the main scanning direction A among the nozzles included in the head 1.

[0059] Meanwhile, the head 1 may vibrate while performing relative movement in the main scanning direction A during coating operation. Due to this vibration, the correction pattern E includes a pattern that is displaced in the sub-scanning direction B according to the relative position in the main scanning direction A, as illustrated in FIG. 12. In the exemplary case illustrated in FIG. 12, the correction pattern E includes a sinusoidal pattern that is displaced in the sub-FN202501242scanning direction B according to the relative position in the main scanning direction A. The phase of the displacement of the correction pattern E in the sub-scanning direction B may be different for each of the nozzles 311 used as the nozzle group 360. Here, the phase of the displacement of the correction pattern E in the sub-scanning direction B refers to the phase of a pattern displaced in the sub-scanning direction B according to the relative position in the main scanning direction A.

[0060] A phase shift for each of two nozzles 311 caused by displacement in the sub-scanning direction B in the correction pattern E is exemplified in FIG. 12. The correction pattern E illustrated in FIG. 12 includes the correction pattern El and the correction pattern E2. The correction pattern El and the correction pattern E2 are correction patterns formed by liquids discharged from different nozzles 311 in the head 1. Displacement of the correction pattern El in the sub-scanning direction B is out of phase with displacement of the correction pattern E2 in the sub-scanning direction B. Due to this phase shift, the interval d between the correction pattern El and the correction pattern E2 changes according to positions in the main scanning direction A. In the exemplary case illustrated in FIG. 12, an interval dl, an interval d2, and an interval d3 are different from each other according to positions in the main scanning direction A. Since the interval d varies depending on positions in the main scanning direction A, there are cases where the interval d cannot be accurately detected and it is not possible to accurately acquire information on the rotation of the head 1 based on the interval d.

[0061] In the case of a head in which multiple nozzle rows each including nozzles arrayed in the subscanning direction B is arrayed in the main scanning direction A, a positional shift of the nozzles due to vibration of the head is often smaller than a positional shift of the nozzles due to rotation of the head. This is because, as a length in which the multiple nozzle rows is arrayed in the main scanning direction A increases, the positional shift of the nozzles due to the rotation of the head becomes larger, and the positional shift of the nozzles due to the rotation of the head becomes relatively larger than the positional shift due to vibration of the head. Therefore, coating unevenness is less affected directly by vibration of the head.However, since the interval d changes according to positions in the main scanning direction A due to vibration of the head, the information on the rotation of the head cannot be accurately acquired, and a correction error occurs. Therefore, vibration of the head indirectly affects coating unevenness as a correction error of the rotation of the head.

[0062] In the present embodiment, the controller 3 acquires information on vibration generated in at least one of the head 1 and the variable mechanism 2 when the liquid discharge apparatus 100 performs coating operation. The controller 3 selects the nozzle group 360 from the nozzles 311 based on a maximum vibration frequency component and a predetermined relative movement speed of the head 1. The maximum vibration frequency component is the largestFN202501242of multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in the vibration. The relative movement speed is the speed of relative movement of the head 1 caused by the variable mechanism 2. The controller 3 discharges liquid from the selected nozzle group 360 to form the correction pattern E on the coating target surface S. The controller 3 acquires information on the rotation of the head 1 about the rotation axis RC along the normal line N of the nozzle plate 321 based on the correction pattern E formed on the coating target surface S. The controller 3 controls liquid discharge from the head 1 by correcting the rotation of the head 1 based on the information on the rotation of the head 1, the head 1 being subjected to relative movement by the variable mechanism 2. Thus, in the present embodiment, the rotation of the head 1 can be reduced to reduce coating unevenness, and thus, coating accuracy can be improved.

[0063] For example, the controller 3 creates correction data for changing the orientation of the head 1 by means of the variable mechanism 2 for each predetermined teaching position in the main scanning direction A based on the information on the rotation of the head 1. The correction data are data for reducing rotation of the head 1 and changing the orientation of the head 1 such that the nozzles 311 arrayed in the sub-scanning direction B is placed as parallel as possible to the sub-scanning direction B, for each of multiple teaching positions in the main scanning direction A. The controller 3 can control liquid discharge from the head 1 by correcting the rotation of the head 1 by means of the correction data, the head 1 being subjected to relative movement by the variable mechanism 2.

[0064] In the exemplary configuration illustrated in FIG. 9, the input unit 301 inputs the shape data SD on the coating target surface S from an apparatus other than the controller 3 by controlling communication with the apparatus other than the controller 3. The apparatus other than the controller 3 may be, for example, a PC communicably connected to the controller 3 via a network such as the Internet, or may be a portable memory such as a universal serial bus (USB) memory. The input unit 301 passes the shape data SD to each of the head controller 305 and the variable mechanism controller 306.

[0065] In addition, the input unit 301 inputs a result of detection of vibration generated during coating operation in at least one of the head 1 and the variable mechanism 2, the vibration being detected by the vibration detector 5 in FIG. 2. The input unit 301 passes the vibration detection result to the nozzle group selection unit 302. Furthermore, the input unit 301 inputs an image of the correction pattern E captured by the imaging unit 6 in FIG. 2. The input unit 301 passes the captured image of the correction pattern to the rotation information acquisition unit 303.

[0066] The nozzle group selection unit 302 inputs, via the input unit 301, the result of vibration detection by the vibration detector 5. Based on the vibration detection result, the nozzleFN202501242group selection unit 302 determines a maximum vibration frequency component that is the largest of multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in vibration generated in at least one of the head 1 and the variable mechanism 2 when the liquid discharge apparatus 100 performs coating operation. The nozzle group selection unit 302 selects the nozzle group 360 from the nozzles 311 based on the determined maximum vibration frequency component and the predetermined relative movement speed of the head 1, which is the speed of relative movement of the head 1 caused by the variable mechanism 2.

[0067] For example, the nozzle group selection unit 302 selects the nozzle group 360 that allows alignment of phases of displacement of the correction pattern E in the sub-scanning direction B, the displacement being caused in response to relative movement of the head 1 in the main scanning direction A, the relative movement being caused by the variable mechanism 2. The nozzle group selection unit 302 passes information on the selected nozzle group 360 to the head controller 305.

[0068] Selection of the nozzle group 360 by the nozzle group selection unit 302 will be described in more detail with reference to FIG. 13. FIG. 13 illustrates nozzles 311 formed in the nozzle surface 350. Here, n is an integer. Furthermore, the symbol “f ’ denotes a maximum vibration frequency component that is the largest of multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in vibration generated in at least one of the head 1 and the variable mechanism 2 when the liquid discharge apparatus 100 performs coating operation. The symbol “v” denotes the predetermined relative movement speed of the head 1, which is the speed of relative movement of the head 1 caused by the variable mechanism 2.

[0069] The nozzle 311-1 is a nozzle included in the nozzle group 360, and is a nozzle determined in advance as a reference of distance in the main scanning direction A. The nozzle 311-2 is a nozzle located at a distance of “v / f ’ from the nozzle 311-1 in the main scanning direction A. A nozzle 311-3 is a nozzle located at a distance of “1 / 2 x v / f’ from the nozzle 311-1 in the main scanning direction A. A nozzle 311-4 is a nozzle located at a distance of “3 / 2 x v / f’ from the nozzle 311-1 in the main scanning direction A.

[0070] For example, the distance in the main scanning direction A between two nozzles 311 that allow alignment of phases of the correction pattern E formed on the coating target surface S is expressed as “(n / 2)x(v / f)”. Therefore, in the present embodiment, the nozzle group selection unit 302 selects the nozzle group 360 such that the distance between the two nozzles 311 in the main scanning direction A is expressed as “(n / 2) x (v / f)”. In practice, the distance between the nozzles 311 is not accurately set to “n x (v / f)” in many cases. Therefore, theFN202501242nozzle group selection unit 302 can select, as the nozzle group 360, two nozzles 311 at a distance closest to “n x (v / f)” from each other in the main scanning direction A.

[0071] For example, the nozzle group selection unit 302 can select, as the two nozzles 311 to be included in the nozzle group 360, the nozzle 311-1 serving as a reference and the nozzle 311-2 where n = 2, the nozzle 311-2 being substantially at a distance of “(v / f)” from the nozzle 311-1 in the main scanning direction A. However, the nozzle group selection unit 302 may select, as the two nozzles 311 to be included in the nozzle group 360, the nozzle 311-1 and either the nozzle 311-3 where n = 1 or the nozzle 311-4 where n = 3.

