Liquid ejection device, liquid ejection method, and program

Abstract

To provide a liquid discharge device that is excellent in productivity.SOLUTION: A liquid discharge device according to one embodiment of the present invention, which discharges liquid and applies the liquid to an object, comprises a head for discharging the liquid, a variable mechanism that can vary relative positions of the object and the head in response to a command, and a control part that controls the head so that the head discharges the liquid, in a plurality discharging positions which are positions of the head at the time when the head discharges the liquid, while passing on a plurality of command positions which are positions corresponding to the command. The control part controls the relative positions by the variable mechanism so that a discharge distance which is a distance between the surface of the object and the head in a normal direction of the surface of the object become uneven at least in some of the plurality of discharging positions.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection apparatus, a liquid ejection method, and a program. [Background technology]

[0002] 2. Description of the Related Art Conventionally, liquid ejection devices that eject liquid onto an object are known, and such liquid ejection devices are used in applications such as coating the surface of the object with liquid.

[0003] As the liquid ejection device, a configuration has been disclosed in which a head having a nozzle for ejecting liquid is moved along the three-dimensional shape of an object in order to uniformly apply a liquid such as a coating agent to the surface of the object having a three-dimensional shape (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the liquid ejection device of Patent Document 1, the head is moved so as to maintain a constant distance between the target surface and the head in the normal direction of the target surface, which reduces the head movement speed and reduces the productivity of the liquid ejection device, leaving room for improvement.

[0005] An object of the present invention is to provide a liquid ejection apparatus that is excellent in productivity. [Means for solving the problem]

[0006] A liquid ejection device according to one aspect of the present invention is a liquid ejection device that ejects liquid onto a target object, and includes a head that ejects the liquid, a variable mechanism that can change the relative position between the target object and the head in response to a command, and a control unit that controls the head to eject the liquid at a plurality of ejection positions that are positions of the head when ejecting the liquid from the head while passing through a plurality of command positions that are positions corresponding to the command, and the control unit controls the change of the relative position by the variable mechanism so that a ejection distance, which is the distance between the target object surface and the head in a normal direction to the target object surface, is non-uniform at least in part of the plurality of ejection positions. The control unit thins out some of the plurality of command positions obtained at predetermined intervals based on the discharge distance. . [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a liquid ejection apparatus with excellent productivity. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of the overall configuration of a liquid ejection device according to a first embodiment. [Figure 2] 1 is a block diagram illustrating an example of the overall configuration of a liquid ejection device according to a first embodiment. [Figure 3] FIG. 4 is a diagram showing a first example of the relationship between a command position and a discharge position according to the first embodiment. [Figure 4] FIG. 10 is a diagram showing a second example of the relationship between a command position and a discharge position according to the first embodiment. [Figure 5] FIG. 10 is a diagram illustrating a discharge distance by a head. [Figure 6] FIG. 10 is a diagram illustrating the relative angle of the head. [Figure 7] FIG. 2 is a block diagram illustrating an example of the hardware configuration of a control unit according to the first embodiment. [Figure 8] FIG. 2 is a block diagram illustrating an example of the functional configuration of a control unit according to the first embodiment. [Figure 9] FIG. 10 is a diagram illustrating an example of command position information. [Figure 10]4 is a flowchart of an example of a command generation process by a control unit according to the first embodiment. FIG. [Figure 11] FIG. 10 is a flowchart of an example of verification processing by a control unit according to the first embodiment. [Figure 12] 5 is a timing chart showing an example of the operation of the liquid ejection device according to the first embodiment. FIG. [Figure 13] FIG. 10 is a perspective view illustrating the configuration of a head according to a second embodiment. [Figure 14] FIG. 14 is a cross-sectional view of the head taken along plane S1 in FIG. [Figure 15] FIG. 10 is a timing chart illustrating an example of the operation of the liquid ejection device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A liquid ejection device according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the following embodiments are merely examples of liquid ejection devices that embody the technical concept of the present embodiment, and are not intended to be limiting. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in the embodiments are merely illustrative examples and are not intended to limit the scope of the present invention. Note that the size, positional relationship, etc. of components shown in each drawing may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate the same or similar components, and detailed description will be omitted as appropriate.

[0010] [First embodiment] <Example of overall configuration of liquid ejection device 10> The overall configuration of a liquid ejection device 10 according to the first embodiment will be described with reference to Figures 1 and 2. Figures 1 and 2 are diagrams illustrating the overall configuration of the liquid ejection device 10, with Figure 1 being a schematic diagram and Figure 2 being a block diagram.

