Method for controlling a robot system and robot system

Abstract

To provide a control method and a robot system capable of performing high-quality printing. [Solution] The robot system control method uses a robot having a robot arm, a print head positioned on the robot arm and ejecting ink from a nozzle, and a barrier wall positioned parallel to the print head and positioned to protrude in the ejection direction from the nozzle in a plan view from a direction perpendicular to the direction of ink ejection. In an environment where airflow is present, the method prints on the object by ejecting ink from the nozzle toward the object at predetermined timings while moving the print head and the object relatively along a printing trajectory, while maintaining a posture in which the barrier wall is positioned upstream of the airflow relative to the nozzle.

Description

Technical Field

[0001] The present invention relates to a method for controlling a robot system and a robot system.

Background Art

[0002] Patent Document 1 describes a printing method for printing on an object using a robot. In such a printing method, a robot having a robot arm, a moving stage disposed at the tip of the robot arm, and a print head attached to the moving stage is used. With the robot arm stopped, the print head is moved relative to the object by the moving stage while ink is ejected from the print head to perform printing on the object. At this time, the movement range of the moving stage is set such that the printing range at a location with a large curvature of the object is smaller than that at a location with a small curvature.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the printing method of Patent Document 1, no consideration is given to the printing environment. Therefore, when printing in an environment where an air flow is generated, the landing position of the ink may shift due to a change in the ejection trajectory of the ink caused by the air flow, which may lead to a deterioration in print quality.

Means for Solving the Problems

[0005] The present invention provides a robot system control method that uses a robot comprising: a robot arm; a print head positioned on the robot arm and ejecting ink from a nozzle; and a barrier wall positioned parallel to the print head and, in a plan view from a direction perpendicular to the ink ejection direction, protruding further in the ejection direction than the nozzle. In an environment where airflow is present, printing is performed on the object by maintaining a position in which the barrier wall is located upstream of the airflow relative to the nozzle, while moving the print head and the object relative to each other along the printing trajectory, and ejecting the ink from the nozzle toward the object at a predetermined timing.

[0006] The robot system of the present invention comprises a robotic arm and The robot arm is equipped with a print head that ejects ink from a nozzle, The print head is arranged in parallel with the barrier wall, and in a plan view from a direction perpendicular to the ink ejection direction, the barrier wall is positioned to protrude further in the ejection direction than the nozzle, In an environment where airflow is present, printing is performed on the object by maintaining a position in which the barrier wall is located upstream of the airflow relative to the nozzle, while moving the print head and the object relative to each other along the printing trajectory, and ejecting the ink from the nozzle toward the object at a predetermined timing. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is an overall diagram of the robot system according to the first embodiment. [Figure 2] Figure 2 is a plan view showing the moving stage and print head of the robot shown in Figure 1. [Figure 3] Figure 3 is an exploded perspective view showing the print head. [Figure 4] Figure 4 is a perspective cross-sectional view showing the print head. [Figure 5] Figure 5 shows the print head moving along the print path. [Figure 6] Figure 6 is a plan view showing a modified example of the barrier wall. [Figure 7] Figure 7 is a plan view showing a modified example of the barrier wall. [Figure 8] Figure 8 shows how droplets adhere to the barrier wall. [Figure 9] Figure 9 shows a print head included in the robot system according to the second embodiment. [Figure 10] Figure 10 shows a modified example of a barrier wall. [Figure 11] Figure 11 shows a modified example of a barrier wall. [Figure 12] Figure 12 shows a print head of the robot system according to the third embodiment. [Modes for carrying out the invention]

[0008] The control method and robot system of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

[0009] <First Embodiment> Figure 1 is an overall view of the robot system according to the first embodiment. Figure 2 is a plan view showing the moving stage and print head of the robot shown in Figure 1. Figure 3 is an exploded perspective view showing the print head. Figure 4 is a perspective cross-sectional view showing the print head. Figure 5 shows the print head moving along the printing trajectory. Figures 6 and 7 are plan views showing modified examples of the barrier wall, respectively. Figure 8 shows the barrier wall with splashes adhering to it.