[0072] The controller 3 causes the head controller 305 to discharge a liquid from the nozzle group 360 selected by the nozzle group selection unit 302 while causing the variable mechanism controller 306 to perform relative movement of the head 1. As a result, the correction pattern E is formed on the coating target surface S. As a result of forming the correction pattern E by means of the nozzle group 360 selected by the nozzle group selection unit 302, phases of displacement in the sub-scanning direction B are aligned between the correction pattern El and the correction pattern E2 as illustrated in FIG. 14. This reduces a change in the interval d between the correction pattern El and the correction pattern E2 according to positions in the main scanning direction A.

[0073] In FIG. 9, the rotation information acquisition unit 303 acquires information on the rotation of the head 1 about the rotation axis RC along the normal line N of the nozzle plate 321 based on the correction pattern E formed on the coating target surface S. For example, the rotation information acquisition unit 303 inputs, via the input unit 301, the image of the correction pattern E that the imaging unit 6 has captured while being subjected to relative movement in the main scanning direction A by the variable mechanism 2. The rotation information acquisition unit 303 performs image processing on the input captured image of the correction pattern E, and detects the interval d between the correction pattern El and the correction pattern E2 in the sub-scanning direction B. The rotation information acquisition unit 303 acquires information on the rotation of the head 1 by calculation based on the interval d and a predetermined distance between the nozzles 311-1 and 311-2 of the nozzle group 360 in the main scanning direction A. The rotation information acquisition unit 303 can acquire information on the rotation of the head 1 for each relative position of the head 1 in the main scanning direction A.

[0074] As illustrated in FIG. 14, the interval d is substantially constant in the correction pattern E regardless of positions in the main scanning direction A. Therefore, the rotation information acquisition unit 303 can acquire information on the rotation of the head 1 from the interval d with high accuracy. The rotation information acquisition unit 303 passes the acquired information on the rotation of the head 1 to the correction data creation unit 304.FN202501242

[0075] In FIG. 9, the correction data creation unit 304 creates correction data based on the information on the rotation of the head 1. The correction data creation unit 304 can create correction data based on the interval d for each predetermined teaching position in the main scanning direction A. The correction data creation unit 304 passes the created correction data to the variable mechanism controller 306.

[0076] The head controller 305 controls discharge of liquid from the head 1 by outputting head control information via the output unit 308. The head control information is information for controlling discharge of liquid by the head 1. The head controller 305 can control the timing of liquid discharge from the nozzle 311, the amount of liquid, discharge frequency, and the like.

[0077] The variable mechanism controller 306 controls the position and orientation of the head 1 relative to the coating target surface S by means of the variable mechanism 2, by outputting variable mechanism control information via the output unit 308. The variable mechanism control information is information for controlling operation of the variable mechanism 2.

[0078] In the present embodiment, the variable mechanism controller 306 controls liquid discharge from the head 1 by correcting the rotation of the head 1 by means of correction data, the head 1 being subjected to relative movement by the variable mechanism 2. Specifically, the variable mechanism controller 306 changes the orientation of the head 1 subjected to relative movement by the variable mechanism 2, by using correction data for correcting the rotation of the head 1 for each position of the head 1 in the main scanning direction A. The head controller 305 causes liquid to be discharged from the head 1 subjected to relative movement by the variable mechanism 2.

[0079] The supply controller 307 controls supply of liquid from the supply mechanism 4 to the head 1 by outputting supply control information via the output unit. The supply control information is information for controlling liquid supply by the supply mechanism 4.

[0080] The output unit 308 outputs each of the head control information, the variable mechanism control information, and the supply control information by controlling communication with each of the head 1, the variable mechanism 2, and the supply mechanism 4.

[0081] The controller 3 may be divided into a robot control panel that controls operation of the variable mechanism 2, a discharge control device that controls discharge of liquid by the head 1, and a PC that controls the entire operation. For example, the robot control panel has functions of the nozzle group selection unit 302, the rotation information acquisition unit 303, the correction data creation unit 304, and the variable mechanism controller 306 in FIG. 9.FN202501242The discharge control device has functions of the head controller 305 and the supply controller 307 in FIG. 9. The PC has a function of integrally controlling the robot control panel and the discharge control device.

[0082] The robot control panel and the discharge control device are connected to each other in a wired or wireless manner such that information held by the robot control panel can be output to the discharge control device. The PC generates a robot program for controlling the robot control panel, and transmits the robot program to the robot control panel before coating. Furthermore, the PC generates coating data for controlling the discharge control device, and transmits the coating data to the discharge control device before coating. The coating data may include the correction data created by the correction data creation unit 304. When the PC detects the start of coating performed in response to an operation input or the like by an operator, the PC instructs the robot control panel to start executing the robot program. The liquid discharge apparatus 100 can perform coating of the coating target surface S by controlling liquid discharge from the head 1 by means of the discharge control device in synchronization with operation of the variable mechanism 2 as a robot.

[0083] A programming language for robots is developed by each robot manufacturer. An operator of a robot can create a program suitable for the robot to be used. One example of a robot programming language to be input to the robot control panel is described below.MOVJ X=100 Y=50 Z=0 a=0 P=45 y=30 This command is for moving the head 1 to X=100 Y=50 Z=0 in each axis operation. Here, a, P, and y represent angles of the head 1.MOVL X=200 Y=80 Z=11 a=0 P=30 y=0 This command is for moving the head 1 to X=200 Y=80 Z=11 by linear interpolation. Here, a, P, and y represent angles of the head 1.

[0084] Operation of Liquid Discharge Apparatus According to First EmbodimentFIG. 15 is a flowchart illustrating operation of the liquid discharge apparatus 100. FIG. 15 illustrates exemplary operation of creating correction data to be performed by the liquid discharge apparatus 100. In the exemplary case illustrated in FIG. 15, the liquid discharge apparatus 100 starts the operation of FIG. 15 on the condition that an operation of starting the operation of creating correction data has been received from an operator of the liquid discharge apparatus 100 via the operation unit.

[0085] First, in step Sil, the liquid discharge apparatus 100 causes the vibration detector 5 to detect the vibration frequency of the head 1 during coating operation. The liquid discharge apparatus 100 causes the variable mechanism 2 to perform relative movement of the head 1 in the same manner as when causing the variable mechanism 2 to perform relative movement of the head 1 during coating operation, and detects vibration of the head 1 during the relative movement. The vibration detector 5 sequentially or collectively outputs detection results toFN202501242the controller 3. The liquid discharge apparatus 100 returns the head 1 to an initial position after the vibration detector 5 completes detection of vibration.

[0086] Subsequently, in step S12, the liquid discharge apparatus 100 causes the nozzle group selection unit 302 to select the nozzle group 360 to be used for forming the correction pattern E from the nozzles 311 of the head 1. The nozzle group selection unit 302 passes information on the selected nozzle group 360 to the head controller 305.

[0087] Subsequently, in step S13, the liquid discharge apparatus 100 causes liquid to be discharged from the nozzle group 360 selected by the nozzle group selection unit 302 while causing the variable mechanism 2 to perform relative movement of the head 1 in the main scanning direction A. As a result, the correction pattern E is formed on the coating target surface S.

[0088] Subsequently, in step S14, the liquid discharge apparatus 100 causes the imaging unit 6 to image the correction pattern E while causing the variable mechanism 2 to perform relative movement of the imaging unit 6 in the main scanning direction A.

[0089] Step S 13 and step S 14 may be executed in parallel. That is, liquid discharge from the head 1 and the imaging of the correction pattern E by the imaging unit 6 may be performed in parallel. For example, the liquid discharge apparatus 100 may discharge a liquid from the head 1 to form the correction pattern E on the coating target surface S while causing the variable mechanism 2 to perform relative movement of each of the head 1 and the imaging unit 6 in the main scanning direction A, and may also cause the imaging unit 6 to image the correction pattern E formed on the coating target surface S.

[0090] From the viewpoint of reducing the number of times relative movement of the head 1 and the imaging unit 6 is performed in the main scanning direction A, liquid discharge from the head 1 and the imaging of the correction pattern E by the imaging unit 6 are preferably performed in parallel. The imaging unit 6 passes the captured image of the correction pattern E to the rotation information acquisition unit 303.

[0091] Subsequently, in step S15, the liquid discharge apparatus 100 causes the rotation information acquisition unit 303 to acquire information on rotation of the head 1 about the rotation axis RC along the normal line N of the nozzle plate 321 for each predetermined teaching position in the main scanning direction A based on the image of the correction pattern E captured by the imaging unit 6. The rotation information acquisition unit 303 passes the acquired information on the rotation of the head 1 to the correction data creation unit 304.

[0092] Subsequently, in step S16, the liquid discharge apparatus 100 causes the correction data creation unit 304 to create correction data on the basis of the information on the rotation of theFN202501242head 1 acquired by the rotation information acquisition unit 303. The correction data creation unit 304 passes the created correction data to the variable mechanism controller 306.