[0011] 1 and 2, the liquid ejection device 10 has a head 1, a variable mechanism 2, and a control unit 3. The liquid ejection device 10 is a coating device that coats the surface of the object 200 by ejecting a liquid Q from the head 1 using an inkjet system and applying the liquid Q to the object 200. The liquid Q is paint, ink, or the like.

[0012] The object 200 is an object having an impermeable surface, such as the body of a car, truck, or airplane. Impermeability refers to the property that a liquid applied to a surface does not penetrate into the interior. However, the surface of the object 200 is not limited to an impermeable surface, and may be a permeable surface. Furthermore, the surface of the object 200 is a curved surface having a curvature, but may also be a flat surface.

[0013] The head 1 ejects the liquid Q. The head 1 is, for example, a valve jet type head that ejects the liquid Q from its own nozzle onto the target object 200 by opening and closing the nozzle. However, the head 1 is not limited to the valve jet type, and may be driven by other driving methods such as piezoelectric driving or electrostatic driving. The head 1 is particularly a valve jet type head, and is a single nozzle head having one nozzle.

[0014] The variable mechanism 2 can change the relative position and relative angle between the object 200 and the head 1 in response to a command. The variable mechanism 2 is, for example, a robot arm capable of multi-axis drive. The variable mechanism 2 can move the head 1 held at the end of the robot arm in response to a command and change the angle (posture) of the head 1. However, the variable mechanism 2 is not limited to a robot arm, and may be configured with a stage that can move linearly in three axial directions, for example. Furthermore, the variable mechanism 2 may move the object 200 without moving the head 1, or may move both the head 1 and the object 200.

[0015] The control unit 3 controls the head 1 to eject the liquid Q at a plurality of ejection positions, which are positions of the head 1 when ejecting the liquid Q from the head 1, while passing through a plurality of command positions, which are positions corresponding to commands to the variable mechanism 2. Particularly in this embodiment, the control unit 3 controls the change of the relative position by the variable mechanism 2 so that the ejection distance d, which is the distance between the surface of the target object 200 and the head 1 in the normal direction 200a of the surface of the target object 200, is non-uniform at least at some of the plurality of ejection positions.

[0016] The control unit 3 is constructed by, for example, a PC (Personal Computer) or the like. The control unit 3 is connected to the variable mechanism 2 and the head 1 via wire or wirelessly so that they can communicate with each other. Based on the shape information Od, the control unit 3 outputs a drive command Rc to the variable mechanism 2 to drive the variable mechanism 2, and outputs a drive signal Hc to the head 1 to eject the liquid Q from the head 1.

[0017] The shape information Od is shape information of the object 200 transmitted from an external device such as an external PC. The shape information Od is shape information generated when the object 200 is designed, or shape information obtained by measuring the object 200 with a three-dimensional measuring device.

[0018] <Relationship between the command position to the variable mechanism 2 and the ejection position by the head 1> 3 and 4 are diagrams showing the relationship between the command position Td and the discharge position P in the liquid discharge device 10, with Fig. 3 being a diagram of a first example and Fig. 4 being a diagram of a second example. Figs. 3 and 4 show the target object 200, a plurality of command positions Td, a plurality of discharge positions P, a discharge distance d, and a discharge interval e.

[0019] The multiple command positions Td are information that serves as the basis for changing the relative position between the head 1 and the target object 200, and in this embodiment are commands that represent the position of the head 1. In this embodiment, the command positions Td further include information on the relative angle of the head 1, and the variable mechanism 2 can change both the relative position and relative angle of the head 1.

[0020] The ejection position P represents the position of the head 1 when the liquid Q is ejected from the head 1. The ejection interval e is the interval between adjacent ejection positions among the multiple ejection positions P. The ejection interval e corresponds to, for example, the minimum interval at which the liquid Q is applied by the head 1.

[0021] In the first example shown in Figure 3, the number of ejection positions P is equal to the number of command positions Td. The control unit 3 outputs a command position Td for each of the multiple ejection positions P to the variable mechanism 2. The head 1 ejects the liquid Q from the nozzle at each of the multiple ejection positions P. Note that Figure 3 shows an example in which the ejection positions P and the command positions Td overlap, but the ejection positions P and the command positions Td do not necessarily have to coincide.

[0022] Since the discharge distance d is specified for each of the plurality of command positions Td, the discharge distance d at each of the plurality of discharge positions P is substantially the same discharge distance d0. In other words, the discharge distance d at each of the plurality of discharge positions P is uniform.

[0023] As in the first example, when the number of ejection positions P and the number of command positions Td match, the ejection distance d becomes uniform, and the liquid Q can be ejected along the normal direction to the surface of the target object 200. This makes it possible to make the amount of liquid Q applied to the surface of the target object 200 approximately uniform. However, on the other hand, the relative position and relative angle of the head 1 are changed for each of the multiple ejection positions P so that the ejection distance d is constant, which reduces the movement speed of the head 1. This reduces the productivity of the liquid ejection device 10.