[0010] The robot system 1 shown in FIG. 1 is a printing system for performing high-quality printing on an object W in an environment where an air current C is generated. The environment where the air current C is generated is not particularly limited. For example, as shown in FIG. 1, printing may be performed while ventilating the printing chamber R so that harmful substances such as organic solvents contained in the ink (ink I described later) used for printing do not fill the printing chamber R. In such a case, for example, printing must be performed in a state where an air current C is generated from an air supply port (not shown) provided on the ceiling toward an exhaust port (not shown) provided on the floor. Hereinafter, this example will be used for explanation.

[0011] Such a robot system 1 includes a robot 2 that performs printing on an object W and a control device 9 that controls the driving of the robot 2. The robot 2 includes a robot body 3 having a robot arm 32, a moving stage 4 disposed at the tip of the robot arm 32, a printing head 5 disposed on the moving stage 4, an inertial sensor 6 disposed on the printing head 5, and a blocking wall 7 disposed on the printing head 5.

[0012] In such a robot system 1, while moving the printing head 5 along a printing trajectory Q with respect to the object W using the robot arm 32, printing operation on the object W is performed by discharging ink I from the printing head 5 at a predetermined timing. At this time, the blocking wall 7 is positioned on the upstream side (windward) of the air current C with respect to the printing head 5, and by blocking the air current C with the blocking wall 7, it is possible to suppress the air current C from colliding with the ink I flying toward the object W, and by suppressing landing deviation of the ink I and the like, high printing quality is achieved.

[0013] In the robot system 1 of the present embodiment, the robot arm 32 holds the printing head 5 and performs printing while moving the printing head 5 with respect to the object W fixed to a stage or the like. However, the present invention is not limited to this. For example, the object W may be held by another robot arm (not shown), and printing may be performed while moving both the printing head 5 and the object W.

[0014] ≪Robot Body 3≫ As shown in FIG. 1, the robot body 3 is a six-axis vertical articulated robot having six drive axes, and includes a base 31 fixed to a floor or the like, and a robot arm 32 rotatably connected to the base 31.

[0015] The robot arm 32 is configured such that six arms 321, 322, 323, 324, 325, and 326 are rotatably connected in this order from the base 31 side, and includes six joints J1, J2, J3, J4, J5, and J6. Specifically, the arm 321 is rotatably connected to the base 31 via the joint J1. The arm 322 is rotatably connected to the arm 321 via the joint J2. The arm 323 is rotatably connected to the arm 322 via the joint J3. The arm 324 is rotatably connected to the arm 323 via the joint J4. The arm 325 is rotatably connected to the arm 324 via the joint J5. The arm 326 is rotatably connected to the arm 325 via the joint J6.

[0016] Among the joints J1 to J6, the joints J2, J3, and J5 are bending joints, respectively, and the joints J1, J4, and J6 are torsion joints, respectively. Although not shown, drive mechanisms each including a motor, a speed reducer that decelerates the rotation of the motor to increase torque and outputs it, and an encoder that detects the amount of rotation of the joint are installed at the joints J1, J2, J3, J4, J5, and J6. By moving each of the joints J1, J2, J3, J4, J5, and J6 independently, the tip of the robot arm 32 can be moved in a desired direction at a predetermined posture and speed.

[0017] However, the configuration of the robot body 3 is not particularly limited. For example, the number of arms included in the robot arm 32 is not limited to six. Further, the robot body 3 may be a dual-arm robot, a horizontal articulated robot (scalar robot), or the like. Further, the robot body 3 may not be fixed to a mounting table, a floor, or the like and may be capable of self-running.

[0018] ≪Moving stage 4≫ As shown in Figure 1, the moving stage 4 is located at the tip of the robot arm 32, that is, on arm 326. The moving stage 4 is used for position correction of the print head 5, specifically for vibration cancellation of the print head 5. As shown in Figure 2, the moving stage 4 has a base 40 supported by arm 326, a movable stage 41 that is movable relative to the base 40, and a piezoelectric drive unit 42 that moves the movable stage 41 relative to the base 40.

[0019] Furthermore, the movable stage 41 includes a first stage 411 that moves linearly in a first direction A relative to the base 40, and a second stage 412 that moves linearly in a second direction B perpendicular to the first direction A relative to the first stage 411. The print head 5 is supported on the second stage 412.