[0093] Subsequently, in step S17, the liquid discharge apparatus 100 performs coating while performing correction by using the correction data, so as to verify whether correction using the correction data reduces coating unevenness.

[0094] Subsequently, in step S18, the liquid discharge apparatus 100 determines whether coating unevenness has been reduced. For example, the operator of the liquid discharge apparatus 100 visually recognizes a result of coating performed in step S17, and determines whether coating unevenness has been reduced. The liquid discharge apparatus 100 determines whether coating unevenness has been reduced, by receiving a determination result from the operator via the operation unit.

[0095] In a case where it is determined in step S18 that coating unevenness has not been reduced (step S18, NO), the liquid discharge apparatus 100 performs operation in and after step Sil again, and repeats the operation until it is determined in step S18 that coating unevenness has been reduced. Meanwhile, when it is determined in step S18 that coating unevenness has been reduced (YES in step S18), the liquid discharge apparatus 100 terminates the operation.

[0096] As described above, the liquid discharge apparatus 100 can create correction data.

[0097] A description will be given of the timing at which the operation (hereinafter, referred to as "rotational orientation difference correction") of the liquid discharge apparatus 100 illustrated in FIG. 15 is performed, that is, what triggers the operation of the liquid discharge apparatus 100 illustrated in FIG. 15.

[0098] The operation "rotational orientation difference correction" is performed during preparation for coating. The preparation for coating refers to preparation operation to be performed before so-called "main coating" individually from the main coating in which coating operation is repeatedly performed on a large number of objects to be coated so as to be made into finished products in a production line or the like. In preparation for coating, first, a coating target is selected, and then methods for controlling the variable mechanism, the head, and the supply mechanism are determined according to the coating target. These control methods are designed according to specifications of the variable mechanism, the head, and the supply mechanism, and are mainly performed on the desk. Next, the determined control methods are implemented on the actual machine, and it is confirmed that desired operation is implemented while the difference between the desktop simulation and the actual machine is confirmed, and adjustment is performed as necessary. The operation "rotational orientation difference correction" is also one of the checking and adjusting operation steps. Next, testFN202501242coating and quality confirmation are performed, and when it is confirmed that desired coating has been finished, the coating operation is completed. Here, when the desired coating has not been finished, the control method and the like are reviewed again.

[0099] As a result of performing the preparation for coating, the coating operation is completed. In the main coating, the coating operation completed in the preparation for coating is repeatedly executed. At that time, the adjusting operation and the control method are not examined, and basically, the coating operation is repeatedly performed. That is, the rotational orientation difference correction is performed during the preparation for coating to be performed before the main coating, and is not performed every time the main coating is performed.

[0100] It is known that, in the coating operation determined by the preparation for coating, an error gradually occurs in the variable mechanism, the head, or the supply mechanism itself, or control thereof due to repeated execution of coating operation and the lapse of time.Therefore, depending on a coating target and frequency, it is necessary to perform a specific process of preparation for coating again once in a certain period of time, for example, once in several months. The same applies to the rotational orientation difference correction, and for example, it is necessary to perform the rotational orientation difference correction at a frequency of about once in several months.

[0101] A state in which rotation of the head 1 caused in response to relative movement in the main scanning direction A is corrected in the liquid discharge apparatus 100 will be described with reference to FIGS. 16A to 16C. FIG. 16A is a diagram illustrating the state of rotation of the head 1 caused in response to relative movement in the main scanning direction A in the liquid discharge apparatus 100. FIG. 16B is a diagram illustrating the state of a change in the orientation of the head for correcting rotation of the head 1 caused in response to the relative movement in the main scanning direction A in the liquid discharge apparatus 100. FIG. 16C is a diagram illustrating the state of correcting the rotation of the head 1 caused in response to the relative movement in the main scanning direction A in the liquid discharge apparatus 100. FIGS. 16A to 16C illustrate the head 1 viewed from the nozzle surface 350 side.

[0102] As illustrated in FIG. 16A, when the variable mechanism 2 moves the head 1 in the main scanning direction A, the head 1 rotates about the rotation axis RC. The head 1 discharges liquid from the nozzle group 360 selected by the nozzle group selection unit 302, to form the correction pattern E. The liquid discharge apparatus 100 obtains a rotation angle 91 by using the interval d ideal for the correction pattern E determined in advance and the interval dl of a detection result. Furthermore, the liquid discharge apparatus 100 obtains a rotation angle 92 by using the ideal interval d and the interval d2 of the detection result.

[0103] FN202501242As illustrated in FIG. 16B, the liquid discharge apparatus 100 creates correction data for changing the orientation of the head 1 such that the rotation angle 91 and the rotation angle 92 decrease at each predetermined teaching position in the main scanning direction A. For example, the correction data are data for changing the orientation of the head 1 such that the head 1 rotates by an angle of -91 at a teaching position where the head 1 rotates by the rotation angle 91. The correction data are also data for changing the orientation of the head 1 such that the head 1 rotates by an angle of -92 at a teaching position where the head 1 rotates by the rotation angle 92.

[0104] For example, the rotation angle 91 and the rotation angle 92 of the head 1 decrease, as illustrated in FIG. 16C, as a result of changing the orientation of the head 1 according to the correction data. In FIG. 16C, a head 1W indicated by a broken line represents the head 1 in a state where the orientation thereof has yet to be changed and in a state of being rotated.

[0105] Operation and Effect of Liquid Discharge Apparatus According to First Embodiment As described above, in the present embodiment, the controller 3 forms the correction pattern E on the coating target surface S by using the nozzle group 360 selected from the nozzles 311 based on the maximum vibration frequency component f and the predetermined relative movement speed v of the head 1. The maximum vibration frequency component f is the largest of multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in vibration generated in at least one of the head 1 and the variable mechanism 2 when the liquid discharge apparatus 100 performs coating operation. The relative movement speed v is the speed of relative movement of the head 1 caused by the variable mechanism 2.

[0106] The controller 3 acquires information on the rotation of the head 1 about the rotation axis RC along the normal line N of the nozzle plate 321 based on the correction pattern E formed on the coating target surface S. The controller 3 controls liquid discharge from the head 1 by correcting rotation of the head 1 subjected to relative movement by the variable mechanism 2, on the basis of the information on the rotation. Selection of the nozzle group 360 makes it possible to reduce the influence of vibration of the head 1, and to accurately correct the rotation of the head 1. As a result, the coating accuracy can be improved in the present embodiment.

[0107] The liquid discharge apparatus 100 includes the vibration detector 5. The controller 3 selects the nozzle group 360 based on the maximum vibration frequency component f and the predetermined relative movement speed v of the head 1. The maximum vibration frequency component f is the largest of multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in vibration detected by the vibration detector 5. The relative movement speed v is the speed of relativeFN202501242movement of the head 1 caused by the variable mechanism 2. Use of a result of detection by the vibration detector 5 enables appropriate selection of the nozzle group 360 for reducing the influence of vibration of at least one of the head 1 and the variable mechanism 2.

[0108] The controller 3 selects the nozzle group 360 that allows alignment of phases of the displacement of the correction pattern E in the sub-scanning direction B, the displacement being caused in response to the relative movement of the head 1 in the main scanning direction A. As a result, the liquid discharge apparatus 100 can reduce the influence of vibration of at least one of the head 1 and the variable mechanism 2 and accurately correct rotation of the head 1 caused in response to the relative movement in the main scanning direction A.

[0109] For example, the controller 3 forms the correction pattern E on the coating target surface S by using the nozzle group 360 selected such that the distance between the nozzles 311 in the main scanning direction A is expressed as “(n / 2) x (v / f)”. The controller 3 changes the orientation of the head 1 by means of the variable mechanism 2 at each predetermined teaching position in the main scanning direction A based on the correction pattern E. As a result, the liquid discharge apparatus 100 can reduce the influence of vibration of at least one of the head 1 and the variable mechanism 2 and accurately correct rotation of the head 1 caused in response to the relative movement in the main scanning direction A.

[0110] Second EmbodimentNext, a liquid discharge apparatus according to a second embodiment will be described. In the following description, the same names and reference signs as those described above represent the same or equivalent components, and a detailed description thereof may be omitted as appropriate. The same applies to a liquid discharge apparatus to be described below.

[0111] Configuration of Liquid Discharge Apparatus According to Second EmbodimentFIG. 17A is a block diagram illustrating a configuration of a liquid discharge apparatus 100a according to the second embodiment.

[0112] In the present embodiment, the liquid discharge apparatus 100a includes a bend detector 7 that detects the amount of bend of liquid discharged from the head 1, as illustrated in FIG. 17A. The controller 3 further corrects the rotation of the head 1 subjected to relative movement by the variable mechanism 2, based on the amount of bend detected by the bend detector 7. The liquid discharge apparatus 100a is different from the liquid discharge apparatus 100 according to the first embodiment in this respect.