[0024] On the other hand, in the second example shown in Fig. 4, many of the multiple command positions Td have been thinned out compared to Fig. 3, leaving only three command positions Td1, Td2, and Td3.

[0025] In FIG. 4, the white circles between the commanded positions Td1 and Td2 represent ejection positions P. The ejection positions P include the positions of the white circles between the commanded positions Td1 and Td2, the positions of the white circles between the commanded positions Td2 and Td3, and the positions of the commanded positions Td1, Td2, and Td3. The control unit 3 can obtain information on the multiple ejection positions P by calculation based on the multiple command positions Td and the shape information Od. The head 1 ejects liquid Q at each of the multiple ejection positions P while being moved from the commanded position Td1 to the commanded position Td2 by the variable mechanism 2.

[0026] At each of the command positions Td1, Td2, and Td3, the variable mechanism 2 changes the relative position of the head 1 so that the discharge distance d becomes discharge distance d0. The variable mechanism 2 also changes the relative angle of the head 1 so that the discharge direction of the liquid Q from the head 1 becomes approximately parallel to the normal direction of the surface of the target object 200.

[0027] On the other hand, the variable mechanism 2 does not change the relative position or relative angle between the commanded position Td1 and the commanded position Td2. The head 1 moves linearly between the commanded position Td1 and the commanded position Td2, and ejects the liquid Q at a plurality of ejection positions P on the straight line that passes through the commanded position Td1 and the commanded position Td2.

[0028] Since the head 1 moves linearly between command positions Td1 and Td2, if the target object 200 has a curved surface, the discharge distance d will differ for each discharge position P depending on the deviation between the curved surface and the straight line. For example, the discharge distance d1 at discharge position P1, the discharge distance d2 at discharge position P2, and the discharge distance d0 are all different from one another. That is, in the second example shown in FIG. 4, the discharge distances d are non-uniform at multiple discharge positions P.

[0029] In this embodiment, as in the second example, a decrease in productivity of the liquid ejection device 10 is suppressed by thinning out some of the multiple command positions Td and not changing the discharge distance d and relative angle for each of the multiple discharge positions P. On the other hand, thinning out some of the multiple command positions Td may result in uneven discharge distances d, which in turn may result in uneven amounts of liquid Q applied to the surface of the target object 200, resulting in a decrease in the quality of liquid application by the liquid ejection device 10. In response to this, in this embodiment, threshold conditions for ensuring liquid application quality are set for each of the discharge distance d and the relative angle. Then, by thinning out some of the multiple command positions Td under conditions where the discharge distance d and relative angle can ensure coating quality, it is possible to suppress a decrease in productivity while ensuring liquid application quality.

[0030] 5 is a diagram illustrating the discharge distance by the head 1. The maximum distance dx is the maximum discharge distance d that is permissible for ensuring liquid deposition quality. The minimum distance dn is the minimum discharge distance d that is permissible for ensuring liquid deposition quality. Liquid deposition quality can be ensured by thinning out some of the multiple command positions Td so that the discharge distance d for each of the multiple discharge positions P is equal to or greater than the minimum distance dn and equal to or less than the maximum distance dx.

[0031] FIG. 6 is a diagram illustrating the relative angle between the head 1 and the target object 200. The maximum angle Ax is the maximum value of the relative angle A that is allowable to ensure liquid deposition quality. The minimum angle An is the minimum value of the relative angle A that is allowable to ensure liquid deposition quality. Liquid deposition quality can be ensured by thinning out some of the multiple command positions Td so that the relative angle A for each of the multiple ejection positions P is equal to or greater than the minimum angle An and equal to or less than the maximum angle Ax.

[0032] <Configuration example of control unit 3> (Example of hardware configuration) 7 is a block diagram illustrating an example of the hardware configuration of the control unit 3. The control unit 3 has a CPU (Central Processing Unit) 31, a ROM (Read Only Memory) 32, a RAM (Random Access Memory) 33, an HDD (Hard Disk Drive) / SSD (Solid State Drive) 34, a connection I / F (Interface) 35, and a communication I / F 36. These are electrically connected to each other via a system bus B.

[0033] The CPU 31 uses the RAM 33 as a work area and executes programs stored in the ROM 32 to control the overall operation of the control unit 3 .

[0034] The ROM 32 is a non-volatile memory that stores programs and other fixed data for controlling the recording operation and the like of the CPU 31. The RAM 33 is a volatile memory that temporarily stores various types of data.

