Liquid ejection device, control device, liquid ejection system, liquid ejection method, and program

Abstract

To provide a liquid discharge device that can form a film having excellent uniformity.SOLUTION: A liquid discharge device according to one embodiment of the present invention, which forms a film on a surface of an object with liquid, comprises a head that discharges liquid from each of a plurality of nozzles, a driving mechanism that at least moves the head and the object relatively, and a control part that controls discharging of the liquid by the head. The control part determines a liquid discharge amount that is an amount of the discharged liquid, on the basis of a scattering angle formed by a scattering direction of the liquid discharged from each of the plurality of nozzles and a normal direction of the surface of the object.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] 2. Description of the Related Art Liquid ejection devices that form a film on the surface of an object using a liquid are known in the art, and are used for purposes such as coating the surface of the object.

[0003] A liquid ejection device has been disclosed that ejects liquid onto an object having a curved surface at a timing corresponding to a printing speed obtained based on the distance between ejection positions along the relative movement trajectory between the head and the object and the relative movement speed (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] A liquid ejection device is required to form a film with excellent uniformity.

[0005] An object of the present invention is to provide a liquid ejection apparatus capable of forming a film with excellent uniformity. [Means for solving the problem]

[0006] A liquid ejection device according to one aspect of the present invention is a liquid ejection device that forms a film using liquid on the surface of an object, and includes a head that ejects the liquid from each of a plurality of nozzles, a drive mechanism that moves the head and the object at least relatively, and a control unit that controls the ejection of the liquid by the head, and the control unit determines a liquid ejection amount, which is the amount of liquid to be ejected, based on a flight angle that is the angle between the flight direction of the liquid ejected from each of the plurality of nozzles and the normal direction of the surface of the object. The drive mechanism changes a head angle, which is an angle between the flight direction and the direction of gravity, and the control unit determines the liquid ejection amount based on the flight angle, an object distance, which is a distance between each of the plurality of nozzles and the object, and the head angle. do. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a liquid ejection apparatus capable of forming a film with excellent uniformity. [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 an embodiment; [Figure 2] 1 is a block diagram illustrating an example of the overall configuration of a liquid ejection device according to an embodiment. [Figure 3] FIG. 2 is a perspective view illustrating the configuration of a head according to an embodiment. [Figure 4] FIG. 4 is a cross-sectional view of the head taken along plane S1 in FIG. 3. [Figure 5] 5A and 5B are diagrams for explaining the heads, where FIG. 5A is a diagram showing a piezoelectric drive type head and FIG. 5B is a diagram showing a valve jet type head. [Figure 6] FIG. 2 is a block diagram of an example of a hardware configuration of a control unit. [Figure 7] 3 is a block diagram illustrating the functional configuration of a control unit according to the first embodiment. FIG. [Figure 8] 8A and 8B are diagrams showing a method for determining a liquid ejection amount according to the first embodiment, where FIG. 8A shows the case where the flight angle is 0 degrees, and FIG. 8B shows the case where the flight angle is θ. [Figure 9] 9A and 9B are diagrams showing a method for determining a liquid ejection timing according to the first embodiment, in which FIG. 9A is a diagram showing division of a relative movement trajectory, and FIG. 9B is a diagram showing a target distance. [Figure 10] 10(a) and 10(d) are timing diagrams showing an example of processing by the control unit according to the first embodiment, in which FIG. 10(a) is a diagram showing the relative movement distance, FIG. 10(b) is a diagram showing the pulse signal, FIG. 10(c) is a diagram showing one nozzle and the ejection timing, and FIG. 10(d) is a diagram showing the ejection timing of another nozzle. [Figure 11] 4 is a flowchart showing an example of processing by a control unit according to the first embodiment. FIG. [Figure 12] FIG. 10 is a block diagram illustrating the functional configuration of a control unit according to a second embodiment. [Figure 13] 10A and 10B are diagrams illustrating a method for determining a liquid ejection amount according to a second embodiment. [Figure 14] 14A and 14B are diagrams showing a method for determining the liquid ejection timing according to the second embodiment, in which FIG. 14A shows the relative movement start position, FIG. 14B shows the ideal impact position, FIG. 14C shows the start impact position, and FIG. 14D shows the relative movement end position. [Figure 15] FIG. 10 is a flowchart illustrating an example of processing by a control unit 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] [Embodiment] <Example of overall configuration of liquid ejection device 10> The overall configuration of a liquid ejection device 10 will be described with reference to Figures 1 and 2. Figures 1 and 2 are diagrams illustrating the overall configuration of a liquid ejection device 10 according to an embodiment, 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 control unit 1, a drive mechanism 2, and a head 3. The liquid ejection device 10 is a coating device that applies a liquid ejected from the head 3 by an inkjet method to the surface of the object 200, thereby coating the surface of the object 200. The liquid 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 aircraft. Here, 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, in this embodiment, the surface of the object 200 is a curved surface having a curvature, but may also be a flat surface.

[0013] The control unit 1 is an example of a control device constructed using, for example, a PC (Personal Computer) or the like, and controls the ejection of liquid by the head 3. The control unit 1 is connected to the drive mechanism 2 and the head 3 via wired or wireless communication so that they can communicate with each other. Based on shape information Od and coating area information Pd, the control unit 1 outputs a drive command Rc to the drive mechanism 2 to cause the drive mechanism 2 to move the head 3, and outputs a drive signal Hc to the head 3 to eject liquid from the head 3. The shape information Od is shape information of the object 200 transmitted from an external device such as an external PC. The coating area information Pd is information corresponding to the area of ​​the surface of the object 200 to be painted.