[0020] Furthermore, the piezoelectric drive unit 42 includes a first stage drive unit 421 that moves the first stage 411 along a first direction A relative to the base unit 40, and a second stage drive unit 422 that moves the second stage 412 along a second direction B relative to the first stage 411. The first and second stage drive units 421 and 422 are each equipped with piezoelectric actuators that are driven by the expansion and contraction of piezoelectric elements due to the flow of electricity, and the vibrations of the piezoelectric actuators are transmitted to the first and second stages 411 and 412, thereby moving them. With this configuration, the amount of movement and the speed of movement of the first and second stages 411 and 412 can be controlled finely and with high precision, and the switching of the direction of movement is also quick. In addition, the moving stage 4 can be made smaller and lighter. As a result, the position correction of the print head 5 can be performed with greater precision.

[0021] However, the configuration of the moving stage 4 is not particularly limited. For example, the first and second stage drive units 421 and 422 may be configured to use a drive source other than a piezoelectric actuator, such as a motor that rotates when energized. Furthermore, the moving stage 4 may also have a third stage that moves linearly in a direction perpendicular to the first direction A and the second direction B, or a fourth stage that rotates around an axis perpendicular to the first direction A and the second direction B. The moving stage 4 may also be omitted. In this case, the print head 5 can be attached to the arm 326. The moving stage 4 may also be configured to move in only one direction.

[0022] ≪Print Head 5≫ As shown in Figure 2, the print head 5 is supported by the second stage 412. The print head 5 is not particularly limited, but in this embodiment it is a piezo-driven inkjet head. As shown in Figures 3 and 4, such a print head 5 has a configuration in which a nozzle plate 51, a pressure chamber forming substrate 52, a diaphragm 53, and a sealing part 54 are stacked, and has a reservoir 561 which is a common ink chamber, a plurality of ink chambers 562 branching from the reservoir 561, and a plurality of nozzles 563 formed in each ink chamber 562. The plurality of ink chambers 562 are arranged in a line along a direction perpendicular to the printing trajectory Q. In other words, the printing trajectory Q is the direction perpendicular to the direction in which the plurality of ink chambers 562 are arranged. A piezoelectric vibrating element 564 is also arranged on the diaphragm 53 which forms the ceiling of each ink chamber 562. For the sake of explanation, in the following, as shown in Figure 2, the surface in which the plurality of nozzles 563 are arranged will also be called the "nozzle surface Fn".

[0023] In a print head 5 with this configuration, ink I is supplied from the reservoir 561 to each ink chamber 562. Then, at a predetermined timing, an ink ejection voltage is applied to a piezoelectric vibrating element 564 for each ink chamber 562, causing the piezoelectric vibrating element 564 to vibrate and eject ink I from the nozzle 563. As a result, by moving the print head 5 along the print trajectory Q and ejecting ink I from each nozzle 563 at predetermined timings, the ink 1 is made to land on the target object W, thereby printing a predetermined print pattern on the target object W.

[0024] However, the configuration of the print head 5 is not particularly limited. For example, a configuration capable of multi-color printing may be made by arranging multiple print heads 5 in a row along the print trajectory Q. Specifically, for example, full-color printing may be made by arranging a print head 5 that ejects black ink I, a print head 5 that ejects cyan ink I, a print head 5 that ejects magenta ink I, and a print head 5 that ejects yellow ink I along the print trajectory Q. Furthermore, the print head 5 is not limited to the piezo-driven inkjet head described above. For example, it may be an inkjet head of the thermal type that utilizes the film boiling phenomenon of ink I, a bubble ejection type that generates bubbles in the ink I by applying heat and ejects the ink I, or an electrostatic actuator type that ejects ink I by displacing and vibrating a diaphragm with electrostatic force.

[0025] ≪Inertial Sensor 6≫ As shown in Figures 1 and 2, the inertial sensor 6 is positioned on the print head 5 and detects vibrations of the print head 5. The term "vibration" here refers to unwanted displacements other than those along the print trajectory Q of the print head 5. The inertial sensor 6 is not particularly limited as long as it can detect vibrations; for example, a three-axis angular velocity sensor that detects acceleration in three mutually orthogonal axes can be used. The position of the inertial sensor 6 is also not particularly limited as long as it can detect vibrations of the print head 5; for example, it may be positioned on the second stage 412.