[0035] The HDD / SSD 34 is a non-volatile memory that can store information such as painting area information Pd and shape information Od of the body of the object 200. The information stored in the HDD / SSD 34 is read by the CPU 31 and may be used when the program is executed.

[0036] The connection I / F 35 is an interface for connecting to an external device, such as the variable mechanism 2 or the head 1. The communication I / F 36 is an interface for connecting to an external device, such as an external PC, so as to be able to communicate with the external device.

[0037] (Example of functional configuration of control unit 3) 8 is a block diagram illustrating the functional configuration of the control unit 3 according to the first embodiment. The control unit 3 includes a communication unit 301, an input / output unit 302, a command information generation unit 303, a thinning unit 304, a verification unit 305, a command unit 306, and a discharge control unit 307.

[0038] The control unit 3 can realize the functions of the communication unit 301 by the communication I / F 36 etc., and the functions of the input / output unit 302 by the connection I / F 35 etc. The control unit 3 can also realize the functions of the command information generation unit 303, the thinning unit 304, the verification unit 305, the command unit 306, and the discharge control unit 307 by the CPU 31 executing a program stored in the ROM 32 etc.

[0039] The control unit 3 may have functional components other than those described above. Components other than the control unit 3 may also have some of the above functions. Components other than the control unit 3 include the variable mechanism 2, the head 1, and an external PC. Some of the above functions may be realized by distributed processing of the control unit 3 and components other than the control unit 3. The control unit 3 may also realize at least some of the functions realized by the CPU 31 using electrical circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0040] The communication unit 301 controls the communication of signals and data between the control unit 3 and an external device such as an external PC. The input / output unit 302 controls the input / output of signals and data between the control unit 3 and the variable mechanism 2 and head 1.

[0041] The command information generating unit 303 performs processing to generate information on a plurality of command positions Td. The command information generating unit 303 can generate a plurality of command positions Td based on shape information Od input via the communication unit 301, for example.

[0042] The thinning unit 304 performs processing to thin out some of the multiple command positions Td obtained at predetermined intervals. The thinning unit 304 outputs information on the multiple command positions Te resulting from the thinning to the verification unit 305.

[0043] The verification unit 305 performs processing to verify whether or not a desired liquid deposition quality can be obtained when the liquid Q is discharged onto the target object 200 at a plurality of discharge positions P acquired based on a plurality of command positions Td. If the verification unit 305 verifies that the desired liquid deposition quality can be obtained, it outputs information corresponding to the plurality of command positions Td to the command unit 306 and information corresponding to the plurality of discharge positions P to the discharge control unit 307.

[0044] The control unit 3 performs verification using the verification unit 305 based on the discharge distance d or the relative angle A. The control unit 3 can thin out some of the multiple command positions Td obtained at predetermined intervals using the thinning unit 304 in accordance with the verification result by the verification unit 305.

[0045] The command unit 306 outputs a drive command Rc to the variable mechanism 2 based on the plurality of command positions Td input from the verification unit 305, and changes the relative position and relative angle between the target object 200 and the head 1.

[0046] The ejection control unit 307 controls the ejection of the liquid Q from the head 1 at a plurality of ejection positions P.

[0047] <Example of command position Td> FIG. 9 is a diagram showing an example of a command position Td generated by the command information generating unit 303. In FIG. 9, "MOVJ" means a link interpolation command. Link interpolation is an interpolation command that corresponds to a fast-forward command in an NC machine tool. The servo motors of each joint of the robot arm operate to make them move easily, so the path from the current coordinates to the commanded point according to the link interpolation command will be determined by the robot's processing. "X=100 Y=50 Z=0" means the XYZ coordinate values ​​corresponding to the three-dimensional relative position of the head 1. "A=0 B=45 C=0" means the three-dimensional relative angle of the head 1.

[0048] "MOVL" means a linear interpolation command. "X=200 Y=80 Z=11" means the XYZ coordinate values ​​corresponding to the relative position of the head 1 in three dimensions, and "A=0 B=30 C=0" means the relative angle of the head 1 in three dimensions. Linear interpolation is an interpolation command that corresponds to a linear interpolation command in an NC machine tool. The linear interpolation command moves in a linear trajectory from the current coordinates to the specified point. In this embodiment, since it is necessary to drive the robot arm of the variable mechanism 2 precisely, it is preferable to use "MOVL".

[0049] <Example of processing by control unit 3> (Generation process of command position Td) Fig. 10 is a flowchart showing an example of a process for generating a command position Td by the control unit 3. The control unit 3 starts the process in Fig. 10 in response to an operation input by a user instructing the start of the process for generating the command position Td. The user can perform the operation input using an operation unit or the like of the liquid ejection device 10.