[0014] The drive mechanism 2 is, for example, a robot arm capable of multi-axis drive, which moves the head 3 and the target object 200 relative to one another. The drive mechanism 2 moves the held head 3 to a desired position in three-dimensional space. By driving the drive mechanism 2, the liquid discharge device 10 can apply the liquid discharged from the head 3 to a desired position on the target object 200.

[0015] The driving mechanism is not limited to a robot arm, but may be configured with a stage that can move linearly in three axial directions, etc. Also, the target object 200 may be moved without moving the head 3, or both the head 3 and the target object 200 may be moved.

[0016] <Head 3 configuration example> 3 and 4 are diagrams illustrating the configuration of the head 3. Fig. 3 is a perspective view, and Fig. 4 is a cross-sectional view of the head 3 taken along plane S1 in Fig. 3.

[0017] The head 3 has a plurality of ejection modules 310 arranged in one or more rows within a housing 300 .

[0018] The head 3 has a supply port 301 and a recovery port 302. The supply port 301 supplies pressurized liquid from the outside to the ejection module 310, and the recovery port 302 discharges liquid that has not been ejected to the outside. The housing 300 also has a connector 303.

[0019] The ejection module 310 has a nozzle plate 311 equipped with nozzles 321 that eject liquid, a flow path 322 that communicates with the nozzles 321 and supplies pressurized liquid, and a piezoelectric member 324 that drives a needle-shaped valve body that opens and closes the nozzles 321.

[0020] Nozzle plate 311 is joined to housing 300. Flow path 322 is a flow path common to multiple ejection modules 310 provided in housing 300, and supplies pressurized ink from supply port 301 and discharges liquid from recovery port 302. Note that while liquid is being ejected onto target object 200, it is not necessary to temporarily suspend discharge of liquid from recovery port 302 so as not to reduce the efficiency of liquid ejection from nozzle 321.

[0021] The head 3 is a valve jet type head that ejects liquid from each of the multiple nozzles 321 onto the target object 200 by individually opening and closing the multiple nozzles 321. Here, Fig. 5 is a diagram for explaining the head, Fig. 5(a) is a diagram showing a piezoelectric drive type head 3x, and Fig. 5(b) is a diagram showing a valve jet type head 3. Fig. 5 is a plan view of each head viewed from the side from which the liquid is ejected.

[0022] The piezoelectric head 3x ejects liquid from nozzles 321x formed in a nozzle plate 311x by mechanically pushing out liquid from a liquid chamber of the piezoelectric head 3x using a piezoelectric element. Because it is manufactured using a piezoelectric element, many nozzles can be provided at high density, making it possible to draw fine image patterns with high quality.

[0023] The valve jet head 3 maintains high pressure on the liquid in the liquid chamber of the head 3, and ejects the liquid by opening and closing the valve of each nozzle 321. Compared to the piezoelectric drive head 3x, the head 3 has fewer nozzles per head, and ejects a larger amount of liquid per nozzle. Therefore, compared to the piezoelectric drive head 3x, it is easier to control the nozzles individually.

[0024] However, the liquid ejection device 10 according to this embodiment is not limited to the valve jet type head 3, and may use a piezoelectric drive type head 3x.

[0025] <Configuration example of control unit 1> (Example of hardware configuration) 6 is a block diagram illustrating an example of the hardware configuration of the control unit 1. The control unit 1 has a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a HDD (Hard Disk Drive) / SSD (Solid State Drive) 14, a connection I / F (Interface) 15, and a communication I / F 16. These are electrically connected to each other via a system bus B.

[0026] The CPU 11 uses the RAM 13 as a work area and executes programs stored in the ROM 12 to control the overall operation of the control unit 1.

[0027] The ROM 12 is a non-volatile memory that stores programs and other fixed data for controlling the recording operation and the like of the CPU 11. The RAM 13 is a volatile memory that temporarily stores various types of data.

[0028] The HDD / SSD 14 is a non-volatile memory that can store information such as painted area information Pd and shape information Od of the body of the object 200. The information stored in the HDD / SSD 14 may be read by the CPU 11 and used when the program is executed.

[0029] The connection I / F 15 is an interface for connecting to external devices, such as the drive mechanism 2 and the head 3. The communication I / F 16 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.

[0030] [First embodiment] (Example of functional configuration of control unit 1) 7 is a block diagram illustrating the functional configuration of the control unit 1 according to the first embodiment. The control unit 1 includes a communication unit 101, an input / output unit 102, a drive command unit 103, a flight angle acquisition unit 104, a discharge amount determination unit 105, a pulse signal generation unit 106, a relative movement trajectory acquisition unit 107, a discharge timing determination unit 108, and a discharge control unit 109.

[0031] The control unit 1 can realize the functions of the communication unit 101 by the communication I / F 16 etc., and the functions of the input / output unit 102 by the connection I / F 15 etc. The control unit 1 can also realize the functions of the drive command unit 103, flight angle acquisition unit 104, discharge amount determination unit 105, pulse signal generation unit 106, relative movement trajectory acquisition unit 107, discharge timing determination unit 108, and discharge control unit 109 by the CPU 11 executing a program stored in the ROM 12, etc.

[0032] The control unit 1 may have functional components other than those described above. Components other than the control unit 1 may also have some of the above functions of the control unit 1. Components other than the control unit 1 include the drive mechanism 2, the head 3, and an external PC. Some of the above functions of the control unit 1 may be realized by distributed processing of the control unit 1 and components other than the control unit 1. The control unit 1 may also realize at least some of the functions realized by the CPU 11 using electrical circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0033] The communication unit 101 controls the communication of signals and data between the control unit 1 and an external device such as an external PC. The input / output unit 102 controls the input / output of signals and data between the control unit 1 and the drive mechanism 2 and head 3.

