JP2006142621A - Ink jet application apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet application apparatus which can always stably carry out application of liquid droplets. <P>SOLUTION: The ink jet application apparatus 1 is equipped with cleaning mechanisms 70 and 80 which clean a nozzle face 48 of an ink jet head 42 that has the nozzle face 48 where nozzle jet openings 50 as openings for jetting the liquid droplets are formed, and a control part 10 which carries out a cleaning process for the nozzle face 48 by the cleaning mechanisms 70 and 80 by making the cleaning process follow an application process of the liquid droplets to an application object 30 of the liquid droplets. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet coating apparatus that sprays ink droplets to coat a coating target.

  In personal computers and the like, a liquid crystal display is used as the display device. In the manufacturing process of this liquid crystal display, R (red), G (green), R (red), G (green) on a transparent substrate using a so-called inkjet coating device (see Patent Document 1) designed to eject fine droplets from nozzles. By applying B (blue) inks in sequence, a color filter in which dots of these colors are arranged in sequence is created.

  A light shielding region for shielding light from the backlight is provided around the color filter. In such a light shielding region, for example, black ink is applied to the entire surface of the region to shield unnecessary light from the backlight around the display region.

An ink jet coating apparatus is used when dots of each color are applied to the color filter or when black ink is applied to the light shielding region of the color filter. In an inkjet coating apparatus, ink is ejected at an ink application position while relatively moving an inkjet head provided with a plurality of nozzles for ejecting ink and a substrate to be coated.
JP 2004-111074 A

  In the ink jet coating apparatus, when the ink in the nozzles of the ink jet head is dried, or in order to prevent the ink from being dried, maintenance work such as manually cleaning the ink ejection ports of the nozzles is required.

  Such manual maintenance work varies depending on the operator, and it is difficult to realize stable ink application.

  The present invention has been made to solve such a technical problem, and an object of the present invention is to provide an ink jet coating apparatus capable of always stably applying droplets.

  A first feature according to an embodiment of the present invention is that a cleaning mechanism for cleaning a nozzle surface of an inkjet head having a nozzle surface provided with a nozzle injection port which is an opening for ejecting droplets in an inkjet coating apparatus. And a control unit that executes the cleaning process of the nozzle surface by the cleaning mechanism depending on the droplet application process for the droplet application target.

  According to the present invention, it is possible to always stably apply droplets in an inkjet coating apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
[Overall configuration of inkjet coating apparatus]
As shown in FIG. 1, the ink jet coating apparatus 1 according to the first embodiment of the present invention includes an ink application unit 3 that applies ink to a substrate 30 using an ink jet head 42 that ejects ink droplets from nozzles. A maintenance unit 4 that prevents the nozzles of the inkjet head 42 from being dried, and that maintains the nozzles in a state where the ink droplets are constantly ejected stably, and an application position adjustment unit 5 that adjusts the ejection positions of the ink droplets It has.

  In the ink application unit 3, a Y-axis direction guide plate 20 is fixed to the upper surface of the gantry 2, and a plurality of guide grooves 21 extend in the Y direction on the upper surface of the Y-direction guide plate 20. A guide protrusion (not shown) provided on the lower surface of the Y-direction moving table 22 is engaged with the guide groove 21, whereby the Y-direction moving table 22 is guided by the guide groove 21 to the Y direction. It is supported to move freely. The Y direction moving table 22 is moved in the Y direction along the guide groove 21 by a drive mechanism using a Y direction moving motor (not shown).

  A plurality of guide grooves (not shown) extend in the X direction on the upper surface of the Y-direction moving table 22. A guide protrusion (not shown) provided on the lower surface of the X-direction moving table 23 is engaged with the guide groove, whereby the X-direction moving table 23 is guided by the guide groove to be in the X direction. It is supported to move freely. The X-direction moving table 23 is moved in the X direction along the guide groove by a driving mechanism using an X-direction moving motor (not shown).

  A substrate holding table 26 is fixed to the upper surface of the X-direction moving table 23, and a substrate 30 that is a target of ink application is held on the upper surface of the substrate holding table 26 by a gripping mechanism (not shown). It is designed to be fixed. Note that the method for fixing the substrate 30 may be, for example, a method in which the substrate 30 is sucked by a suction mechanism instead of gripping by the gripping mechanism.