[0050] First, in step S101, the control unit 3 inputs the shape information Od of the object 200 from an external PC or the like via the communication unit 301.

[0051] Subsequently, in step S102, the control unit 3 causes the command information generating unit 303 to generate information on a plurality of command positions Td.

[0052] Next, in step S103, the control unit 3 verifies, using the verification unit 305, whether the desired liquid application quality can be obtained when liquid Q is ejected onto the target object 200 according to each of the multiple command positions Td generated by the command information generation unit 303.

[0053] Next, in step S104, the control unit 3 determines whether the verification result is OK or not using the verification unit 305.

[0054] If it is determined in step S104 that the verification result is OK (Yes in step S104), the control unit 3 performs the process of step S105. On the other hand, if it is determined that the verification result is not OK (No in step S104), the control unit 3 performs the process of step S102 again.

[0055] Subsequently, in step S105, the control unit 3 causes the thinning unit 304 to thin out some of the multiple command positions Td obtained at predetermined intervals.

[0056] Next, in step S106, the control unit 3 verifies, using the verification unit 305, whether the desired liquid application quality can be obtained when liquid Q is ejected onto the target object 200 according to each of the remaining command positions Td thinned out by the thinning unit 304.

[0057] Subsequently, in step S107, the control unit 3 determines whether the verification result is OK by the verification unit 305.

[0058] If it is determined in step S107 that the verification result is OK (step S107, Yes), the control unit 3 performs the process of step S109. On the other hand, if it is determined that the verification result is not OK (step S107, No), the control unit 3 cancels the thinning out of some of the command positions Td that were thinned out in step S105 in step S108. Thereafter, the control unit 3 performs the process of step S105 again. In this case, command positions Td that are different from the command positions Td that were thinned out previously in step S105 are thinned out.

[0059] Subsequently, in step S109, the control unit 3 determines whether or not to end the process. This determination can be made in response to an operation input by the user using the operation unit of the liquid ejection device 10, etc.

[0060] If it is determined in step S109 that the process should be terminated (step S109, Yes), the control unit 3 terminates the process; if it is determined that the process should not be terminated (step S109, No), the control unit 3 performs the process from step S105 onwards again.

[0061] In this way, the control unit 3 can generate information on the command position Td.

[0062] (Verification process) 11 is a flowchart showing an example of the verification process by the control unit 3. The control unit 3 starts the process of FIG. 11 at the timing of step S103 or step S106 in FIG.

[0063] First, in step S111, the control unit 3 causes the verification unit 305 to obtain information on the discharge distance d and the relative angle A for each of the plurality of discharge positions P through calculation.

[0064] Subsequently, in step S112, the control unit 3 determines, by the verification unit 305, whether or not the discharge distance d for each of the plurality of discharge positions P is equal to or greater than the minimum distance dn and equal to or less than the maximum distance dx.

[0065] In step S112, if it is determined that the distance is equal to or greater than the minimum distance dn and equal to or less than the maximum distance dx (step S112, Yes), the control unit 3 proceeds to step S113. If it is determined that the distance is not equal to or greater than the minimum distance dn and equal to or less than the maximum distance dx (step S112, No), the control unit 3 proceeds to step S115 and determines that the verification is NG.

[0066] Subsequently, in step S113, the control unit 3 determines, by the verification unit 305, whether or not the relative angle A for each of the plurality of ejection positions P is equal to or greater than the minimum angle An and equal to or less than the maximum angle Ax.

[0067] In step S113, if it is determined that the angle is equal to or greater than the minimum angle An and equal to or less than the maximum angle Ax (step S113, Yes), the control unit 3 proceeds to step S114 and determines that the verification is OK. On the other hand, if it is determined that the angle is equal to or greater than the minimum angle An and not equal to or less than the maximum angle Ax (step S113, No), the control unit 3 proceeds to step S115 and determines that the verification is NG.

[0068] In this way, the control unit 3 can perform processing to verify whether the desired liquid application quality is obtained when liquid Q is ejected onto the target object 200 at multiple ejection positions P obtained based on multiple command positions Td.

[0069] <Example of operation of the liquid ejection device 10> FIG. 12 is a timing chart showing an example of the operation of the liquid ejection device.

[0070] 12, the position signal Ec indicates the output signal from the rotary encoder provided in the variable mechanism 2. The control unit 3 can obtain the relative position and relative angle of the head 1 held by the variable mechanism 2 by calculation based on the position signal Ec.

[0071] The synchronization signal Sn is a signal for synchronizing the change in relative position and relative angle by the variable mechanism 2 with the ejection of the liquid Q by the head 1. The synchronization signal Sn is output from the variable mechanism 2 and input to the control unit 3.