[0034] The drive command unit 103 outputs a drive command Rc to the drive mechanism 2, causing the drive mechanism 2 to move the head 3 relatively.

[0035] The flight angle acquisition unit 104 acquires, by calculation, information on the flight angle θ, which is the angle between the flight direction of the liquid ejected from each of the multiple nozzles 321 and the normal direction to the surface of the object 200. For example, the flight angle acquisition unit 104 acquires, by calculation, information on the normal direction at each position on the surface of the object 200, based on shape information Od of the object 200, which has a curved surface. The flight angle acquisition unit 104 can then acquire information on the flight angle θ by calculating the angle between the flight direction of the liquid and the normal direction to the surface of the object 200.

[0036] The discharge amount determination unit 105 determines the liquid discharge amount M from each of the plurality of nozzles 321 in accordance with the flight angle θ acquired by the flight angle acquisition unit 104 , and outputs the determined amount to the discharge control unit 109 .

[0037] The pulse signal generating unit 106 generates a pulse signal k, which serves as a reference for the timing of ejecting liquid from each of the multiple nozzles 321, in accordance with the relative movement distance between the head 3 and the target object 200 caused by the driving mechanism 2, and outputs the pulse signal k to the ejection timing determining unit 108 and the ejection control unit 109.

[0038] For example, the pulse signal generating unit 106 generates the pulse signal k based on a detection signal output by a detector such as a rotary encoder or an acceleration sensor of the drive mechanism 2 in response to the operation of the drive mechanism 2. The timing at which the pulse signal k is generated may be determined in advance based on an operation simulation of the drive mechanism 2.

[0039] The relative movement trajectory acquisition unit 107 acquires information on the relative movement trajectory between the object 200 and the head 3 by calculation based on the painted area information Pd.

[0040] The ejection timing determination unit 108 determines the liquid ejection timing Δt based on the target distance, which is the distance between each of the plurality of nozzles 321 and the target object 200, and outputs the determined liquid ejection timing to the ejection control unit 109. For example, the ejection timing determination unit 108 calculates and acquires information on the target distance at each division point obtained by dividing the relative movement trajectory by the ejection interval, which is the interval between ejection positions along the relative movement direction between the plurality of nozzles 321 and the target object 200. The ejection timing determination unit 108 can determine the liquid ejection timing Δt based on this target distance.

[0041] The discharge control unit 109 outputs a drive signal Hc to the head 3 based on the coating area information Pd, the pulse signal k, the liquid discharge amount M, and the liquid discharge timing Δt, and causes each of the multiple nozzles 321 to discharge liquid.

[0042] <Method for determining liquid ejection amount M according to the first embodiment> 8A and 8B are diagrams illustrating a method for determining the liquid ejection amount M according to the first embodiment, with FIG. 8A showing the case where the flight angle is 0 degrees and FIG. 8B showing the case where the flight angle is θ. FIG. 8 shows how liquid is ejected in the direction of gravity from one nozzle 321 in the head 3. Flight direction 321a represents the direction in which the ejected liquid flies, and normal direction 200a represents the normal direction to the surface of the target object 200. In the example of FIG. 8, flight direction 321a is along the direction of gravity.

[0043] In FIG. 8(a), the normal direction 200a is aligned with the direction of gravity, and the flight angle θ is 0 degrees. On the other hand, in FIG. 8(b), the normal direction 200a is tilted by the flight angle θ with respect to the direction of gravity. If the normal direction 200a is tilted, the liquid that has landed on the surface of the target object 200 may move due to the action of gravity. The amount of liquid that moves increases as the flight angle θ increases. The movement of the liquid may change the film thickness formed on the surface of the target object 200, resulting in uneven coating. In this embodiment, the discharge amount determination unit 105 determines the liquid discharge amount M using the following equation, thereby correcting the film thickness that changes as the liquid moves. M=M0 / cos 2 θ (1) M0 represents the liquid ejection amount when the flight angle θ is 0 degrees.

[0044] <Method for determining liquid ejection timing Δt according to the first embodiment> 9A and 9B are diagrams showing a method for determining the liquid ejection timing Δt according to the first embodiment, in which Fig. 9A is a diagram showing the division of the relative movement trajectories, and Fig. 9B is a diagram showing the target distance. Fig. 9 shows the relative movement trajectories 401 and 402 of two nozzles out of the multiple nozzles 321 as arc-shaped curves.

[0045] First, as shown in FIG. 9(a), the ejection timing determination unit 108 divides each of the relative movement trajectories 401 and 402 by the ejection interval p.

[0046] 9(b), when a nozzle is located at each of the divided division points 403, the ejection timing determination unit 108 calculates the target distance d of the nozzle and divides it by a predetermined liquid ejection speed Vh. In this way, the ejection timing determination unit 108 can calculate the impact time, which is the time from when the liquid is ejected from the nozzle until it impacts the surface of the target 200.

[0047] Next, the ejection timing determination unit 108 determines the ejection start time by subtracting the impact time from the time when the nozzle is positioned at each divided point. The ejection timing determination unit 108 compares this ejection start time with the pulse signal k to determine the liquid ejection timing Δt.

[0048] As a result, the control unit 1 can determine the liquid ejection timing Δt according to the target distance d.

[0049] Here, pulse signal k is a signal that is generated each time the nozzle 321 moves an amount smaller than the ejection interval p (for example, half the ejection interval p). Each time pulse signal k is generated, nozzle 321 ejects a maximum of once. However, it is also possible to prevent ejection from nozzle 321 even when pulse signal k is generated.