[0026] Barrier Wall 7 The barrier wall 7 blocks the airflow C in front of the nozzle 563 and functions as a windbreak to prevent the ink I ejected from the print head 5 and flying toward the target object W from being affected by the airflow C. As shown in Figure 2, such a barrier wall 7 is fixed to the side of the print head 5, and its relative position to the print head 5 is kept constant. However, the arrangement of the barrier wall 7 is not particularly limited; for example, it may be placed on the second stage 412 together with the print head 5, thereby keeping its relative position to the print head 5 constant. In the robot system 1, when printing is completed, a cap may be attached to the print head 5 to prevent the ink I from drying out and to prevent contamination of the nozzle 563. In such cases, if the barrier wall 7 is fixed to the print head 5, it may be difficult to attach the cap to the print head 5. In contrast, if the barrier wall 7 is fixed to the second stage 412, there is the advantage that it is less likely to be hindered in attaching the cap to the print head 5.

[0027] As shown in Figure 2, the barrier wall 7 is arranged in parallel with the print head 5, and further, as shown in Figure 5, in a plan view from a direction perpendicular to the ink I ejection direction, it is provided protruding from each nozzle 563 of the print head 5, that is, from the nozzle surface Fn in the direction of ink I ejection. Therefore, the tip of the barrier wall 7 is located on the object W side of the nozzle surface Fn. Also, in a plan view from the direction of ink I ejection, the barrier wall 7 is located on both sides of each nozzle 563 in the direction along the print trajectory Q. For the sake of explanation, in the following, the barrier wall located on one side will be referred to as the first barrier wall 71, and the barrier wall 7 located on the other side will be referred to as the second barrier wall 72.

[0028] However, the configuration of the barrier wall 7 is not particularly limited. For example, as shown in Figure 6, the second barrier wall 72 may be omitted, or as shown in Figure 7, it may be a frame-shaped structure surrounding all four sides of each nozzle 563. In particular, the frame-shaped structure as shown in Figure 7 further improves its function as a windbreak. However, with a frame-shaped configuration as shown in Figure 7, the barrier wall 7 is more likely to come into contact with the object W during printing compared to the configuration of this embodiment, and the constraints on the printing trajectory Q increase. Therefore, considering the overall advantages and disadvantages, the configuration of this embodiment is the most preferred.

[0029] ≪Control device 9≫ As shown in Figure 1, the control device 9 is electrically connected to the robot 2 and controls the movement of the robot 2. Specifically, the control device 9 independently or in conjunction with the movement of the robot body 3, the mobile stage 4, the print head 5, and the inertial sensor 6. Such a control device 9 is, for example, composed of a computer and has a processor (CPU) that processes information, a memory that is communicatively connected to the processor, and an external interface for connecting to external devices. Various programs that can be executed by the processor are stored in the memory, and the processor can read and execute the programs stored in the memory. Note that there may be multiple control devices 9, and the robot body 3, the mobile stage 4, the print head 5, and the inertial sensor 6 may each be controlled by a different control device 9.

[0030] The configuration of the robot system 1 has been described above. Next, the printing method using the robot system 1 will be described. As shown in Figure 5, the printing method using the robot system 1 involves maintaining a position in which the barrier wall 7 is located upstream of the airflow C relative to each nozzle 563, while the robot arm 32 moves the print head 5 along the printing trajectory Q relative to the object W, and ejecting ink I from each nozzle 563 toward the object W at predetermined timings to print on the object W.

[0031] In the illustrated example, since the airflow C follows a downward vertical direction, the first barrier wall 71 is positioned vertically upward (windward) relative to each nozzle 563. As a result, the airflow C is blocked by the first barrier wall 71 in front of each nozzle 563, effectively suppressing the collision of the airflow C with the ink I being ejected from the nozzle 563 and flying towards the target object W. Therefore, it becomes less likely that some of the ink I will scatter during flight, that the organic solvent contained in the ink I will evaporate, or that the point of impact of the ink I on the target object W will shift. Consequently, a decrease in print quality can be effectively suppressed, enabling high-quality printing.

[0032] In particular, in this embodiment, the second barrier wall 72 is positioned vertically below each nozzle 563, that is, behind the printing trajectory Q. This allows, for example, as shown in Figure 8, droplets of ink I that scatter into the atmosphere due to the impact of impact to adhere to the inner surface 721 of the second barrier wall 72, which follows behind the print head 5, and be quickly collected. Therefore, it is possible to effectively suppress nozzle 563 ejection failures caused by droplets adhering to the nozzle surface Fn, and the deterioration of print quality caused by droplets re-adhering to the target object W. Consequently, higher quality printing becomes possible. Furthermore, since the nozzle surface Fn is less likely to get dirty, the frequency of cleaning the nozzles 563 can be reduced, thereby reducing the burden and cost of maintenance.