[0072] The interval signal Ck is a reference signal for defining the minimum interval at which liquid is dispensed by the liquid ejection device 10. For example, if the minimum interval at which liquid is dispensed is 100 [dpi] (=0.254 [mm]), then one pulse of the interval signal Ck is output from the control unit 3 to the head 1 every time the head 1 moves 0.254 [mm].

[0073] The drive signal Hc is a signal for ejecting the liquid Q from the head 1. The delay td indicates the delay time relative to the interval signal Ck, and the ejection time to indicates the time it takes for the nozzles in the head 1 to be opened and the liquid Q to be ejected. The delay td is variable depending on the ejection distance d, ejection speed, etc. The ejection time to is variable depending on the amount of liquid to be ejected, etc.

[0074] <Effects of the liquid ejection device 10> As described above, the liquid ejection device 10 includes the head 1 that ejects the liquid Q, the variable mechanism 2 that can change the relative position between the target object 200 and the head 1 in response to a command, and a control unit that controls the head 1 so that it ejects the liquid Q at multiple ejection positions P while passing through multiple command positions Td. The control unit 3 controls the change in relative position by the variable mechanism 2 so that the ejection distance d is non-uniform at the multiple ejection positions P. Because the liquid ejection device 10 does not change the relative position of the head 1 so that the ejection distance d is uniform at each of the multiple ejection positions P, it is possible to prevent a decrease in the movement speed of the head 1. This makes it possible to provide a liquid ejection device 10 with excellent productivity.

[0075] Furthermore, in this embodiment, the control unit 3 thins out some of the multiple command positions Td obtained at predetermined intervals in accordance with the ejection distance d. By thinning out the command positions T, the number of times the ejection distance d is changed can be reduced. This makes it possible to prevent a decrease in the movement speed of the head 1, and provides a liquid ejection device 10 with excellent productivity.

[0076] Furthermore, in this embodiment, the control unit 3 thins out some of the commanded positions Td when the discharge distance d is equal to or greater than a predetermined minimum distance dn and equal to or less than a maximum distance dx. By thinning out some of the commanded positions Td within a range that ensures the quality of liquid deposition by the liquid ejector 10, it is possible to ensure the quality of liquid deposition while increasing the productivity of the liquid ejector 10.

[0077] Furthermore, in this embodiment, the variable mechanism 2 can further change the relative angle A between the target object 200 and the head 1. The control unit 3 changes at least one of the relative position and the relative angle A so that the discharge distance d is non-uniform at least in part of the multiple command positions Td. Because the relative position and the relative angle A of the head 1 are not controlled so that the discharge distance d is uniform at the multiple discharge positions P, a decrease in the movement speed of the head 1 can be suppressed. This makes it possible to provide a liquid discharge device 10 with excellent productivity.

[0078] Furthermore, in this embodiment, the control unit 3 thins out some of the multiple command positions Td obtained at predetermined intervals in accordance with the relative angle A. By thinning out the command positions T, it is possible to reduce the number of times the relative angle A is changed. This makes it possible to prevent a decrease in the movement speed of the head 1, and to provide a liquid ejection device 10 with excellent productivity.

[0079] Furthermore, in this embodiment, the control unit 3 thins out some of the command positions Td when the relative angle A for each of the command positions Td is equal to or greater than a predetermined minimum angle An and equal to or less than a predetermined maximum angle Ax. By thinning out some of the command positions Td within a range that ensures the quality of liquid deposition by the liquid ejection device 10, it is possible to ensure the quality of liquid deposition while increasing the productivity of the liquid ejection device 10.

[0080] [Second embodiment] A liquid ejection device 10a according to the second embodiment will be described. The same components as those in the first embodiment will be given the same reference numerals, and duplicated descriptions will be omitted where appropriate.

[0081] In this embodiment, the head 1a has a plurality of nozzles. The control unit 3 thins out some of the plurality of command positions Td based on the discharge distance d or the relative angle A of each of the plurality of nozzles.

[0082] <Configuration example of head 1a> 13 and 14 are diagrams illustrating the configuration of a head 1a of a liquid ejection device 10a, Fig. 13 being a perspective view, and Fig. 14 being a cross-sectional view of the head 1a taken along plane S1 in Fig. 13.

[0083] As shown in FIGS. 13 and 14, the head 1 a has a housing 100 , a supply port 101 , a recovery port 102 , a connector 103 , and a plurality of ejection modules 110 .

[0084] The head 1a supplies the liquid Q pressurized from the outside to the ejection module 110 via the supply port 101. The head 1a discharges the liquid Q that has not been ejected via the recovery port 102 to the outside.