[0050] The reason why the generation of pulse signal k is set to a value smaller than the ejection interval is because the head 3 uses multiple nozzles 321. Pulse signal k is generated based on the moving distance of the center of the drive mechanism 2. If the relative moving distance of the drive mechanism 2 is L_1 [m] and the ejection interval is p [m], the control unit 1 can achieve the ejection interval p by generating pulse signal k L_1 / p [times].

[0051] When the head 3 has multiple nozzles 321, the relative movement distance varies for each of the multiple nozzles 321. For example, when the head 3 moves in a curved line, an outer ring difference occurs in the relative movement distance L_2 [m] of the nozzles at the end farthest from the center of the multiple nozzles 321, and L_2 > L_1. As a result, it becomes impossible to achieve the ejection interval p for the nozzles at the end with a pulse signal k of L_1 / p [times]. For example, the average ejection interval for the nozzles at the end is (L_2 / L_1) × p > p. In such a case, the control unit 1 can achieve the ejection interval p by generating a pulse signal k every time the head 3 moves relatively a distance 0.5 times the ejection interval p, as long as L_2 does not exceed 2L_1.

[0052] <Example of processing by control unit 1> Fig. 10 is a timing chart illustrating processing by the control unit 1. Fig. 10(a) is a diagram showing the relative movement distance L of the head 3, Fig. 10(b) is a diagram showing the pulse signal k, Fig. 10(c) is a diagram showing the ejection timing of nozzle 321A out of the multiple nozzles 321, and Fig. 10(d) is a diagram showing the ejection timing of nozzle 321B out of the multiple nozzles 321. The time axes in Figs. 10(a) to 10(d) correspond to each other.

[0053] When the head 3 moves relatively as shown in FIG. 10(a), a pulse signal k is generated at predetermined times t1, t2, t3, t4 and t5 as shown in FIG. 10(b).

[0054] As shown in Figure 10(c), in nozzle 321A, liquid ejection timing Δt11 is determined for pulse signal k at time t1, liquid ejection timing Δt12 for pulse signal k at time t2, liquid ejection timing Δt13 for pulse signal k at time t3, liquid ejection timing Δt14 for pulse signal k at time t4, and liquid ejection timing Δt15 for pulse signal k at time t5, and timing signal Ts indicating each timing is generated.

[0055] Also, the liquid ejection period Ts in FIG. 11 ~Ts14 corresponds to the liquid ejection amount according to the timing signal Ts at times t1, t2, t3, t4 and t5. The period of the High state of the timing signal Ts corresponds to the ejection period, and the longer the High state period, the greater the liquid ejection amount. In other words, 11 The liquid discharge amount M corresponding to 11 , liquid discharge period Ts 12 The liquid discharge amount M corresponding to 12 , liquid discharge period Ts 13 The liquid discharge amount M corresponding to 13 , liquid discharge period Ts 14 The liquid discharge amount M corresponding to 14 Then, M 11 <M 12 <M 13 <M 14 are in a relationship.

[0056] As shown in Figure 10(d), in nozzle 321B, liquid ejection timing Δt21 is determined for pulse signal k at time t1, liquid ejection timing Δt22 for pulse signal k at time t2, liquid ejection timing Δt23 for pulse signal k at time t3, liquid ejection timing Δt24 for pulse signal k at time t4, and liquid ejection timing Δt25 for pulse signal k at time t5, and timing signals Ts indicating each timing are generated.

[0057] Also, the liquid ejection period Ts in FIG. 21 ~Ts 24 corresponds to the liquid ejection amount according to the timing signal Ts at each of the times t1, t2, t3, t4 and t5. 21 The liquid discharge amount M corresponding to 21 , liquid discharge period Ts 22 The liquid discharge amount M corresponding to 22 , liquid discharge period Ts 23 The liquid discharge amount M corresponding to 23 , liquid discharge period Ts 24 The liquid discharge amount M corresponding to 24 Then, M21 <M 22 <M 23 <M 24 are in a relationship.

[0058] Because pulse signal k is generated in accordance with the movement of the head 3, the timing of its generation is common to all of the multiple nozzles 321. In this embodiment, for each nozzle, the delay time for one pulse signal k is determined as the liquid ejection timing Δt. After one pulse signal k is generated, each of the multiple nozzles 321 waits for the determined liquid ejection timing Δt before ejecting liquid.

[0059] Fig. 11 is a flowchart illustrating the operation of the control unit 1. For example, the control unit 1 starts the process of Fig. 11 when shape information Od and painting area information Pd are input from an external PC or the like.

[0060] First, in step S111, the control unit 1 acquires information on the normal direction 200a by calculation using the flight angle acquisition unit 104 based on the shape information Od of the object 200, and acquires the flight angle θ by calculating the angle between the flight direction 321a of the liquid and the normal direction 200a.

[0061] Next, in step S112, the control unit 1 determines, by the discharge amount determination unit 105, information on the liquid discharge amount M from each of the multiple nozzles 321 by calculation, according to the flight angle θ acquired by the flight angle acquisition unit 104, and outputs it to the discharge control unit 109.

[0062] Next, in step S113, the control unit 1 causes the pulse signal generating unit 106 to generate a pulse signal k, which serves as a reference for the timing of ejecting liquid from each of the multiple nozzles 321, in accordance with the relative movement distance L between the head 3 and the target object 200 caused by the driving mechanism 2, and outputs the pulse signal k to the ejection timing determination unit 108 and the ejection control unit 109.

[0063] Subsequently, in step S114, the control unit 1 causes the relative movement trajectory acquisition unit 107 to acquire information on the relative movement trajectory between the object 200 and the head 3 by calculation based on the painted area information Pd.