[0113] FN202501242For example, the method described in Japanese Unexamined Patent Application Publication No. 2024-92320 can be used by the bend detector 7 for detecting discharge bending. In the method described in Japanese Unexamined Patent Application Publication No. 2024-92320, liquid is discharged onto a predetermined medium, the liquid applied to the medium is imaged by a camera, and discharge bending is detected based on the position and size of the liquid. Details disclosed in Japanese Unexamined Patent Application Publication No. 2024-92320 are incorporated herein by reference. Hereinafter, a coating system 10000 will be described as an example of the liquid discharge apparatus according to the second embodiment in accordance with the description of Japanese Unexamined Patent Application Publication No.2024-92320.

[0114] FIG. 17B is a schematic configuration diagram illustrating a configuration of the coating system 10000. The coating system 10000 includes a maintenance station 2000 within the reach of a coating robot 1000. The maintenance station 2000 includes a maintenance and cleaning unit 2001. A head 1 is moved to the maintenance and cleaning unit 2001 by the coating robot 1000 before coating is performed, at the end of coating, or when coating time has exceeded a prescribed time.

[0115] The maintenance and cleaning unit 2001 includes, for example, a cleaning mechanism and a maintenance device such as a container (dummy discharge receiver). The cleaning mechanism wipes and cleans a nozzle surface of the head 1. The container is for receiving coating material discharged from a nozzle when dummy discharge is performed on the head 1.

[0116] In addition, the maintenance and cleaning unit 2001 includes a medium plate that holds a test pattern formed as a result of discharge operation performed by all nozzles of the head 1 before coating is performed or when coating time has exceeded the prescribed time. The medium plate will be described below.

[0117] The maintenance and cleaning unit 2001 includes a cleaning device that sprays cleaning liquid or cleaning air to the nozzle surface of the head 1 to clean the nozzle surface. The maintenance and cleaning unit 2001 also includes a cleaning device that sprays cleaning liquid or cleaning air to the medium plate to remove the test pattern from the medium plate.

[0118] In the present embodiment, the coating system 10000 has a configuration in which a single coating robot 1000 is installed on each side of a vehicle body U, but the configuration of the coating system 10000 is not limited thereto. The number of coating robots may be appropriately determined in consideration of a coating area of the vehicle body U, work efficiency, and the like. The coating system 10000 may include a single coating robot, or may include three or more coating robots.

[0119] FN202501242In addition, in a case where there is multiple coating robots 1000, the maintenance station 2000 may be shared by the multiple coating robots, or may be installed for each coating robot. The maintenance station 2000 is installed at a position away from the vehicle body U so that the coating material discharged from the nozzle by the above-described dummy discharge, the cleaning liquid sprayed at the time of cleaning the nozzle surface and the medium plate, and the like do not adhere to the vehicle body U.

[0120] Exemplary Configuration of Medium PlateFIG. 17C is a diagram illustrating a configuration of the medium plate. The maintenance and cleaning unit 2001 of the maintenance station 2000 includes a medium plate 2002 that holds a test pattern formed as a result of discharge operation performed by all the nozzles before coating is performed or when coating time has exceeded the prescribed time.

[0121] The medium plate 2002 is secured to a medium plate supporting member 2003 with a screw or the like. A base plate 2005 is secured to a frame 2004 of the maintenance station 2000. A cover member 2006 is attached to the frame 2004 via the base plate 2005. The medium plate supporting member 2003 on which the medium plate 2002 has been placed can reciprocate in a direction of arrow B. The medium plate supporting member 2003 can pass through the inside of the cover member 2006, and can be pulled out to the rear side of the base plate 2005. A cleaning mechanism for removing the test pattern formed on a surface of the medium plate 2002 is provided on the rear side of the base plate 2005.

[0122] The medium plate supporting member 2003 with the medium plate 2002 placed thereon, the test pattern having been removed from the medium plate 2002, passes through the inside of the cover member 2006, and moves to the front side of the base plate 2005 in accordance with formation of the next test pattern. When a test pattern is formed on the medium plate 2002, the head 1 (700, 700A, 700B) is positioned directly above the medium plate 2002 as indicated by broken lines, and discharge operation is executed by all the nozzles in this state.

[0123] In the above description, the medium plate 2002 is provided in the maintenance station 2000, but the medium plate 2002 may be installed at a location different from the maintenance station 2000.

[0124] Outline of Test PatternFIGS. 17D and 17E are explanatory diagrams illustrating exemplary test patterns. FIG. 17D is a plan view of an exemplary medium plate on which test patterns have been formed. FIG.17E is an enlarged view of a portion Pl in FIG. 17D.

[0125] FIG. 17D illustrates test patterns formed on the medium plate 2002 by multiple nozzle heads. In the case of obtaining these test patterns, the heads are moved by the coating robot so thatFN202501242nozzle surfaces of the multiple nozzle heads face the medium plate 2002, and discharge operation is executed by all the nozzles of the multiple nozzle heads. When all the nozzles of the multiple nozzle heads are normal, a test pattern TPA is obtained as illustrated in FIG.17D.

[0126] Next, a head holding member is rotated by 90 degrees by the coating robot to cause the nozzle surfaces of the multiple nozzle heads to face a region of the medium plate 2002 where the test pattern TPA has not been formed. Next, discharge operation is executed by all the nozzles of the multiple nozzle heads. When all the nozzles of the multiple nozzle heads are normal, a test pattern TPB is obtained as illustrated in FIGS. 17D and 17E.

[0127] Operation of Liquid Discharge apparatus According to Second EmbodimentFIG. 18 is a flowchart illustrating operation of the liquid discharge apparatus 100a.Redundant description of points that the liquid discharge apparatus 100a has in common with the liquid discharge apparatus 100 according to the first embodiment illustrated in FIG. 15 will be omitted, and only differences will be described. For example, the step S21 of FIG.18 relates to the step Sil of FIG. 15, the step S22 of FIG. 18 relates to the step S12 of FIG.15, the step S24 of FIG. 18 relates to the step S13 of FIG, 15, the step S25 of FIG. 18 relates to the step S14 of FIG. 15, and the step S26 of FIG. 18 relates to the step S15, and the step S28 of FIG. 18 relates to the step S17 of FIG. 15, and the step S29 of FIG. 18 relates to the step S 18 of FIG. 15.

[0128] In step S23, the liquid discharge apparatus 100a causes the bend detector 7 to detect the amount of bend of liquid discharged from the head 1, as illustrated in FIG. 18. The bend detector 7 outputs, to the controller 3, a result of detection of the amount of bend.

[0129] In step S27, the liquid discharge apparatus 100a causes the correction data creation unit 304 to create correction data for changing the orientation of the head 1 so as to reduce rotation of the head 1 subjected to relative movement by the variable mechanism 2, on the basis of the amount of bend detected by the bend detector 7. Changing the orientation of the head 1 by using the created correction data allows the liquid discharge apparatus 100a to reduce the rotation of the head 1 caused in response to relative movement in the main scanning direction A.

[0130] The timing at which operation of the liquid discharge apparatus 100 illustrated in FIG. 18 is performed, that is, what triggers the operation of the liquid discharge apparatus 100 illustrated in FIG. 18 is the same as the timing at which operation of the liquid discharge apparatus 100 illustrated in FIG. 15 is performed, that is, what triggers the operation of the liquid discharge apparatus 100 illustrated in FIG. 15.

[0131] FN202501242Operation and Effect of Liquid Discharge apparatus According to Second Embodiment For example, if the direction of liquid discharged from the head 1 deviates from a predetermined direction, the correction pattern E cannot be accurately formed, and appropriate correction data may not be created. In the present embodiment, the bend detector 7 detects the amount of bend of liquid discharged from the head 1, and creates correction data in consideration of the detected amount of bend. As a result, it is possible to reduce the influence of bending of discharged liquid and create appropriate correction data. In the present embodiment, it is possible to improve coating accuracy by correcting the rotation of the head 1 by means of appropriate correction data. Operation and effect other than those described above in the present embodiment are the same as the operation and effect in the first embodiment.

[0132] Third EmbodimentNext, a liquid discharge apparatus according to a third embodiment will be described with reference to FIGS. 19 and 20. FIG. 19 is a block diagram illustrating a functional configuration of the controller 3 included in a liquid discharge apparatus 100b according to the third embodiment. FIG. 20 is a diagram for describing how vibration amplitude is detected by the liquid discharge apparatus 100b. FIG. 20 illustrates the head 1 viewed from the nozzle surface 350 side.