[0033] Furthermore, the inner surface 721 of the second barrier wall 72 may be treated to facilitate the adhesion of droplets. The treatment is not particularly limited, but examples include forming minute irregularities on the inner surface 721 to suppress the detachment of attached droplets, or placing an adsorption sheet capable of adsorbing droplets on the inner surface 721.

[0034] Furthermore, the presence of the second barrier wall 71 provides the following benefits. For example, as shown in Figure 5, if the printing trajectory Q is a trajectory that circles the object W, and the print head 5 is moved vertically upward in the first half and vertically downward in the second half, the airflow C can be blocked by the first barrier wall 71 in the first half and by the second barrier wall 71 in the second half. In this way, the airflow C can always be blocked during printing by either the first or second barrier wall 71 or 72, enabling higher quality printing. In addition, the degree of freedom of the printing trajectory Q is increased, and the working time can be shortened.

[0035] During printing, it is preferable to keep the first and second barrier walls 71 and 72 from contacting the object W while keeping their tips as close to the object W as possible. If the first and second barrier walls 71 and 72 come into contact with the object W, the friction between them may cause the print head 5 and the object W to vibrate, potentially degrading the print quality. In contrast, by keeping the first and second barrier walls 71 and 72 from contacting the object W, such problems do not occur, and high-quality printing becomes possible.

[0036] In particular, by keeping the second barrier wall 72 in non-contact with the object W, contact of the second barrier wall 72 with the printed pattern that is not yet completely dry immediately after printing is suppressed, thereby effectively suppressing printing smudges, defects, etc. Furthermore, by bringing the tips of the first and second barrier walls 71 and 72 as close as possible to the object W, the airflow C can be effectively blocked by the first barrier wall 71, enabling higher quality printing. The distance between the tips of the first and second barrier walls 71 and 72 and the object W is not particularly limited, but is preferably 2.0 mm or less, more preferably 1.0 mm or less, and even more preferably 0.5 mm or less.

[0037] Furthermore, during printing, the robot system 1 detects vibrations of the print head 5 based on the output of the inertial sensor 6 and controls the drive of the moving stage 4 so that the detected vibrations are canceled out. Specifically, the drive of the moving stage 4 is controlled so that vibrations with the opposite phase to the detected vibrations are applied to the print head 5. This suppresses vibrations of the print head 5 during printing, enabling higher quality printing.

[0038] The above describes the printing method, but the printing method is not limited to this. For example, during the printing process, at least one of the first and second barrier walls 71 and 72 may be brought into contact with the object W. Specifically, for example, only the first barrier wall 71 may be brought into contact with the object W, while the second barrier wall 71 is not in contact with the object W. This allows the first barrier wall 71 to more effectively block the airflow C, enabling higher quality printing. The second barrier wall 71 may also be brought into contact with the object W. This increases the rate at which the second barrier wall 72 collects droplets, enabling higher quality printing. In this case, for example, by using a fast-drying ink I or slowing down the movement speed of the print head 5, the second barrier wall 72 can be brought into contact with the object W only after the printed pattern has completely dried. This effectively suppresses blurring, defects, etc., of the printed pattern. Alternatively, for example, the print head 5 may be moved along the printing trajectory Q by driving only the moving stage 4 while the robot arm 32 is stopped.

[0039] The control method and robot system 1 have been described above. The control method for this robot system 1 uses a robot 2 having a robot arm 32, a print head 5 positioned on the robot arm 32 and ejecting ink I from a nozzle 563, and a barrier wall 7 positioned parallel to the print head 5 and positioned to protrude further in the direction of ink I ejection than the nozzle 563 when viewed from a plane perpendicular to the direction of ink I ejection. In an environment where airflow C is present, the robot 2 maintains a position where the barrier wall 7 is located upstream of the airflow C relative to the nozzle 563, and moves the print head 5 and the target object W relatively along the printing trajectory Q, ejecting ink I from the nozzle 563 toward the target object W at a predetermined timing, thereby printing on the target object W. With this configuration, the airflow C is blocked by the barrier wall 7 in front of the nozzle 563, effectively suppressing the collision of the airflow C with the ink I in flight. As a result, scattering of ink I during flight, evaporation of organic solvents contained in the ink I, and deviations in the landing position of the ink I on the target object W are less likely to occur. Therefore, the deterioration of print quality can be effectively suppressed, enabling high-quality printing.