[0064] Subsequently, in step S115, the control unit 1 causes the ejection timing determination unit 108 to acquire, by calculation, information on the target distance d at each division point obtained by dividing the relative movement trajectory by the ejection intervals of each of the plurality of nozzles 321.

[0065] Subsequently, in step S116, the control unit 1 determines the liquid ejection timing Δt based on the target distance d.

[0066] Next, in step S117, the control unit 1 outputs a drive signal Hc to the head 3 based on the coating area information Pd, the pulse signal k, the liquid ejection amount M, and the liquid ejection timing Δt via the ejection control unit 109, causing liquid to be ejected from each of the multiple nozzles 321.

[0067] Next, in step S118, the control unit 1 determines whether to end the process. For example, the control unit 1 can determine the end of the process depending on whether the process has been performed based on all the information in the shape information Od or the painted area information Pd.

[0068] If the control unit 1 determines in step S118 that the process should be ended (YES in step S118), it ends the process, and if it determines that the process should not be ended (NO in step S118), it performs the process from step S111 onwards again.

[0069] In this way, the control unit 1 can control the ejection of the liquid in accordance with the shape information Od and the coating area information Pd.

[0070] <Effects of the liquid ejection device 10> As described above, the liquid ejection device 10 has the head 3, the drive mechanism 2, and the control unit 1, and the control unit 1 determines the liquid ejection amount M based on the flight angle θ, which is the angle between the flight direction 321a of the liquid ejected from each of the multiple nozzles 321 and the normal direction 200a to the surface of the target object 200. For example, the control unit 1 determines the liquid ejection amount M at the flight angle θ using the above-mentioned formula (1).

[0071] If the surface of the object 200 is tilted, such as when the object 200 has a curved surface, the liquid that has landed on the surface of the object 200 will move due to the action of gravity. This movement of the liquid may change the film thickness formed on the surface of the object 200, resulting in uneven coating. In this embodiment, by determining the liquid ejection amount M based on the flight angle θ, it is possible to increase the liquid ejection amount in areas where the film thickness becomes thinner due to the movement of the liquid. As a result, the film thickness formed on the surface of the object 200 can be corrected, and a liquid ejection device 10 capable of forming a film with excellent uniformity can be provided.

[0072] In this embodiment, the control unit 1 determines the liquid ejection timing Δt based on the target distance d. For example, the control unit 1 determines the liquid ejection timing Δt from the target distance d at each division point obtained by dividing the relative movement trajectory between the nozzle 321 and the target 200 by the ejection interval p.

[0073] When the target 200 has a curved surface, the target distance d differs for each of the multiple nozzles 321. Because the head 3 and the target 200 move relative to each other, differences in the target distance d cause deviations in the landing positions of the liquid on the surface of the target 200 from the desired positions. In this embodiment, by determining the liquid ejection timing Δt, the landing positions of each of the multiple nozzles 321 can be made different depending on the target distance d, and the deviations in the landing positions can be corrected. This allows the liquid to land at the desired positions on the surface of the target 200, and a desired film with excellent uniformity can be formed on the surface of the target 200.

[0074] Furthermore, in this embodiment, the head 3 discharges liquid from each of the multiple nozzles 321 onto the target object 200 by opening and closing the multiple nozzles 321 individually. Compared to a piezoelectric drive type head or the like, the number of nozzles per head can be reduced and the liquid discharge amount M per nozzle can be increased. This makes it easier to individually control the multiple nozzles 321 and allows for efficient film formation.

[0075] Although the present embodiment exemplifies a liquid ejection device 10, the same effects as those of the liquid ejection device 10 can also be obtained in a liquid ejection system having a control device with the functions of the control unit 1, a drive mechanism 2, and a liquid ejection device having a head 3.

[0076] [Second embodiment] Next, a control unit 1a according to the second embodiment will be described. Note that the same components as those in the first embodiment are given the same reference numerals, and redundant description will be omitted where appropriate.

[0077] 12 is a block diagram illustrating the functional configuration of the control unit 1a. The control unit 1a has a head angle acquisition unit 110, a storage unit 111, a discharge amount determination unit 105a, a relative movement speed acquisition unit 112, and a discharge timing determination unit 108a.

[0078] The control unit 1a can realize the functions of the storage unit 111 by the HDD / SSD 14. The control unit 1a can also realize the functions of the head angle acquisition unit 110, the discharge amount determination unit 105a, the relative movement speed acquisition unit 112, and the discharge timing determination unit 108a by causing the CPU 11 to execute a program stored in the ROM 12, etc.

[0079] Note that components other than the control unit 1a may have some of the above-mentioned functions of the control unit 1a, or some of the above-mentioned functions may be realized by distributed processing between the control unit 1a and components other than the control unit 1a. Furthermore, the control unit 1a may realize at least some of the functions realized by the CPU 11 using an electric circuit such as an ASIC or FPGA.

[0080] The head angle acquisition unit 110 acquires, by calculation, information on the head angle φ, which is the angle between the direction of gravity and the flight direction 321a of the nozzle 321, which is changed by the drive mechanism 2. For example, the head angle acquisition unit 110 can acquire information on the head angle φ based on a detection signal output from a detection unit such as a rotary encoder provided in the drive mechanism 2.

[0081] The storage unit 111 stores correspondence information 113, which is information indicating the correspondence between the flight angle θ, the target distance d, and the head angle φ, or information related to the correspondence. The correspondence information 113 can be determined in advance through a preliminary experiment or the like.

[0082] The discharge amount determination unit 105a determines the liquid discharge amount M based on the flight angle θ, the target distance d of the multiple nozzles 321, and the head angle φ, and outputs the liquid discharge amount M to the discharge control unit 109. For example, the discharge amount determination unit 105a can determine the liquid discharge amount M by referring to the correspondence information 113 stored in the storage unit 111.