  The amount of movement of the substrate holding table 26 in the X direction can be detected based on a pulse output signal of an X direction encoder (not shown), and the amount of movement of the substrate holding table 26 in the Y direction is Y Detection can be performed based on a pulsed output signal of a direction encoder (not shown).

  In the ink application unit 3, an inkjet head unit 40 is supported on the upper surface of the gantry 2 so as to be movable in the X direction, the Y direction, and the Z direction which is the vertical direction.

  That is, in the ink application unit 3, a pair of columns 33 a and 33 b are erected on the upper surface of the gantry 2 at positions where the Y-axis direction slide plate 20 is sandwiched. A plate 35 is laid horizontally.

  A guide groove 36 extends in the X direction on the front surface of the X direction guide plate 35, and a protrusion of a base plate 41 that vertically mounts a plurality of inkjet head units 40 is engaged with the guide groove 36. ing. As a result, the base plate 41 is supported by the guide groove 36 so as to be movable in the X-axis direction. The base plate 41 is moved in the X-axis direction along the guide groove 36 by a drive mechanism using a head unit moving motor (not shown).

  In the ink applicator 3, the controller 10 that controls the operation of the ink jet applicator 1 moves the Y-direction moving table 22 in the Y-axis direction, the X-direction moving table 23 in the X-axis direction, and the base plate. 41 is controlled in the X-axis direction, whereby the relative position between the substrate 30 held by the substrate holding table 26 and the inkjet head unit 40 suspended from the base plate 41 can be changed variously. .

  A plurality of inkjet head units 40 are suspended from the base plate 41. In the inkjet head unit 40, ink is ejected downward by an inkjet head 42 provided at the lower end thereof. The plurality of inkjet head units 40 have the same configuration.

  As shown in FIG. 2, in the inkjet head unit 40, a Z-direction moving mechanism 44 that is supported by the base plate 41 and supports the moving portion 44 a so as to be movable in the Z direction (vertical direction), and the Z-direction moving mechanism 44. The Y-direction moving mechanism 45 is supported by the moving portion 44a and movably supports the moving portion 45a in the Y direction, and is supported by the moving portion 45a of the Y-direction moving mechanism 45, and rotates the rotating portion 46a around the Z direction. A θ-direction rotating mechanism 46 that is rotatably supported in the θ-direction, and an inkjet head 42 that is suspended by a rotating portion 46 a of the θ-direction rotating mechanism 46. The position can be adjusted in the Z direction with respect to the substrate 30, and the position of the inkjet head 42 can be adjusted with respect to the substrate 30 by the Y direction moving mechanism 45. It can be adjusted in the direction. Further, the direction of the inkjet head 42 can be rotated in the θ direction with respect to the substrate 30 by the θ direction rotation mechanism 46. Each of the Y-direction moving mechanism 45 and the Z-direction moving mechanism 44 is provided with a head adjustment motor (not shown), which can move the inkjet head 42 in the Y direction and Z direction by driving the motor. . The θ-direction rotating mechanism 46 is provided with a θ-direction rotating motor (not shown), which allows the inkjet head 42 to be rotated in the θ direction by driving the motor. The rotation amount of the inkjet head 42 in the θ direction can be detected based on a pulse-like output signal of a θ direction encoder (not shown).

  Thus, in the inkjet head unit 40, the position of the inkjet head 42 relative to the substrate holding table 26 can be variously adjusted.

  As shown in FIG. 3, in the inkjet head 42 provided at the lower end of the inkjet head unit 40, a plurality of nozzles respectively direct the nozzle injection ports 50 downward on the nozzle surface 48 directed downward. Are formed in series at regular intervals.

  An ink tank that communicates with each nozzle is provided inside the ink jet head 42, and a diaphragm and a piezoelectric element are provided for each nozzle on the upper surface of the ink tank. The piezoelectric element is driven by an ejection control signal from the control unit 10 to change the pressure in the ink tank and eject the ink in the ink tank from the nozzle. In the inkjet head unit 40, the ink is applied to the upper surface of the substrate 30 held by the substrate holding table 26 below the inkjet head 42 by ejecting ink downward from the nozzle ejection port in this way.