[0085] The connector 103 is provided on the housing 100 and allows the drive signal Hc from the control unit 3 to be input thereto.

[0086] The plurality of ejection modules 110 are arranged in one or more rows inside the housing 100. The ejection module 110 includes a nozzle plate 111, a flow path 122, and a piezoelectric member .

[0087] The nozzle plate 111 is provided with nozzles 121 that discharge liquid Q. The nozzle plate 111 is joined to the housing 100. The nozzles 121 communicate with flow paths 122 that supply pressurized liquid Q. The flow paths 122 are common to the multiple discharge modules 110 provided in the housing 100. The piezoelectric member 124 drives a needle-shaped valve element that opens and closes the nozzles 121.

[0088] The head 1a is a valve jet type head that discharges the liquid Q from each of the nozzles 121 onto the target 200 by individually opening and closing the nozzles 121. During the period when the liquid Q is being discharged onto the target 200, the discharge of the liquid Q from the recovery port 102 does not need to be temporarily performed so as not to reduce the discharge efficiency of the liquid Q from the nozzles 121.

[0089] However, the liquid ejection device 10a is not limited to the valve jet type head 1a, and other types of heads such as piezoelectric drive and electrostatic drive may also be used.

[0090] 15 is a timing chart showing an example of the operation of the liquid ejection device 10. The position signal Ec, the synchronization signal Sn, and the interval signal Ck are the same as those in FIG.

[0091] The drive signal Hc_n1 is a signal for ejecting the liquid Q from a first nozzle of the multiple nozzles 121 that the head 1a has. The drive signal Hc_n2 is a signal for ejecting the liquid Q from a second nozzle of the multiple nozzles 121 that the head 1a has. The drive signal Hc_n3 is a signal for ejecting the liquid Q from a third nozzle of the multiple nozzles 121 that the head 1a has. The delay td and ejection time to are the same as those in FIG. 12. Note that although three drive signals Hc are exemplified here, the number of drive signals Hc can be changed as appropriate to match the number of nozzles that the head 1a has.

[0092] As described above, in this embodiment, the head 1a has a plurality of nozzles 121. The control unit 3 thins out some of the plurality of command positions Td based on the discharge distance d or relative angle A of each of the plurality of nozzles 121. As a result, even when using a head 1a having a plurality of nozzles 121, the relative position of the head 1 is not controlled so that the discharge distance d is uniform at the plurality of discharge positions P, and therefore a decrease in the movement speed of the head 1 can be suppressed. This makes it possible to provide a liquid discharge device 10 with excellent productivity.

[0093] Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the present invention.

[0094] In the embodiment, the liquid ejected from the head 1 may be a solution, suspension, emulsion, or the like containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a polymerizable compound, a resin, a surfactant, or the like, a functionalizing material, a biocompatible material such as DNA, amino acids, proteins, or calcium, an edible material such as a natural colorant, etc. These can be used, for example, as inkjet ink, paint, surface treatment liquid, a liquid for forming components of electronic elements or light-emitting elements or electronic circuit resist patterns, a material liquid for 3D modeling, etc.

[0095] The object 200 refers to something to which a liquid adheres and sticks, or something to which a liquid adheres and penetrates, etc. Specific examples include recording media such as car bodies, building materials, paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all things to which a liquid adheres.

[0096] The embodiments also include a liquid ejection method. For example, the liquid ejection method may be a liquid ejection method using a liquid ejection device that ejects liquid onto a target object, the liquid ejection device ejecting the liquid using a head, changing the relative position of the target object and the head in response to a command using a variable mechanism, and controlling the head to eject the liquid at a plurality of ejection positions, which are positions of the head when ejecting the liquid from the head, while passing through a plurality of command positions, which are positions corresponding to the command. The control unit controls the change of the relative position using the variable mechanism so that an ejection distance, which is the distance between the target object surface and the head in a normal direction to the target object surface, is non-uniform at at least some of the plurality of ejection positions. Such a liquid ejection method may achieve the same effects as the liquid ejection device described above.

[0097] The embodiments also include a program. For example, the program causes a liquid ejection device that ejects liquid onto a target object to execute the following process: a head ejects the liquid from a nozzle; a variable mechanism changes the relative position between the target object and the head in response to a command; a control unit controls the head to eject the liquid at multiple ejection positions, which are positions corresponding to the command, while passing through multiple command positions, and the control unit controls the variable mechanism to change the relative position so that an ejection distance, which is the distance between the target object surface and the head in a normal direction to the target object surface, is non-uniform at at least some of the multiple ejection positions. Such a program can achieve the same effects as the liquid ejection device described above.