[0133] As illustrated in FIG. 19, the liquid discharge apparatus 100b according to the present embodiment is different from the liquid discharge apparatus 100 according to the first embodiment in that the controller 3 includes an amplitude information acquisition unit 309. The amplitude information acquisition unit 309 detects the amplitude of displacement of the correction pattern E in the sub-scanning direction B, the displacement being caused in response to relative movement of the head 1 in the main scanning direction A, the relative movement being caused by the variable mechanism 2.

[0134] The amplitude information acquisition unit 309 acquires information on the amplitude of displacement of the correction pattern E in the sub-scanning direction B based on the correction pattern E formed by liquid discharged from each of the two nozzles 311 included in the nozzle group 360.

[0135] The controller 3 forms the correction pattern E on the coating target surface S by using the nozzle group 360 selected such that the distance between the nozzles 311 in the main scanning direction A is expressed as “{(2n - l) / 2} x (v / f)”. The controller 3 creates correction data based on the interval d between the correction patterns E in the sub-scanning direction B for each predetermined teaching position in the main scanning direction A.

[0136] FN202501242For example, the liquid discharge apparatus 100 selects the nozzle group 360 such that the distance becomes closest to (n / 2) x (v / f) in addition to consideration of the distance between the nozzles 311 in the main scanning direction A, the distance allowing displacement of the correction pattern E in the sub-scanning direction B to be in the same phase. As a result, displacement of the correction pattern E in the sub-scanning direction B between the correction pattern El and the correction pattern E2 is in the same phase or in the opposite phase.

[0137] As illustrated in FIG. 20, the correction pattern E includes the correction pattern El and the correction pattern E2 formed by the two nozzles 311 included in the nozzle group 360. In the exemplary case illustrated in FIG. 20, the phase of displacement of the correction pattern El in the sub-scanning direction B is shifted by a half cycle from the phase of displacement of the correction pattern E2 in the sub-scanning direction B. Thus, the phase of the displacement of the correction pattern El and the phase of the displacement of the correction pattern E2 are opposite to each other.

[0138] Here, a minimum interval dmin is defined as a minimum interval between the correction pattern El and the correction pattern E2 in the sub-scanning direction B, and a maximum interval dmax is defined as a maximum interval between the correction pattern El and the correction pattern E2 in the sub- scanning direction B. The amplitude information acquisition unit 309 can obtain an amplitude G of displacement of the correction pattern E in the sub- scanning direction B by calculation from the following formula.G = (dmax - dmin) / 4

[0139] Operation and Effect of Liquid Discharge apparatus According to Third Embodiment In the present embodiment, the amplitude G obtained by the amplitude information acquisition unit 309 can be used to, for example, verify vibration reducing effect in the liquid discharge apparatus 100b. Specifically, the smaller the amplitude G, the greater the vibration reducing effect in the liquid discharge apparatus 100b. Therefore, in the liquid discharge apparatus 100b, for example, it is possible to verify the vibration reducing effect by determining whether the amplitude G obtained by the amplitude information acquisition unit 309 is smaller than a predetermined amplitude threshold.

[0140] The controller 3 can also calculate a shift of the nozzle 311 due to rotation of the head 1 by calculating (dmax + dmin) / 2. Operation and effect other than those described above in the present embodiment are the same as the operation and effect in the first embodiment.

[0141] Fourth EmbodimentNext, a liquid discharge apparatus according to a fourth embodiment will be described.

[0142] FN202501242A liquid discharge apparatus according to the present embodiment is different from the liquid discharge apparatus 100b according to the third embodiment in that the controller 3 acquires information on a shift of the head 1 in the sub-scanning direction B caused in response to relative movement in the main scanning direction A, based on the correction pattern E formed by liquid discharged from each of the two nozzles 311 included in the nozzle group 360.

[0143] FIG. 21 is a diagram for describing a shift of the head 1 in the sub-scanning direction B. In FIG. 21, an ideal path IP represents an ideal relative movement path of the head 1 in the main scanning direction A. A teaching position TP represents a point for teaching the variable mechanism 2 a position where the head 1 passes in the main scanning direction A. FIG. 21 illustrates the head 1 viewed from the nozzle surface 350 side.

[0144] In the exemplary case illustrated in FIG. 21, the head 1 is shifted in the sub-scanning direction B while moving in the main scanning direction A. In addition, the head 1 is not rotating about the rotation axis RC. The head 1 meanders in relative movement in the main scanning direction A by shifting in the sub- scanning direction B in response to the relative movement in the main scanning direction A. A meandering path SP represents a path in which the head 1 meanders and performs relative movement due to the shift in the sub-scanning direction B.

[0145] Here, a description will be given of a difference between the case where the head 1 vibrates during relative movement in the main scanning direction A as described with reference to FIG. 12 and the case where the head 1 meanders during relative movement in the main scanning direction A as in the meandering path SP illustrated in FIG. 21. The vibration to be generated during the relative movement of the head 1 in the main scanning direction A refers to periodic and repeated displacement of the head 1 to be performed multiple times in the subscanning direction between the start and end of a single relative movement in the main scanning direction A. Meanwhile, meandering during the relative movement of the head 1 in the main scanning direction A refers to non-periodic displacement of the head 1 to be performed about once in the sub-scanning direction between the start and end of a single relative movement in the main scanning direction A.

[0146] FIG. 22 is a block diagram illustrating a functional configuration of the controller 3 included in the liquid discharge apparatus according to the fourth embodiment. The controller 3 includes a shift information acquisition unit 310. The controller 3 is different from the controller 3 included in the liquid discharge apparatus 100 according to the first embodiment in this respect.

[0147] The shift information acquisition unit 310 acquires information on the shift of the head 1 in the sub-scanning direction B caused in response to the relative movement in the main scanning direction A, based on the correction pattern E formed by liquid discharged fromFN202501242each of the two nozzles 311 included in the nozzle group 360. The shift information acquisition unit 310 passes the acquired information on the shift to the correction data creation unit 304.

[0148] FIG. 23 is a diagram illustrating a captured image Im of the correction pattern E in the liquid discharge apparatus according to the fourth embodiment. FIG. 23 illustrates the captured image Im obtained by the imaging unit 6 illustrated in FIG. 2 imaging the correction pattern E formed on the coating target surface. For example, the shift information acquisition unit 310 can acquire the captured image Im as information on the shift and pass the captured image Im to the correction data creation unit 304.

[0149] In the exemplary case illustrated in FIG. 23, the correction pattern E includes the correction pattern El formed by liquid discharged from one of the two nozzles 311 included in the nozzle group 360 and the correction pattern E2 formed by liquid discharged from the other.

[0150] As a procedure, first, a detection pattern is printed during continuous operation performed as usual. Next, a step operation of sequentially stopping at each teaching point is performed, and the position of the detection pattern is measured by means of the imaging unit 6, various sensors, or the like attached to the head 1, in a state where the head 1 has reached each teaching point. FIGS. 24A and 24B are schematic diagrams illustrating a configuration and disposition of the imaging unit 6. FIGS. 24A and 24B illustrate a configuration of the imaging unit 6, and disposition of the imaging unit 6 at the time of coating (see FIG. 24A) and at the time of measurement (see FIG. 24B).

[0151] It is desirable to perform measurement at a point where the head 1 is located during the step operation performed at the same teaching point as coating operation. In a case where it is difficult to image the detection pattern in the same operation due to the imaging ranges of the sensors and the imaging unit 6, or due to convenience for attachment, it is possible to choose a method for performing imaging after moving the head to teaching points used at the time of measurement, which are points collectively shifted by a certain amount (same direction, same amount) from teaching points used at the time of coating as illustrated in FIG.S 24A and 24B.

[0152] In the present embodiment, the distance in the main scanning direction A between the two nozzles 311 included in the nozzle group 360 is expressed as “(2n - l) / 2) x (v / f)”. As a result, the phases of the displacement in the sub-scanning direction B caused in response to the relative movement of the head 1 in the main scanning direction A for the correction pattern El and the correction pattern E2 are opposite to each other. The maximum interval dmax is a maximum interval between the correction pattern El and the correction pattern E2 in the sub-scanning direction B. The minimum interval dmin is a minimum interval between the correction pattern El and the correction pattern E2 in the sub- scanning direction B. AFN202501242center line CL is a line passing through the center of the above-described displacement in the correction pattern El.

[0153] The correction data creation unit 304 can create the correction data in such a way as to correct the shift of the head 1 in the sub-scanning direction B caused in response to the relative movement in the main scanning direction A. For example, in order to reduce a shift of the head 1, the correction data creation unit 304 creates correction data in such a way as to cause relative movement of the head 1 in a direction opposite to the direction of the shift by a relative movement amount substantially equal to the amount of the shift, for each teaching position TP. Based on the correction data, the liquid discharge apparatus according to the fourth embodiment causes relative movement of the head 1 in the direction opposite to the direction of the shift by the relative movement amount substantially equal to the amount of the shift, for each teaching position TP. As a result, the shift of the head 1 can be corrected, and relative movement of the head 1 can be performed in a path close to the ideal path IP illustrated in FIG. 21. Thus, in the present embodiment, coating unevenness can be reduced, and coating accuracy can be improved. Operation and effect other than those described above in the present embodiment are the same as the operation and effect in the first embodiment.