[Configuration of control unit]
Next, the control unit 10 that controls the ink application process will be described. As shown in FIG. 4, the control unit 10 is provided with an ink ejection control circuit 11 that controls movement of the substrate holding table 26 and the inkjet head 42 and controls ejection of ink in the inkjet head 42. The ink ejection control circuit 11 is connected to a drive circuit 12 for driving an X direction movement motor, a Y direction movement motor, and a θ direction rotation motor.

  The control unit 10 is provided with a Y-direction counter 13 and an X-direction counter 14 for counting the pulse outputs of the Y-direction encoder and the X-direction encoder, respectively. These counters are supplied from the X-direction encoder and the Y-direction encoder. When the count result of the number of output pulses reaches a preset count value, a count result signal indicating that the count value has been reached is sent to the ink ejection control circuit 11. Further, the control unit 10 is provided with a θ direction counter 15 that counts the pulse output of the θ direction encoder, and this counter is a count value in which the count result of the number of pulses output from the θ direction encoder is set in advance. When the value reaches the count value, a count result signal indicating that the count value has been reached is sent to the ink ejection control circuit 11.

  As a result, the ink ejection control circuit 11 determines whether or not the substrate holding table 26 has moved by a preset amount of movement from the Y-direction counter 13 and the X-direction counter 14 when a drive signal is sent to each motor. Determination can be made based on the output count result signal, and determination can be made based on the count result signal output from the θ-direction counter 15 whether the inkjet head 42 has been rotated by a preset rotation amount. Can do.

  A memory device 17 is connected to the ink ejection control circuit 11, and the memory device 17 includes data on voltage waveform applied to the piezoelectric element of each nozzle of the inkjet head 42 and parameters relating to ink ejection conditions for each ink dot. Is stored in advance. The memory device 17 stores these voltage waveform data and parameters in association with data representing each ink dot position. As this memory device 17, for example, a rewritable EPROM (Erasable Programmable ROM) is used.

  By changing the voltage waveform applied to the piezoelectric element of the nozzle, it is possible to control the amount of ink droplets ejected from the nozzles of the inkjet head 42, so the optimum droplet amount according to each ink dot position Is stored in the memory device 17.

  The ink ejection control circuit 11 is connected to a nozzle drive circuit 18 for applying a voltage to the piezoelectric element of each nozzle of the inkjet head 42, and the ink ejection control circuit 11 is positioned relative to the substrate 30. When the ink reaches the ink application position, voltage waveform data corresponding to the ink application position (ink dot position) stored in the memory device 17 is read out and sent to the nozzle drive circuit 18. The nozzle drive circuit 18 generates a voltage based on the voltage waveform data and applies it to the nozzle. As a result, ink can be ejected from the nozzles of the inkjet head 42 that has reached the ink application position of the substrate 30.

[Configuration of application position adjustment unit]
As shown in FIG. 1, the application position adjusting unit 5 includes a temporary application stage that trially strikes ink droplets and an imaging unit 56 that images the ink droplets applied to the temporary application stage 55. The temporary application stage 55 is provided on the X-axis direction moving table 23, and the paper 54 disposed on the temporary application stage 55 is moved by relatively moving the inkjet head 42 and the X-axis direction moving table 23. On the other hand, ink droplets are applied by the inkjet head 42.

  The imaging unit 56 is fixed to one of the inkjet head units 40, and can be moved together with the inkjet head unit 40 by moving the inkjet head unit 40 by the X-direction moving mechanism and the Y-direction moving mechanism 45. it can.

  In the control unit 10 (FIG. 4), reference position information for applying ink droplets to the temporary application stage 55 is stored in the memory device 17, and the control unit 10 moves the substrate holding table 26 and the inkjet head 42 relative to each other. By moving the ink jet head 42 to this reference position and ejecting ink droplets, the ink droplets ejected at the reference position are applied to the paper 54 placed on the temporary application stage 55. .

  The control unit 10 moves the imaging unit 56 to image the ink droplets applied to the paper 54 of the temporary application stage 55. The ink ejection control circuit 11 of the control unit 10 detects the position where the ink droplet is applied based on the image captured by the imaging unit 56, and based on the detection result, the ink jet head 42 in the θ direction. Adjust the angle.

  That is, as shown in FIG. 5A, when the normal head angle for applying ink droplets to the normal application position is θ2 with respect to the reference direction θ0, the actual head angle is θ1 (= If θ2 + Δθ), as shown in FIG. 5B, the actual application position P1 is shifted from the normal application position P2.