[0083] The relative movement speed acquisition unit 112 acquires, by calculation, information on the relative movement speed v between the head 3 and the target object 200. The relative movement speed acquisition unit 112 can acquire the information on the relative movement speed v based on a detection signal output from a detection unit such as a rotary encoder included in the drive mechanism 2.

[0084] The ejection timing determination unit 108 a determines the liquid ejection timing Δt based on the target distance d and the relative movement speed v between the head 3 and the target 200 , and outputs it to the ejection control unit 109 .

[0085] <Method for determining liquid ejection amount M according to the second embodiment> FIG. 13 is a diagram illustrating a method for determining the liquid ejection amount M according to the second embodiment, and is a diagram illustrating an example of the correspondence information 113.

[0086] 13, the head angle φ is shown as a row, and the target distance d and flight angle θ are shown as columns. A1_1, A2_1, . . . , C4_13, and C5_13 each represent the liquid ejection amount M.

[0087] The discharge amount determination unit 105a can determine the liquid discharge amount M by referring to the correspondence information 113 based on the input head angle φ, target distance d, and flight angle θ. In this case, the smaller the resolution of each of the head angle φ, target distance d, and flight angle θ, the more precisely the liquid discharge amount M can be determined, but on the other hand, the amount of data in the correspondence information 113 increases. For this reason, it is preferable that the discharge amount determination unit 105a interpolates the liquid discharge amount M at or below the resolution of each of the head angle φ, target distance d, and flight angle θ by interpolation or the like. An example of this calculation method is shown below.

[0088] For example, a case will be described in which the liquid ejection amount M is obtained when the target distance d is 13 [mm], the flight angle θ is 35 [degrees], and the head angle φ is 50 [degrees].

[0089] First, the discharge amount determination unit 105a calculates the liquid discharge amount M11 when the target distance d is 10 [mm], the flight angle θ is 30 [degrees], and the head angle φ is 50 [degrees], using the following formula. M11={1-(60-50) / (60-45)}×A3_4+(60-50) / (60-45)×A3_5

[0090] Next, the discharge amount determination unit 105a calculates the liquid discharge amount M12 when the target distance d is 10 [mm], the flight angle θ is 45 [degrees], and the head angle φ is 50 [degrees] using the following formula. M12={1-(60-50) / (60-45)}×A4_4+(60-50) / (60-45)×A4_5

[0091] Next, the discharge amount determination unit 105a calculates the liquid discharge amount M13 when the target distance d is 20 [mm], the flight angle θ is 30 [degrees], and the head angle φ is 50 [degrees] using the following formula. M13={1-(60-50) / (60-45)}×B3_4+(60-50) / (60-45)×B3_5

[0092] Next, the discharge amount determination unit 105a calculates the liquid discharge amount M13 when the target distance d is 20 [mm], the flight angle θ is 45 [degrees], and the head angle φ is 50 [degrees], using the following formula. M14={1-(60-50) / (60-45)}×B4_4+(60-50) / (60-45)×B4_5

[0093] Next, the discharge amount determination unit 105a calculates the liquid discharge amount M21 when the target distance d is 10 [mm], the flight angle θ is 35 [degrees], and the head angle φ is 50 [degrees] using the following formula. M21={1-(35-30) / (45-30)}×M11+(35-30) / (45-30)×M12

[0094] Next, the discharge amount determination unit 105a calculates the liquid discharge amount M22 when the target distance d is 20 [mm], the flight angle θ is 35 [degrees], and the head angle φ is 50 [degrees] using the following formula. M22={1-(35-30) / (45-30)}M13+(35-30) / (45-30)×M14

[0095] Finally, the discharge amount determination unit 105a calculates the liquid discharge amount M22 when the target distance d is 13 [mm], the flight angle θ is 35 [degrees], and the head angle φ is 50 [degrees] using the following formula. V={1-(13-10) / (20-10)}×V21+(13-10) / (20-10)×V22

[0096] In this way, the discharge amount determination unit 105a can determine the liquid discharge amount M at or below the resolution of each of the head angle φ, the target distance d, and the flight angle θ by interpolation calculation.

[0097] <Method for determining liquid ejection timing Δt according to the second embodiment> 14A and 14B are diagrams illustrating a method for determining the liquid ejection timing Δt according to the second embodiment, in which Fig. 14A shows the relative movement start position, Fig. 14B shows the ideal landing position, Fig. 14C shows the starting landing position, and Fig. 14D shows the relative movement end position.

[0098] Here, if the relative movement speed v between the head 3 and the target object 200 is large, the error in determining the liquid ejection timing Δt may become large. Therefore, the ejection timing determination unit 108a determines the liquid ejection timing Δt based on the target distance d and the relative movement speed v.

[0099] When the relative movement velocity v is large, the velocity vector of the ejected liquid is expressed as a resultant vector of the ejected droplet velocity vector and the relative movement velocity vector. Furthermore, by including not only the relative movement velocity v but also the head angle φ in the calculation formula, it is possible to correct for deviations in the landing position due to the effect of gravity.

[0100] First, as shown in FIG. 14(a), a relative movement start position 404 and a relative movement end position 405 are determined on the relative movement trajectory of the nozzle 321.

[0101] Next, the initial landing position 406 of the liquid on the surface of the target object 200 at the relative movement start position 404 is calculated.

[0102] Next, as shown in FIG. 14B, an ideal landing position 407 is calculated by shifting the ejection interval p in the relative movement direction.