[0154] Simulation Method Using Big DataIt is possible to generate new value in various fields by analyzing big data, which are enormous amounts of data that cannot be handled by a conventional database. Advantages of utilizing big data include more accurate decision making, discovery of new business opportunities, improvement of operation efficiency, and improvement of customer satisfaction. Performing simulation by means of big data makes it possible to more accurately predict a phenomenon that has been difficult to predict, and to analyze the behavior of a complicated system in detail. The coating operation and performance of the liquid discharge apparatus according to each of the first to fourth embodiments can be simulated by means of big data. Hereinafter, a description will be given of an example of a method for performing simulation based on big data such as shape data and correction data in each embodiment.

[0155] (1) Data Collection and PreprocessingData collection is performed after a data source from which necessary data can be collected is determined. As preprocessing of the collected data, data cleaning (removal of missing value, outlier, noise, and the like) is performed. Data cleaning makes it possible to improve the quality of the data, to unify the format of the data and convert the format into a format that is easy to analyze, and to extract and create a feature amount effective for analysis. At this time, it is also possible to extract deeper features from data by using artificial intelligence (Al) technology for machine learning, deep learning, or the like.FN202501242

[0156] (2) Model SelectionAn appropriate model is selected according to the purpose of simulation, parameters of the selected model are appropriately set, and the accuracy of the model is verified by means of past data.(3) Run SimulationAn environment for running a simulation is constructed, and the simulation is run by means of the constructed model. Results of the simulation are visualized by graphs, drawings, and the like.It is possible to correct rotation of the head 1 with high accuracy by applying a simulation using big data such as shape data and correction data in each embodiment.

[0157] Digital TwinA digital twin that connects the real world and a virtual space is technology that enables prediction, optimization, or the like of the real world by reproducing, in the virtual space, an object in the real world and simulating the behavior thereof. Simulation is the heart of the digital twin and is an important tool for performing various experiments and analyses in the virtual space based on real-world data. Simulation data brings advantages such as improvement in prediction accuracy, optimization, risk reduction, cost reduction, and the like by quantifying and modeling a complicated phenomenon in the real world. The digital twin is expected to be more sophisticated in cooperation with Al or Internet of Things (loT). For example, it is conceivable that simulation accuracy may be improved by use of machine learning, or real-time simulation may be implemented by utilization of edge computing.

[0158] An example of a method for applying the simulation data in each embodiment to the digital twin will be described below.

[0159] (1) Preprocessing of Simulation DataData cleaning for processing noise, a missing value, or the like included in the collected simulation data is executed to improve the quality of data. Data conversion is performed to convert the simulation data subjected to data cleaning into a format that can be handled by the simulation model.

[0160] (2) Construction of Simulation ModelA model is constructed which describes physical characteristics of an object to be simulated. A mathematical model is constructed which expresses the constructed physical model by a mathematical equation. An algorithm for numerically solving the constructed mathematical model is developed.

[0161] (3) Integration into Digital TwinFN202501242Simulation results are displayed in a visually easy-to-understand format such as a 3D model or a graph. Thus, the simulation results are visualized. The visualized simulation results are compared with data such as measurement data and sensor data in the real world, and the accuracy of the model is verified. Adjusting real-world control parameters based on the simulation results enhances the accuracy of the verified model.

[0162] Applying the simulation data in each embodiment to the digital twin makes it possible to simulate a correction to be made to the rotation of the head 1 to be used when coating of the coating target surface is performed. This principle can also be applied to simulate heads to be mounted on various printers.

[0163] Although some embodiments and variations have been described above, embodiments of the present disclosure are not limited to the above-described embodiments and variations.Various modifications and substitutions may be made to the above-described embodiments without departing from the scope described in the appended claims.

[0164] The numbers such as ordinal numbers and quantity used in the description of the above embodiments are all illustrative for the purpose of specifically describing the technology of the embodiments of the present disclosure, and the embodiments of the present disclosure are not limited to the illustrative numbers. Furthermore, a connection relation between the components is exemplified for the purpose of describing the technology of the embodiments of the present disclosure, and the connection relation to enable the functions of the present disclosure is not limited to the connection relation as described above.

[0165] Furthermore, division of functional blocks illustrated in the block diagram is an example, and multiple blocks may be implemented as one block, one block may be divided into multiple blocks, or some functions may be transferred to another block. Furthermore, functions of multiple blocks having similar functions may be processed in parallel or in time division by a single piece of hardware or software. Some or all of the functions according to the above embodiments of the present disclosure may be distributed to multiple computers.

[0166] Examples of the liquid include a solution, a suspension, or an emulsion that contains, for example, a solvent, such as water or an organic solvent, a colorant, such as dye or pigment, a functional material, such as a polymerizable compound, a resin, or a surfactant, a biocompatible material, such as DNA, amino acid, protein, or calcium, or an edible material, such as a natural colorant. Such a solution, a suspension, or an emulsion is used as, for example, inkjet ink, coating paint, surface treatment solution, a liquid for forming components of an electronic element or light-emitting element or an electronic-circuit resist pattern, or a material solution for three-dimensional fabrication.

[0167] FN202501242The coating target surface S represents a material to which liquid adheres and sticks, a material to be permeated by liquid that adheres thereto, or the like. Examples thereof include recording media, such as a vehicle body, construction material, a paper sheet, recording paper, a recording sheet of paper, a film, and cloth, an electronic component, such as an electronic substrate and a piezoelectric element, and media, such as a powder layer, an organ model, and a testing cell. The examples include any surface to which liquid can adhere, unless particularly limited.