The control unit 10 compares the application width d1 of the ink droplet applied by each nozzle 50 of the inkjet head 42 with the normal application width d2. In this case, from the relationship of cos θ1 / cos θ2 = d1 / d2, the difference Δθ between the actual head angle θ1 and the normal head angle θ2 is Δθ = θ1-cos ⁻¹ ((d2 / d1) · cos θ1). The controller 10 calculates the angle Δθ and rotates the inkjet head 42 in the θ direction by the angle Δθ, so that the ink droplets can be applied to the regular position.

  In addition, although FIG. 5 describes the case where the head angle is adjusted, the application position in the X direction and the Y direction can also be adjusted. In this case, the control unit 10 images the application position of the ink droplet applied to the temporary application stage 55 by the imaging unit 56, and based on this imaging result, calculates the difference between the actual application position and the regular application position. The inkjet head 42 is moved in the X and Y directions by this difference. Thereby, the application position adjustment in the X direction and the Y direction can be performed.

  In the inkjet coating apparatus 1, the ejection amount of ink droplets from each nozzle 50 is adjusted along with the adjustment of the coating position. That is, the control unit 10 images the landing diameter of the ink droplet applied to the temporary application stage 55 by the imaging unit 56. The control unit 10 can change the landing diameter by measuring the landing diameter based on the imaging result and changing the voltage value applied to the piezoelectric element of each nozzle 50 based on the measurement result.

[Configuration of Maintenance Department]
As shown in FIG. 1, the maintenance unit 4 disposed on the upper surface of the gantry 2 includes an immersion unit 60 that immerses the nozzle surface 48 of the inkjet head 42 in the droplet solvent, and sprays the droplet solvent onto the nozzle surface 48. There are provided a solvent injection unit 70 for performing suction and a suction unit 80 for sucking the nozzle surface 48.

  As shown in FIG. 6, the inkjet head 42 includes an X-direction moving mechanism using an X-direction guide plate 35 (FIG. 1) and a head unit moving motor, a Y-direction moving mechanism 45 (FIG. 2), and a Z-direction moving mechanism 44. (FIG. 2), the inkjet head 42 can be positioned by moving the upper part of the maintenance unit 4 in the X direction, the Y direction, and the Z direction.

  As shown in FIG. 7A, the immersion unit 60 includes a solvent tank 61 and a solvent storage tank 62 that supplies the solvent 64 to the solvent tank 61. The solvent storage tank 62 stores the solvent 64 therein, and applies a positive pressure from the outside, thereby supplying the solvent 64 inside to the solvent tank 61 via the supply pipe 63.

  In a state where the solvent is stored in the solvent tank 61, the nozzle surface 48 of the inkjet head 42 is positioned above the upper opening of the solvent tank 61 by the X direction moving mechanism and the Y direction moving mechanism 45 (FIG. 2), and then the Z direction. By lowering by the moving mechanism 44 (FIG. 2), the nozzle surface 48 of the inkjet head 42 is immersed in the solvent 64 of the solvent tank 61 as shown in FIG. 7B. Thereby, it is possible to prevent the nozzle injection port 50 provided on the nozzle surface 48 from being dried.

  As shown in FIG. 8A, the solvent injection unit 70 includes a solvent injection unit 71 provided in a container 71, and a solvent storage for supplying a solvent 76 such as isopropyl alcohol (IPA) to the solvent injection unit 71. And a tank 75. The solvent storage tank 75 stores the solvent 76 therein and applies a positive pressure from the outside to supply the solvent 76 inside the solvent injection unit 72 via a supply pipe 77.

  A container 71 having a solvent injection unit 72 is supported by an actuator 79 fixed to a support frame 78 so as to be movable up and down in the Z direction. In the container 71, an opening 73 is provided at an upper portion in the injection direction of the solvent injection unit 72, and a packing 74 is provided on the outer wall portion of the container 71 at a position surrounding the opening 73.