[0103] Next, as shown in Figure 14(c), an ideal nozzle 408 that ejects liquid at an ideal impact position 407 is identified, and the impact position of the liquid ejected from that nozzle is calculated. In this case, both the relative movement speed and the flight trajectory of the combined liquid are taken into consideration. The liquid ejection timing Δt can be determined by correlating the time at this impact position with the pulse signal.

[0104] <Example of processing by control unit 1a> Fig. 15 is a flowchart illustrating the processing by the control unit 1a. For example, the control unit 1a starts the processing of Fig. 15 when shape information Od and painting area information Pd are input from an external PC or the like. Note that duplicated explanations of steps that perform the same processing as in Fig. 11 will be omitted as appropriate.

[0105] First, the process of step S151 is the same as the process of step S111 in FIG.

[0106] Next, in step S152, the control unit 1a causes the head angle acquisition unit 110 to acquire information on the head angle φ formed by the flight direction 321a of the nozzle 321 changed by the drive mechanism 2 and the direction of gravity through calculation.

[0107] Subsequently, in step S153, the control unit 1a determines the liquid ejection amount M by the ejection amount determination unit 105a with reference to the correspondence information 113 based on the flight angle θ, the target distance d of each of the plurality of nozzles 321, and the head angle φ.

[0108] Subsequently, the processes from step S154 to step S156 are the same as the processes from step S113 to step S115 in FIG.

[0109] Subsequently, in step S157, the control unit 1a causes the relative movement speed acquisition unit 112 to acquire information on the relative movement speed v between the head 3 and the target object 200 by calculation.

[0110] Subsequently, in step S158, the control unit 1a determines the liquid ejection timing Δt based on the target distance d and the relative movement speed v between the head 3 and the target object 200 by the ejection timing determination unit 108a.

[0111] Subsequently, the processes from step S159 to step S160 are the same as the processes from step S117 to step S118 in FIG.

[0112] In this way, the control unit 1a can control the discharge of the liquid in accordance with the shape information Od and the coating area information Pd.

[0113] <Function and effect of control unit 1a> As described above, in this embodiment, the drive mechanism 2 changes the head angle φ formed by the flight direction 321a of the nozzles 321 and the direction of gravity, and the control unit 1a determines the liquid ejection amount M based on the flight angle θ, the target distance d of each of the multiple nozzles 321, and the head angle φ. This makes it possible to accurately determine the liquid ejection amount M even when the head angle φ of the head 3 is changed by the drive mechanism 2.

[0114] Furthermore, in this embodiment, the liquid ejection timing Δt is determined based on the target distance d and the relative movement speed v between the head 3 and the target object 200. This allows the liquid ejection timing Δt to be determined accurately even when the relative movement speed v is high.

[0115] 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.

[0116] In the embodiment, the liquid ejected from the head 3 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, in inkjet inks, coating materials, surface treatment solutions, liquids for forming components of electronic elements or light-emitting elements, or electronic circuit resist patterns, and material liquids for 3D modeling.

[0117] 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.

[0118] The embodiments also include a liquid ejection method. For example, the liquid ejection method is a liquid ejection method using a liquid ejection device that forms a film on the surface of an object using liquid, in which the liquid ejection device ejects the liquid from each of a plurality of nozzles using a head, moves the head and the object at least relatively using a drive mechanism, controls the ejection of the liquid from the head using a control unit, and the control unit determines the liquid ejection amount, which is the amount of liquid ejected, based on the flight angle, which is the angle between the flight direction of the liquid ejected from each of the plurality of nozzles and the normal direction to the surface of the object. Such a liquid ejection method can achieve the same effects as the liquid ejection device described above.

[0119] The embodiments also include a program. For example, the program may be executed by a liquid ejection device that forms a film on the surface of an object using a liquid, the program causing a head to eject the liquid from each of a plurality of nozzles, a drive mechanism to move at least the head and the object relatively, a control unit to control the ejection of the liquid by the head, and the control unit to execute a process that determines a liquid ejection amount, which is the amount of liquid to be ejected, based on a flight angle, which is the angle between the flight direction of the liquid ejected from each of the plurality of nozzles and the normal direction to the surface of the object. Such a program may provide the same effects as the liquid ejection device described above.

[0120] 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]

[0121] 1. Control unit (an example of a control device) 10 Liquid dispensing device 11 CPU 12 ROM 13 RAM 14 HDD / SSD 15 Connection I / F 16 Communication I / F 101 Communications Department 102 Input / output section 103 Drive control unit 104 Flight angle acquisition section 105, 105a Discharge amount determining section 106 Pulse signal generator 107 Relative movement trajectory acquisition unit 108, 108a Discharge timing determination unit 109 Discharge control section 110 Head angle acquisition unit 111 Storage area 112 Relative movement speed acquisition unit 113 Compatibility Information 2. Drive mechanism 200 objects 200a Normal direction 3 heads 300 Housing 301 Supply Port 302 Collection Port 303 Connector 310 Dispensing Module 311 Nozzle plate 321 Nozzle 321a Flight direction 322 Channel 324 Piezoelectric Components 401, 402 Relative movement trajectory 403 Division point 404 Relative movement start position 405 Relative movement end position 406 Starting impact position 407 Ideal impact position 408 Ideal Nozzle B System Bus Od Shape Information Pd Paint Area Information Rc drive command Hc drive signal θ flight angle M, M0 liquid discharge amount k pulse signal L relative movement distance Δt Liquid discharge timing p Discharge interval d target distance t1, t2, t3, t4, t5 time Ts timing signal [Prior art documents] [Patent documents]

[0122] [Patent Document 1] Japanese Patent Application Publication No. 2021-088109

Claims

1. A liquid ejection device that forms a film on a surface of an object using a liquid, a head that ejects the liquid from each of a plurality of nozzles; a drive mechanism for at least relatively moving the head and the object; a control unit that controls the ejection of the liquid by the head, the control unit determines a liquid ejection amount, which is an amount of the liquid to be ejected, based on a flight angle, which is an angle between a flight direction of the liquid ejected from each of the plurality of nozzles and a normal direction to the surface of the target object; the drive mechanism changes a head angle, which is an angle between the flight direction and the direction of gravity, The control unit determines the liquid ejection amount based on the flight angle, a target distance which is the distance between the nozzle and the target for each of the plurality of nozzles, and the head angle.