[0040] Furthermore, as mentioned above, the blocking walls 7 are arranged in pairs on both sides of the nozzle 563 in a plan view from the direction of ink I ejection. During printing, one blocking wall 7 is positioned upstream of the airflow C relative to the nozzle 563, and the other blocking wall 7 is positioned downstream of the airflow C relative to the nozzle 563. With this configuration, for example, as shown in Figure 5 above, even if the orientation of the print head 5 changes with respect to the direction of the airflow C during printing, the airflow C can be blocked in front of the nozzle 563.

[0041] Furthermore, as mentioned above, during printing, the pair of barrier walls 7 maintain an alignment along the printing track Q, and droplets of ink I adhere to the barrier walls 7 located behind the printing track Q. With this configuration, it is possible to effectively suppress nozzle ejection failures caused by droplets adhering to the nozzle surface Fn, and the deterioration of print quality caused by droplets re-adhering to the object W. Therefore, higher quality printing becomes possible.

[0042] As mentioned above, the robot system 1 is positioned between the robot arm 32 and the print head 5 and has a moving stage 4 that moves the print head 5 relative to the robot arm 32. With this configuration, during printing, vibrations of the print head 5 are detected based on the output of the inertial sensor 6, and the drive of the moving stage 4 is controlled so that the detected vibrations are canceled, thereby suppressing vibrations of the print head 5 during printing and enabling higher quality printing. Also, for example, the print head 5 can be moved by driving only the moving stage 4 while the drive of the robot arm 32 is stopped. Therefore, vibrations of the print head 5 during printing are suppressed, enabling higher quality printing.

[0043] As mentioned above, the moving stage 4 includes a base 40 supported by the robot arm 32, a movable stage 41 that is movable relative to the base 40 and on which the print head 5 is positioned, and a piezoelectric drive unit 42 that moves the movable stage 41 relative to the base 40. With this configuration, since the piezoelectric drive unit 42 is used as the drive source, the amount of movement and the speed of movement of the movable stage 41 can be controlled finely and with high precision, and the direction of movement can be switched quickly. In addition, the moving stage 4 can be made smaller and lighter. As a result, the position correction of the print head 5 can be performed with greater precision.

[0044] As mentioned above, the robot system 1 includes a robot arm 32, a print head 5 positioned on the robot arm 32 that ejects ink I from a nozzle 563, and a barrier wall 7 positioned parallel to the print head 5 and, in a plan view from a direction perpendicular to the ink I ejection direction, positioned to protrude further in the ink I ejection direction than the nozzle 563. In an environment where airflow C is present, the barrier wall 7 is positioned upstream of the airflow C relative to the nozzle 563, and the print head 5 and the target object W are moved relative to each other along the printing trajectory Q, while ink I is ejected from the nozzle 563 toward the target object W at a predetermined timing, thereby printing onto the target object W. With this configuration, the airflow C is blocked by the barrier wall 7 in front of the nozzle 563, effectively suppressing the collision of the airflow C with the ink I in flight. As a result, scattering of ink I during flight, evaporation of organic solvents contained in the ink I, and deviations in the landing position of the ink I on the target object W are less likely to occur. Consequently, a decrease in print quality can be effectively suppressed, enabling high-quality printing.

[0045] <Second Embodiment> Figure 9 shows a print head in the robot system according to the second embodiment. Figures 10 and 11 show modified examples of the barrier wall, respectively.

[0046] This embodiment is the same as the first embodiment described above, except that the configuration of robot 2 is different. In the following description, this embodiment will focus on the differences from the first embodiment described above, and similar matters will not be explained. Also, in the figures of this embodiment, the same reference numerals are used for components that are the same as in the previously described embodiment.