[0168] Each function of the embodiments described above can be implemented by one or more processing circuits. The term “processing circuit or circuitry” in the present specification includes a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, and devices, such as an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a field-programmable gate array (FPGA), and conventional circuit components arrayed to perform the recited functions.The present invention can be implemented in any convenient form, for example using dedicated hardware, or a mixture of dedicated hardware and software. The present invention maybe implemented as computer software implemented by one or more networked processing apparatuses. The processing apparatuses include any suitably programmed apparatuses such as a general purpose computer, a personal digital assistant, a Wireless Application Protocol (WAP) or third-generation (3G)-compliant mobile telephone, and so on. Since the present invention can be implemented as software, each and every aspect of the present invention thus encompasses computer software implementable on a programmable device. The computer software can be provided to the programmable device using conventional carrier medium (carrier means). The carrier medium includes a transient carrier medium such as an electrical, optical, microwave, acoustic or radio frequency signal carrying the computer code. An example of such transient medium is a Transmission Control Protocol / Internet Protocol (TCP / IP) signal carrying computer code over an IP network, such as the Internet. The carrier medium may also include a storage medium for storing processor readable code such as a floppy disk, a hard disk, a compact disc read-only memory (CD-ROM), a magnetic tape device, or a solid state memory device.A liquid discharge apparatus includes: a head including a nozzle plate having nozzles arrayed in a main scanning direction, the head configured to discharge a liquid from the nozzles to coat a target surface with the liquid to perform a coating operation; a variable mechanism configured to change a position and an orientation of the head relative to the target surface; and a controller configured to: select a nozzle group from the nozzles based on: a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the liquid discharge apparatus performs the coating operation; and a relative movement speed of the head, relative to the target surface, moved by the variable mechanism; control the head to discharge the liquid, from the nozzles of theFN202501242nozzle group selected, onto the target surface to form a correction pattern on the target surface while controlling the variable mechanism to move the head relative to the target surface; acquire rotation information on rotation of the head about a rotation axis along a normal line of the nozzle plate based on the correction pattern formed on the target surface; correct the rotation of the head based on the rotation information; and control the head, the rotation of which is corrected, to discharge the liquid from the nozzles while controlling the variable mechanism to move the head relative to the target surface.The liquid discharge apparatus further includes: a vibration detector configured to detect the vibration, and the controller selects the nozzle group based on: the maximum vibration frequency component in the vibration detected by the vibration detector; and the relative movement speed of the head. The variable mechanism moves the head relative to the target surface in the main scanning direction, the controller selects, from the nozzles, the nozzle group having phases of displacement of the correction pattern aligned in a subscanning direction orthogonal to the main scanning direction, when the correction pattern is displaced in the sub-scanning direction by a relative movement of the head relative to the target surface.The liquid discharge apparatus further includes: a bend detector configured to detect an amount of bend of the liquid discharged from the head, and the controller corrects the rotation of the head based on the amount of bend detected by the bend detector.The controller is further configured to: select the nozzle group from the nozzles arranged at a distance of (n / 2) x (v / f) between the nozzles in the main scanning direction; control the head to discharge the liquid onto the target surface from the nozzles of the nozzle group selected to form the correction pattern on the target surface; and control the variable mechanism to change the orientation of the head, at each predetermined teaching position in the main scanning direction, based on the correction pattern, where n is an integer; f is the maximum vibration frequency component; and v is the relative movement speed of the head.The controller is further configured to: select the nozzle group from the nozzles arranged at a distance of {(2n - l) / 2 } x (v / f) between the nozzles in the main scanning direction; control the head to discharge the liquid onto the target surface from the nozzles of the nozzle group selected to form the correction pattern on the target surface; and control the variable mechanism to change the orientation of the head, at each predetermined teaching position in the main scanning direction, based on the correction pattern, where n is an integer; f is the maximum vibration frequency component; and v is the relative movement speed of the head.The controller is further configured to: control the head to discharge the liquid from each of two nozzles in the nozzle group onto the target surface to form the correction pattern on the target surface; and acquire information on amplitude of displacement of the correction pattern in a sub-scanning direction orthogonal to the main scanning direction.The controller is further configured to: control the head to discharge the liquid from each of two nozzles in the nozzle group onto the target surface to form the correction patternFN202501242on the target surface; and acquire information on a shift of the head in a sub-scanning direction orthogonal to the main scanning direction.A liquid discharge method includes: discharging liquid from nozzles, arrayed in a main scanning direction on a nozzle plate of a head, to coat a target surface with the liquid to perform a coating operation, changing a position and an orientation of the head relative to the target surface by a variable mechanism; selecting a nozzle group from the nozzles based on: a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the coating operation is performed; and a relative movement speed of the head, relative to the target surface, moved by the variable mechanism; controlling the head to discharge the liquid, from the nozzles of the nozzle group selected, onto the target surface to form a correction pattern on the target surface while controlling the variable mechanism to move the head relative to the target surface; acquiring rotation information on rotation of the head about a rotation axis along a normal line of the nozzle plate based on the correction pattern formed on the target surface; correcting the rotation of the head based on the rotation information; and controlling the head, the rotation of which is corrected, to discharge the liquid from the nozzles while controlling the variable mechanism to move the head relative to the target surface.A recording medium storing a plurality of instructions which, when executed by one or more processors, causes the one or more processors to perform a method, includes: discharging liquid from nozzles, arrayed in a main scanning direction on a nozzle plate of a head, to coat a target surface with the liquid to perform a coating operation, changing a position and an orientation of the head relative to the target surface by a variable mechanism; selecting a nozzle group from the nozzles based on: a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the coating operation is performed; and a relative movement speed of the head, relative to the target surface, moved by the variable mechanism; controlling the head to discharge the liquid, from the nozzles of the nozzle group selected, onto the target surface to form a correction pattern on the target surface while controlling the variable mechanism to move the head relative to the target surface; acquiring rotation information on rotation of the head about a rotation axis along a normal line of the nozzle plate based on the correction pattern formed on the target surface; correcting the rotation of the head based on the rotation information; and controlling the head, the rotation of which is corrected, to discharge the liquid from the nozzles while controlling the variable mechanism to move the head relative to the target surface.

[0169] Aspects of the present disclosure are, for example, as follows.Aspect 1FN202501242According to Aspect 1, a liquid discharge apparatus for discharging liquid to coat a coating target surface with the liquid, includes: a head including a nozzle plate, the head being configured to individually discharge a liquid from nozzles formed in the nozzle plate, the nozzles being arrayed in a main scanning direction; a variable mechanism that changes a position and an orientation of the head relative to the coating target surface; and a controller that controls operation of each of the head and the variable mechanism, in which the controller forms a correction pattern on the coating target surface by using a nozzle group selected from the nozzles, the nozzle group being selected based on a maximum vibration frequency component and a predetermined relative movement speed of the head, the maximum vibration frequency component being largest of multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in vibration generated in at least one of the head and the variable mechanism when the liquid discharge apparatus performs coating operation, the relative movement speed of the head being a speed of relative movement of the head caused by the variable mechanism, the controller acquires information on rotation of the head based on the correction pattern formed on the coating target surface, the rotation of the head being rotation about a rotation axis along a normal line of the nozzle plate, and the controller controls discharge of the liquid from the head by correcting the rotation of the head based on the information on the rotation, the head being subjected to relative movement by the variable mechanism.Aspect 2According to Aspect 2, the liquid discharge apparatus of Aspect 1, further includes: a vibration detector that detects vibration generated in at least one of the head and the variable mechanism when the liquid discharge apparatus performs coating operation, in which the controller selects the nozzle group based on a maximum vibration frequency component and the predetermined relative movement speed of the head, the maximum vibration frequency component being largest of multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in the vibration detected by the vibration detector, the relative movement speed of the head being the speed of relative movement of the head caused by the variable mechanism.Aspect 3According to Aspect 3, in the liquid discharge apparatus of Aspect 1 or Aspect 2, the controller selects, from the nozzles, the nozzle group that allows alignment of phases of displacement of the correction pattern in a sub-scanning direction orthogonal to the main scanning direction, the displacement being caused in response to relative movement of the head in the main scanning direction, the relative movement being caused by the variable mechanism.Aspect 4According to Aspect 4, the liquid discharge apparatus of any one of Aspects 1 to 3, further includes: a bend detector that detects an amount of bend of the liquid discharged from theFN202501242head, in which the controller corrects the rotation of the head based on the amount of bend detected by the bend detector, the head being subjected to relative movement by the variable mechanism.Aspect 5According to Aspect 5, in the liquid discharge apparatus of any one of Aspects 1 to 4, when n is an integer, f is the maximum vibration frequency component that is the largest of the multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in the vibration generated in at least one of the head and the variable mechanism when the liquid discharge apparatus performs coating operation, and v is the predetermined relative movement speed of the head, the relative movement speed of the head being the speed of relative movement of the head caused by the variable mechanism, the controller forms the correction pattern on the coating target surface by using the nozzle group selected such that a distance between the nozzles in the main scanning direction is expressed as (n / 2) x (v / f), and the controller creates the correction data based on the correction pattern at each predetermined teaching position in the main scanning direction, orientation of the head being changed by the variable mechanism at each predetermined teaching position.Aspect 6According to Aspect 6, in the liquid discharge apparatus of any one of Aspects 1 to 5, when n is an integer, f is the maximum vibration frequency component that is the largest of the multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in the vibration generated in at least one of the head and the variable mechanism when the liquid discharge apparatus performs coating operation, and v is the predetermined relative movement speed of the head, the relative movement speed of the head being the speed of relative movement of the head caused by the variable mechanism, the controller forms the correction pattern on the coating target surface by using the nozzle group selected such that a distance between the nozzles in the main scanning direction is expressed as {(2n - l) / 2 } x (v / f), and the controller creates the correction data based on the correction pattern at each predetermined teaching position in the main scanning direction, orientation of the head being changed by the variable mechanism at each predetermined teaching position.Aspect 7According to Aspect 7, in the liquid discharge apparatus of Aspect 6, the controller acquires information on amplitude of displacement of the correction pattern in a sub-scanning direction orthogonal to the main scanning direction, based on the correction pattern formed by the liquid discharged from each of two nozzles included in the nozzle group.Aspect 8According to Aspect 8, in the liquid discharge apparatus of Aspect 6, based on the correction pattern formed by the liquid discharged from each of two nozzles included in the nozzle group, the controller acquires information on a shift of the head in a sub-scanning directionFN202501242orthogonal to the main scanning direction, the shift being caused in response to relative movement in the main scanning direction.Aspect 9According to Aspect 9, a liquid discharge method to be performed by a liquid discharge apparatus for discharging liquid to coat a coating target surface with the liquid, includes: causing a head including a nozzle plate to individually discharge a liquid from nozzles formed in the nozzle plate, the nozzles being arrayed in a main scanning direction; causing a variable mechanism to change a position and an orientation of the head relative to the coating target surface; and causing a controller to control operation of each of the head and the variable mechanism, in which the controller forms a correction pattern on the coating target surface by using a nozzle group selected from the nozzles, the nozzle group being selected based on a maximum vibration frequency component and a predetermined relative movement speed of the head, the maximum vibration frequency component being largest of multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in vibration generated in at least one of the head and the variable mechanism when the liquid discharge apparatus performs coating operation, the relative movement speed of the head being a speed of relative movement of the head caused by the variable mechanism, the controller acquires information on rotation of the head based on the correction pattern formed on the coating target surface, the rotation of the head being rotation about a rotation axis along a normal line of the nozzle plate, and the controller controls discharge of the liquid from the head by correcting the rotation of the head based on the information on the rotation, the head being subjected to relative movement by the variable mechanism.Aspect 10According to Aspect 10, a recording medium stores a program to be executed in a liquid discharge apparatus for discharging liquid to coat a coating target surface with the liquid, the program causing the liquid discharge apparatus to perform: a step of causing a head including a nozzle plate to individually discharge a liquid from nozzles formed in the nozzle plate, the nozzles being arrayed in a main scanning direction; a step of causing a variable mechanism to change a position and an orientation of the head relative to the coating target surface; and a step of causing a controller to control operation of each of the head and the variable mechanism, in which the controller forms a correction pattern on the coating target surface by using a nozzle group selected from the nozzles, the nozzle group being selected based on a maximum vibration frequency component and a predetermined relative movement speed of the head, the maximum vibration frequency component being largest of multiple vibration frequency components in terms of vibration amplitude, the multiple vibration frequency components being included in vibration generated in at least one of the head and the variable mechanism when the liquid discharge apparatus performs coating operation, the relative movement speed of the head being a speed of relative movement of the head caused by the variable mechanism, the controller acquires information on rotation of the head based on theFN202501242correction pattern formed on the coating target surface, the rotation of the head being rotation about a rotation axis along a normal line of the nozzle plate, and the controller controls discharge of the liquid from the head by correcting the rotation of the head based on the information on the rotation, the head being subjected to relative movement by the variable mechanism.The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above 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. 2024-229090, filed on December 25, 2024, in the Japan Patent Office, and Japanese Patent Application No. 2025-159876, filed on September 26, 2025, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.[Reference Signs List]