[0098] Each function of the embodiments can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to perform each function by software, such as a processor implemented by an electronic circuit, as well as devices such as an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), and conventional circuit modules designed to perform each function described above. [Explanation of symbols]

[0099] 1a Head 100 Housing 101 Supply port 102 Collection Port 103 Connector 110 Dispensing Module 111 nozzle plate 121 nozzle 2 Variable mechanism 3. Control Unit 10 Liquid dispensing device 31 CPU 32 ROM 33 RAM 34 HDD / SSD 35 connection interface 36 Communication I / F 301 Communications Department 302 Input / output section 303 Command information generation unit 304 Thinning section 305 Verification Department 306 Command Department 307 Discharge control section 200 objects 200a, 200a1, 200a2 normal direction B System Bus Ec position signal Sn Sync signal Ck interval signal Hc, Hc_n1, Hc_n2, Hc_n3 drive signal Od Shape Information P, P1, P2 discharge position Q liquid Rc drive command d, d0, d1, d2 Discharge distance A Relative angle An minimum angle Ax maximum angle dn Minimum distance dx max distance e Discharge interval Td, Td1, Td2, Td3 Command position [Prior art documents] [Patent documents]

[0100] [Patent Document 1] International Publication No. 2015 / 025400

Claims

1. A liquid ejection device that ejects a liquid onto a target, a head that ejects the liquid; a variable mechanism capable of changing the relative position between the object and the head in response to a command; a control unit that controls the head so that the liquid is ejected at a plurality of ejection positions that are positions of the head when the liquid is ejected from the head, while the head passes through a plurality of command positions that are positions corresponding to the command, the control unit controls the change of the relative position by the variable mechanism so that a discharge distance, which is a distance between the surface of the object and the head in a normal direction of the surface of the object, is non-uniform at least in part of the plurality of discharge positions; The control unit thins out some of the plurality of command positions obtained at predetermined intervals based on the discharge distance.

2. The liquid ejection device according to claim 1 , wherein the control unit thins out some of the plurality of command positions when the ejection distance at each of the plurality of ejection positions is equal to or greater than a predetermined minimum distance and equal to or less than a predetermined maximum distance.

3. the head has a plurality of nozzles that eject the liquid, 3. The liquid ejection device according to claim 1, wherein the control unit thins out some of the plurality of command positions obtained at predetermined intervals based on the ejection distance for each of the plurality of nozzles.

4. the variable mechanism can further change a relative angle between the object and the head, The liquid ejection device according to claim 1 , wherein the control unit changes at least one of the relative positions and the relative angles so that the ejection distances are non-uniform at least in part of the plurality of command positions.

5. The liquid ejection device according to claim 4 , wherein the control unit thins out some of the plurality of command positions obtained at predetermined intervals based on the relative angle.

6. The liquid ejection device according to claim 5 , wherein the control unit thins out some of the plurality of command positions when the relative angle at each of the plurality of ejection positions is equal to or greater than a predetermined minimum angle and equal to or less than a predetermined maximum angle.

7. the head has a plurality of nozzles that eject the liquid, The liquid ejection device according to claim 4 , wherein the control unit thins out some of the plurality of command positions obtained at predetermined intervals based on the relative angle for each of the plurality of nozzles.

8. A liquid ejection method using a liquid ejection device that ejects a liquid onto a target, the liquid ejection device comprising: The liquid is ejected by a head, a variable mechanism for changing the relative position between the object and the head in response to a command; a control unit controls the head so that the head passes through a plurality of command positions that are positions corresponding to the command, and ejects the liquid at a plurality of ejection positions that are positions of the head when the liquid is ejected from the head; the control unit controls the change of the relative position by the variable mechanism so that a discharge distance, which is a distance between the surface of the object and the head in a normal direction of the surface of the object, is non-uniform at least in part of the plurality of discharge positions; The liquid ejection method, wherein the control unit thins out some of the plurality of command positions obtained at predetermined intervals based on the ejection distance.

9. A program to be executed by a liquid ejection device that ejects a liquid onto a target, The liquid is ejected from a nozzle by a head, a variable mechanism for changing the relative position between the object and the head in response to a command; a control unit controls the head to eject the liquid at a plurality of ejection positions that are positions of the head when ejecting the liquid from the head while the head passes through a plurality of command positions that are positions corresponding to the command; the control unit controls the change of the relative position by the variable mechanism so that a discharge distance, which is a distance between the surface of the object and the head in a normal direction of the surface of the object, is non-uniform at least in part of the plurality of discharge positions; the control unit thins out some of the plurality of command positions obtained at predetermined intervals based on the discharge distance. A program that causes the liquid ejection device to execute a process.

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