[0047] In the robot system 1 of this embodiment, UV ink that hardens when exposed to ultraviolet light is used as the ink I. Therefore, as shown in Figure 10, the robot 2 further has an ultraviolet irradiation unit 8 that irradiates the ink I attached to the object W with ultraviolet light. The ultraviolet irradiation unit 8 is fixed to the side of the print head 5, and its relative position to the print head 5 is kept constant. However, the arrangement of the ultraviolet irradiation unit 8 is not particularly limited, and for example, it may be arranged on the second stage 412 together with the print head 5 so that its relative position to the print head 5 is kept constant. During printing, such an ultraviolet irradiation unit 8 is located behind the print trajectory Q relative to the print head 5. With such an arrangement, the ink I attached to the object W can be quickly irradiated with ultraviolet light by the ultraviolet irradiation unit 8. Therefore, high-quality printing is possible.

[0048] Furthermore, during printing, the ultraviolet irradiation unit 8 is positioned behind the printing path Q, beyond the second barrier wall 72 which is located behind the printing path Q relative to the print head 5. With this configuration, the adhesion of droplets to the ultraviolet irradiation unit 8 can be suppressed, and a sufficient amount of ultraviolet UV light can be more reliably irradiated onto the ink I. In addition, the second barrier wall 72 prevents the light from the ultraviolet irradiation unit 8 from hitting the nozzle 563. Therefore, the hardening of the ink on the nozzle 563 surface can be suppressed.

[0049] In this embodiment, as described above, the ink I is a UV ink that hardens upon irradiation with ultraviolet (UV) light. Accordingly, the robot system 1 has an ultraviolet irradiation unit 8 that irradiates the ink I attached to the object W with ultraviolet (UV) light. During printing, the ultraviolet irradiation unit 8 is located behind the printing track Q, beyond the second barrier wall 72, which is a barrier wall 7 located behind the printing track Q. With this configuration, the adhesion of droplets to the ultraviolet irradiation unit 8 can be suppressed, and a sufficient amount of ultraviolet (UV) light can be more reliably irradiated onto the ink I.

[0050] The second embodiment described above can also achieve the same effects as the first embodiment described above.

[0051] However, the configuration of the robot system 1 is not particularly limited. For example, as shown in Figure 10, the second barrier wall 72 may be located behind the printing track Q relative to the ultraviolet irradiation unit 8 during printing. Also, as shown in Figure 11, the barrier wall 7 may further have a third barrier wall 73 located behind the printing track Q relative to the ultraviolet irradiation unit 8.

[0052] <Third Embodiment> Figure 12 shows a print head of the robot system according to the third embodiment.

[0053] This embodiment is the same as the first embodiment described above, except that the configuration of robot 2 is different. In the following description, this embodiment will focus on the differences from the first embodiment described above, and similar matters will not be explained. Also, in the figures of this embodiment, the same reference numerals are used for components that are the same as in the previously described embodiment.

[0054] As shown in Figure 12, in the robot system 1 of this embodiment, the barrier wall 7 is composed of an air curtain that forms a wall of air G by injecting air G, which is a gas. Specifically, ejection devices 74 that eject air G are arranged on both sides in the direction along the printing trajectory Q of the print head 5. By forcefully ejecting air G from each ejection device 74 toward the object W, the first and second barrier walls 71 and 72, which are composed of walls of air G, are formed. With this configuration, the degree of freedom of the printing trajectory Q is increased compared to the case in the first embodiment described above, where the first and second barrier walls 71 and 72 are composed of tangible objects. In addition, dust and other debris adhering to the surface of the object W can be removed by the first barrier wall 71 located in front of the printing trajectory Q just before printing. In addition, the drying of the printed pattern on the object W can be promoted by the second barrier wall 72 located behind the printing trajectory Q. Therefore, the print quality can be improved.

[0055] In particular, in this embodiment, the first barrier wall 71 is inclined toward the front of the printing track Q, and the second barrier wall 72 is inclined toward the rear of the printing track Q. This effectively suppresses the air G that collides with the object W from bouncing back towards the ink I in flight.

[0056] The third embodiment described above can also achieve the same effects as the first embodiment described above.

[0057] However, the configuration of the robot system 1 is not particularly limited, and for example, either the first or second barrier wall 71, 72 may be a wall made of a tangible object as described in the first embodiment above.

[0058] The third embodiment described above can also achieve the same effects as the first embodiment described above.