  After the nozzle surface 48 of the inkjet head 42 is positioned above the opening 73 of the container 71 by the X direction moving mechanism and the Y direction moving mechanism 45 (FIG. 2), the container 71 is raised in the Z direction by the actuator 79, thereby As shown in FIG. 8B, the nozzle surface 48 of the inkjet head 42 is opposed to the opening 73 of the container 71 through the packing 74. In this state, the solvent 76 stored in the solvent storage tank 75 is supplied to the solvent injection unit 72, whereby the solvent 76 is injected from the solvent injection unit 72 to the nozzle surface 48 through the opening 73. Thereby, the nozzle surface 48 can be cleaned.

  As shown in FIG. 9A, the suction unit 80 includes a suction unit 82 having a suction hole 81 penetrating in the vertical direction, and a suction tank 84 that applies a negative pressure to the suction hole 81 of the suction unit 82. I have. The lower opening of the suction hole 81 of the suction unit 82 and the suction tank 84 communicate with each other via a suction pipe 83. By applying a negative pressure to the suction tank 84 from the outside, the suction hole is connected via the suction pipe 83. A negative pressure can be applied to 81.

  The upper portion of the suction hole 81 has an opening shape slightly larger than the shape of the nozzle surface 48 of the inkjet head 42, and the nozzle surface 48 of the inkjet head 42 is inserted into this opening portion. That is, after the nozzle surface 48 of the inkjet head 42 is positioned above the upper opening of the suction hole 81 by the X-direction moving mechanism and the Y-direction moving mechanism 45 (FIG. 2), it is lowered by the Z-direction moving mechanism 44 (FIG. 2). As a result, the nozzle surface 48 of the inkjet head 42 is inserted into the upper opening of the suction hole 81 as shown in FIG. In this state, a slight gap is formed between the inner wall surface of the suction hole 81 and the side surface of the ink jet head 42, so that when negative pressure is applied to the suction hole 81, external air is passed through this gap. Is sucked into the through hole 81. As a result, it is possible to remove the solvent, foreign matter, and the like attached to the nozzle surface 48 of the inkjet head 42.

[Composition of abandoned part]
In FIG. 1, the inkjet coating apparatus 1 is provided with an ejection target (discarding pad 92) for discarding ink droplets separately from the substrate 30 that is the target for applying ink droplets. It is designed to be thrown away. That is, between the columns 33a and 33b erected on the gantry 2, a support plate 91 of the throwing-out portion 90 is horizontally mounted, and a plurality of guide grooves extend in the Y direction on the upper surface of the support plate 91. It is installed. A guide protrusion (not shown) provided on the lower surface of the discard pad 92 is engaged with the guide groove, whereby the discard pad 92 is guided by the guide groove and is movable in the Y direction. It is supported. The throwing pad 92 is moved in the Y direction along the guide groove by a driving mechanism using a Y direction moving motor (not shown).

  As shown in FIG. 10A, in a state where the throwing pad 92 is guided to the guide groove of the support plate 91 and moved to the position retracted from the lower side of the inkjet head 42, the application target is placed below the inkjet head 42. When a certain substrate 30 is exposed, ink droplets can be applied to the substrate 30 by the inkjet head 42. On the other hand, as shown in FIG. 10B, in the state in which the discarding pad 92 is guided by the guide groove of the support plate 91 and moves below the inkjet head 42, the discarding pad 92 is In this state, the ink droplets ejected from the inkjet head 42 are applied to the throwing pad 92 without being applied to the substrate 30.

  When the ink application is stopped for a short time in the step of applying the ink droplets to the substrate 30, the control unit 10 (FIG. 4) moves the discard pad 92 below the ink jet head 42 to perform ink jetting. Ink droplets are ejected from the head 42. Thereby, drying of the nozzle 50 can be suppressed even during the ink application process.

[Coating process]
In the inkjet coating apparatus 1, when the coating process is completed, the control unit 10 immerses the nozzle surface 48 of the inkjet head 42 in the solvent 64 stored in the immersion tank 61 (FIG. 7) of the immersion unit 60. Prevent drying of 50.

  Then, when entering the ink application step, as shown in FIG. 11, the control unit 10 executes a startup maintenance process of the inkjet head 42 in step S11. In the start-up maintenance process, as shown in FIG. 12, the control unit 10 lifts the inkjet head 42 immersed in the immersion tank 61 from the immersion tank 61 in step S21, and then proceeds to step S22.

  In step S <b> 22, the control unit 10 cleans the nozzle surface 48 by ejecting the solvent onto the nozzle surface 48 of the inkjet head 42 by the solvent ejecting unit 70, thereby removing foreign matter or solvent adhering to the nozzle surface 48. Remove residue.