[0170] 1, 1Y, IM, 1C, IK, 1W head2 variable mechanism3 controller4 supply mechanism5 vibration detector6 imaging unit7 bend detector31 central processing unit (CPU)32 read only memory (ROM)33 random access memory (RAM)34 hard disk drive (HDD) / solid state drive (SSD)35 device connection interface (I / F)36 communication I / F100, 100a, 100b liquid discharge apparatus110 housing111 supply port112 collection port113 connector230 compressor301 input unit302 nozzle group selection unit303 rotation information acquisition unit304 correction data creation unitFN202501242305 head controller306 variable mechanism controller307 supply controller308 output unit309 amplitude information acquisition unit 310 shift information acquisition unit 311, 311-1, 311-2, 311-3, 311-4 nozzle 321 nozzle plate322 channel324 piezoelectric element325 liquid330, 33OY, 33OM, 33OC, 33OK liquid tank 331 pipe332 air regulator333 tube340 discharge module350 nozzle surface351 nozzle row360 nozzle groupA main scanning directionB sub- scanning directionCL center lined, dl, d2, d3 intervaldmax maximum intervaldmin minimum intervalE, El, E2 correction patternf maximum vibration frequency component G amplitudeIP ideal pathL, LI, L2, L3, L4 linear patternN normal lineP position signalRC rotation axisSB system busSD shape dataSP meandering pathT1 synchronization signalT2 interval signalT3 discharge signalTd delay timeFN202501242Tout discharge timeTP teaching positionv relative movement speed 91, 92 rotation angle [Citation List][Patent Literature]

[0171] [PTL 1]Japanese Patent No. 7521360

Claims

1. FN202501242[CLAIMS]1. A liquid discharge apparatus comprising:a head including a nozzle plate having nozzles arrayed in a main scanning direction, the head configured to discharge a liquid from the nozzles to coat a target surface with the liquid to perform a coating operation;a variable mechanism configured to change a position and an orientation of the head relative to the target surface; anda controller configured to:select a nozzle group from the nozzles based on:a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the liquid discharge apparatus performs the coating operation; anda relative movement speed of the head, relative to the target surface, moved by the variable mechanism;control the head to discharge the liquid, from the nozzles of the nozzle group selected, onto the target surface to form a correction pattern on the target surface while controlling the variable mechanism to move the head relative to the target surface;acquire rotation information on rotation of the head about a rotation axis along a normal line of the nozzle plate based on the correction pattern formed on the target surface;correct the rotation of the head based on the rotation information; andcontrol the head, the rotation of which is corrected, to discharge the liquid from the nozzles while controlling the variable mechanism to move the head relative to the target surface.

2. The liquid discharge apparatus according to claim 1, further comprising: a vibration detector configured to detect the vibration,wherein the controller selects the nozzle group based on:the maximum vibration frequency component in the vibration detected by the vibration detector; andthe relative movement speed of the head.

3. The liquid discharge apparatus according to claim 1 or 2,wherein the variable mechanism moves the head relative to the target surface in the main scanning direction,the controller selects, from the nozzles, the nozzle group having phases of displacement of the correction pattern aligned in a sub-scanning direction orthogonal to the main scanning direction,when the correction pattern is displaced in the sub-scanning direction by a relative movement of the head relative to the target surface.FN2025012424. The liquid discharge apparatus according to claim 1, further comprising: a bend detector configured to detect an amount of bend of the liquid discharged from the head,wherein the controller corrects the rotation of the head based on the amount of bend detected by the bend detector.

5. The liquid discharge apparatus according to claim 1,wherein the controller is further configured to:select the nozzle group from the nozzles arranged at a distance of (n / 2) x (v / f) between the nozzles in the main scanning direction;control the head to discharge the liquid onto the target surface from the nozzles of the nozzle group selected to form the correction pattern on the target surface; andcontrol the variable mechanism to change the orientation of the head, at each predetermined teaching position in the main scanning direction, based on the correction pattern,where n is an integer;f is the maximum vibration frequency component; andv is the relative movement speed of the head.

6. The liquid discharge apparatus according to claim 1,wherein the controller is further configured to:select the nozzle group from the nozzles arranged at a distance of {(2n - l) / 2 } x (v / f) between the nozzles in the main scanning direction;control the head to discharge the liquid onto the target surface from the nozzles of the nozzle group selected to form the correction pattern on the target surface; andcontrol the variable mechanism to change the orientation of the head, at each predetermined teaching position in the main scanning direction, based on the correction pattern,where n is an integer;f is the maximum vibration frequency component; andv is the relative movement speed of the head.

7. The liquid discharge apparatus according to claim 6,wherein the controller is further configured to:control the head to discharge the liquid from each of two nozzles in the nozzle group onto the target surface to form the correction pattern on the target surface; andacquire information on amplitude of displacement of the correction pattern in a subscanning direction orthogonal to the main scanning direction.

8. The liquid discharge apparatus according to claim 6,FN202501242wherein the controller is further configured to:control the head to discharge the liquid from each of two nozzles in the nozzle group onto the target surface to form the correction pattern on the target surface; andacquire information on a shift of the head in a sub- scanning direction orthogonal to the main scanning direction.

9. A liquid discharge method comprising:discharging liquid from nozzles, arrayed in a main scanning direction on a nozzle plate of a head, to coat a target surface with the liquid to perform a coating operation, changing a position and an orientation of the head relative to the target surface by a variable mechanism;selecting a nozzle group from the nozzles based on:a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the coating operation is performed; anda relative movement speed of the head, relative to the target surface, moved by the variable mechanism;controlling the head to discharge the liquid, from the nozzles of the nozzle group selected, onto the target surface to form a correction pattern on the target surface while controlling the variable mechanism to move the head relative to the target surface;acquiring rotation information on rotation of the head about a rotation axis along a normal line of the nozzle plate based on the correction pattern formed on the target surface;correcting the rotation of the head based on the rotation information; and controlling the head, the rotation of which is corrected, to discharge the liquid from the nozzles while controlling the variable mechanism to move the head relative to the target surface.

10. A recording medium storing a plurality of instructions which, when executed by one or more processors, causes the one or more processors to perform a method, comprising:discharging liquid from nozzles, arrayed in a main scanning direction on a nozzle plate of a head, to coat a target surface with the liquid to perform a coating operation, changing a position and an orientation of the head relative to the target surface by a variable mechanism;selecting a nozzle group from the nozzles based on:a maximum vibration frequency component that is a largest of multiple vibration frequency components in terms of vibration amplitude in vibration generated in at least one of the head and the variable mechanism when the coating operation is performed; andFN202501242a relative movement speed of the head, relative to the target surface, moved by the variable mechanism;controlling the head to discharge the liquid, from the nozzles of the nozzle group selected, onto the target surface to form a correction pattern on the target surface while controlling the variable mechanism to move the head relative to the target surface;acquiring rotation information on rotation of the head about a rotation axis along a normal line of the nozzle plate based on the correction pattern formed on the target surface;correcting the rotation of the head based on the rotation information; and controlling the head, the rotation of which is corrected, to discharge the liquid from the nozzles while controlling the variable mechanism to move the head relative to the target surface.

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