[0059] The control method and robot system of the present invention have been described above with reference to the illustrated embodiments. However, the present invention is not limited thereto, and the configuration and processes of each part can be replaced with any configuration or process having a similar function. Furthermore, other arbitrary configurations and processes may be added to the present invention. In addition, each embodiment may be combined as appropriate. [Explanation of Symbols]

[0060] 1...Robot system, 2...Robot, 3...Robot body, 31...Base, 32...Robot arm, 321...Arm, 322...Arm, 323...Arm, 324...Arm, 325...Arm, 326...Arm, 4...Moving stage, 40...Base, 41...Movable stage, 411...First stage, 412...Second stage, 42...Piezoelectric drive unit, 421...First stage drive unit, 422...Second stage drive unit, 5...Print head, 51...Nozzle plate, 52...Pressure chamber forming substrate, 53...Vibrator, 54... Sealing section, 561…Reservoir, 562…Ink chamber, 563…Nozzle, 564…Piezoelectric vibration element, 6…Inertial sensor, 7…Blocking wall, 71…First barrier wall, 72…Second barrier wall, 721…Inner surface, 73…Third barrier wall, 74…Ejection device, 8…Ultraviolet irradiation section, 9…Control device, A…First direction, B…Second direction, C…Airflow, Fn…Nozzle surface, G…Air, I…Ink, J1…Joint, J2…Joint, J3…Joint, J4…Joint, J5…Joint, J6…Joint, Q…Printing trajectory, R…Printing chamber, UV…Ultraviolet light, W…Target object

Claims

1. A robot is used that includes a robotic arm, a print head positioned on the robotic arm and ejecting ink from a nozzle, and a barrier wall positioned parallel to the print head and, in a plan view from a direction perpendicular to the ink ejection direction, protruding further in the ejection direction than the nozzle. A method for controlling a robot system, characterized in that, in an environment where airflow is present, printing is performed on an object by maintaining a position in which the barrier wall is located upstream of the airflow relative to the nozzle, while moving the print head and the object relative to each other along a printing trajectory, and ejecting the ink from the nozzle toward the object at a predetermined timing.

2. The aforementioned blocking walls are arranged in pairs on both sides of the nozzle in a plan view from the discharge direction. A method for controlling a robot system according to claim 1, wherein during printing, one of the barrier walls is positioned upstream of the airflow relative to the nozzle, and the other barrier wall is positioned downstream of the airflow relative to the nozzle.

3. A method for controlling a robot system according to claim 2, wherein during printing, the pair of barrier walls maintain a position aligned along the printing track, and ink droplets are deposited on the barrier wall located behind the printing track.

4. The aforementioned ink is a UV ink that hardens upon irradiation with ultraviolet light. The object has an ultraviolet irradiation unit that irradiates ultraviolet light onto the ink adhering to the object, The method for controlling a robot system according to claim 3, wherein during the printing, the ultraviolet irradiation unit is located behind the printing track, beyond the barrier wall located behind the printing track.

5. A method for controlling a robot system according to claim 1, comprising a moving stage positioned between the robot arm and the print head, for moving the print head relative to the robot arm.

6. The method for controlling a robot system according to claim 5, wherein the moving stage comprises a base supported by the robot arm, a movable stage movable relative to the base on which the print head is located, and a piezoelectric drive unit for moving the movable stage relative to the base.

7. The robot has a base positioned between the robot arm and the print head and supported by the robot arm, a movable stage that is movable relative to the base and supports the print head, and a piezoelectric drive unit that moves the movable stage relative to the base, and a moving stage that moves the print head relative to the robot arm by driving the movable stage, The aforementioned blocking walls are arranged in pairs on both sides of the nozzle in a plan view from the discharge direction. A method for controlling a robot system according to claim 1, wherein during printing, a pair of the barrier walls are aligned along the printing track, and one of the barrier walls is positioned upstream of the airflow relative to the nozzle, and the other barrier wall is positioned downstream of the airflow relative to the nozzle, and ink droplets are deposited on the barrier wall located behind the printing track.

8. A robotic arm and The robot arm is equipped with a print head that ejects ink from a nozzle, The print head is arranged in parallel with the barrier wall, and in a plan view from a direction perpendicular to the ink ejection direction, the barrier wall is positioned to protrude further in the ejection direction than the nozzle, A robotic system characterized by performing printing on an object by, in an environment where airflow is present, maintaining a position in which the barrier wall is located upstream of the airflow relative to the nozzle, while relatively moving the print head and the object along a printing trajectory, and ejecting the ink from the nozzle toward the object at a predetermined timing.

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