2. The liquid ejection device according to claim 1 , wherein the control unit determines the liquid ejection amount M at the flight angle θ using the following formula: M = M0 / cos2θ (M0 represents the liquid ejection amount when the flight angle θ is 0 degrees.)

3. 3. The liquid ejection device according to claim 1, wherein the control unit determines a liquid ejection timing, which is a timing for ejecting the liquid, based on a target distance, which is a distance between each of the plurality of nozzles and the target.

4. The liquid ejection device according to claim 3, wherein the control unit determines the liquid ejection timing from the target distance at each division point obtained by dividing the relative movement trajectory between the nozzle and the target by an ejection interval, which is the distance between ejection positions along the relative movement direction between the head and the target.

5. 5. The liquid ejection apparatus according to claim 3, wherein the liquid ejection timing is determined based on the target distance and a relative movement speed between the head and the target.

6. A liquid ejection device for forming a film on the surface of an object using a liquid, a head that ejects the liquid from each of a plurality of nozzles; a drive mechanism for at least relatively moving the head and the object; a control unit that controls the ejection of the liquid by the head, the control unit determines a liquid ejection amount, which is an amount of the liquid to be ejected, based on a flight angle, which is an angle between a flight direction of the liquid ejected from each of the plurality of nozzles and a normal direction to the surface of the target object; The control unit determines a timing for ejecting the liquid based on a target distance, which is a distance between each of the plurality of nozzles and the target.

7. A liquid ejection device for forming a film on the surface of an object using a liquid, a head that ejects the liquid from each of a plurality of nozzles; a drive mechanism for at least relatively moving the head and the object; a control unit that controls the ejection of the liquid by the head, the control unit determines a liquid ejection amount, which is an amount of the liquid to be ejected, based on a flight angle, which is an angle between a flight direction of the liquid ejected from each of the plurality of nozzles and a normal direction to the surface of the target object; The control unit determines the timing of ejecting the liquid from a target distance, which is the distance between the nozzle and the target for each of the plurality of nozzles, at each division point obtained by dividing the relative movement trajectory between the nozzle and the target by an ejection interval, which is the distance between ejection positions along the relative movement direction between the head and the target.

8. A liquid ejection device for forming a film on the surface of an object using a liquid, a head that ejects the liquid from each of a plurality of nozzles; a drive mechanism for at least relatively moving the head and the object; a control unit that controls the ejection of the liquid by the head, the control unit determines a liquid ejection amount, which is an amount of the liquid to be ejected, based on a flight angle, which is an angle between a flight direction of the liquid ejected from each of the plurality of nozzles and a normal direction to the surface of the target object; A liquid ejection device that determines the timing to eject the liquid based on a target distance, which is the distance between each of the plurality of nozzles and the target, and a relative movement speed between the head and the target.

9. The liquid ejection device according to claim 1 , wherein the head ejects the liquid from each of the plurality of nozzles onto the target object by opening and closing the plurality of nozzles individually.

10. A control device for controlling ejection of liquid from a head that forms a film on a surface of an object using liquid ejected from each of a plurality of nozzles, a control device having a discharge amount determination unit that determines a liquid discharge amount, which is the amount of liquid to be discharged, based on a flight angle, which is the angle between the flight direction of the liquid discharged from each of the plurality of nozzles and the normal direction of the target surface.

11. a liquid ejection device having a head that ejects liquid from a plurality of nozzles onto a target; a drive mechanism for at least relatively moving the head and the object; a control device that controls the ejection of the liquid by the head, The control device determines the liquid ejection amount, which is the amount of liquid to be ejected, based on the flight angle, which is the angle between the flight direction of the liquid ejected from each of the multiple nozzles and the normal direction of the target surface.

12. A liquid ejection method using a liquid ejection device for forming a film on a surface of an object using a liquid, the liquid ejection device comprising: The head ejects the liquid from each of a plurality of nozzles, a drive mechanism for at least relatively moving the head and the object; a control unit controls the ejection of the liquid from the head; the control unit determines a liquid ejection amount, which is an amount of the liquid to be ejected, based on a flight angle, which is an angle between a flight direction of the liquid ejected from each of the plurality of nozzles and a normal direction to the surface of the target object; the drive mechanism changes a head angle, which is an angle between the flight direction and the direction of gravity, The control unit determines the liquid ejection amount based on the flight angle, a target distance which is the distance between the nozzle and the target for each of the plurality of nozzles, and the head angle.

13. A program to be executed by a liquid ejection device that forms a film on a surface of a target object using a liquid, The head ejects the liquid from each of a plurality of nozzles, a drive mechanism for at least relatively moving the head and the object; a control unit controls the ejection of the liquid from the head; the control unit determines a liquid ejection amount, which is an amount of the liquid to be ejected, based on a flight angle, which is an angle between a flight direction of the liquid ejected from each of the plurality of nozzles and a normal direction to the surface of the target object; the drive mechanism changes a head angle, which is an angle between the flight direction and the direction of gravity, the control unit determines the liquid ejection amount based on the flight angle, a target distance which is a distance between each of the plurality of nozzles and the target, and the head angle. A program that causes the liquid ejection device to execute a process.

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