  Furthermore, the control part 10 moves to step S23, and removes the solvent adhering to the nozzle face 48 by sucking the nozzle face 48 with the suction part 80 (FIG. 9). As a result, ink droplets are stably ejected from the nozzle 50.

  In this state, the control unit 10 moves to step S25, adjusts the application position by the application position adjustment unit 5, and then returns from step S25 to the main routine of the application process shown in FIG.

  When returning to the main routine, the controller 10 starts applying ink droplets to the substrate 30 in step S12. In the case of this embodiment, as shown in FIG. 13, the substrate 30 to which ink droplets are applied is a substrate for a color filter of a liquid crystal panel, and a non-display region around the display region AR0 on the substrate 30. A black ink is applied to AR1 to form a light blocking layer that blocks light from the backlight. When the application process is started, the control unit 10 continues to give a sub-pulse to the piezoelectric element of the inkjet head 42, thereby shaking the liquid surface of the nozzle 50 to suppress drying of the ink.

  After starting the application process in step S12, the control unit 10 determines whether or not to stop ink application in step S13. If a negative result is obtained here, this means that the ink application process for one substrate 30 has not been completed, and the control unit 10 returns to step S12 and continues the application process. On the other hand, if a positive result is obtained in step S13, this means that, for example, the application of the ink droplets to one substrate 30 is completed, and the application of the ink droplets is shortened by replacing the substrate 30 or the like. The control unit 10 moves to step S14 and moves the discard pad 92 below the inkjet head 42 by the discard unit 90 (FIG. 10). Discard the ink droplets. Thus, even when the ejection of ink droplets is paused for a short time, drying of the nozzles 50 can be suppressed by discarding the ink droplets in the meantime.

  When the discarding process is completed, the control unit 10 proceeds to step S15 and determines whether or not to restart the coating process. If a positive result is obtained here, this means that, for example, the replacement of the substrate 30 is completed and the coating process can be resumed, and the control unit 10 returns to the above-described step S12 and returns to the ink liquid. Restart application of drops.

  On the other hand, if a negative result is obtained in step S15, this means that, for example, the replacement of the substrate 30 has not been completed, or the ink application process has ended, and the control unit 10 proceeds to step S16. Move.

  In step S16, the control unit 10 determines whether or not to end the coating process. If a negative result is obtained here, this means, for example, that the substrate 30 is being replaced and the coating process is not completed, and the control unit 10 returns to the above-described step S14 and performs the discarding process. repeat. On the other hand, if a positive result is obtained in step S16, this means that, for example, the application of ink droplets to all the substrates 30 has been completed, and the control unit 10 proceeds to step S17. The nozzle surface 48 of the inkjet head 42 is immersed in the solvent 64 of the immersion tank 61 by the immersion unit 60. As a result, when the ink application process is completed, the nozzle surface 48 is immersed in the solvent, and drying of the nozzle 50 is prevented.

  As described above, in the ink jet coating apparatus 1 according to the present embodiment, when the ink droplets are applied to the substrate 30, the nozzle surface 48 of the ink jet head 42 is washed so that the ink is discharged from the nozzle 50. Droplets can be ejected stably. Further, after the ink application process is completed, the nozzle 50 can be prevented from drying by immersing the nozzle surface 48 of the inkjet head 42 in the solvent tank 61 in which the solvent is stored.

  Further, when the application of ink droplets is paused for a short time, for example, when the substrate 30 is replaced in the coating process, the drying of the nozzles 50 is suppressed by discarding the ink droplets against the disposal pad 92. be able to. Furthermore, drying of the nozzle 50 can be suppressed by constantly giving a sub-pulse to the piezoelectric element of the ink jet head 42 in the coating process to shake the liquid surface of the nozzle 50.

  As a result, the ink jet coating apparatus 1 can always stably apply ink droplets.

(Other embodiments)
In the first embodiment described above, the suction surface 80 is used to suck the nozzle surface 48 to remove the solvent and foreign matter adhering to the nozzle surface 48, but instead of the suction portion 80. As shown in FIG. 14, a wiping portion 100 for wiping the nozzle surface 48 may be provided. 14A, the wiping unit 100 is disposed in a part of the maintenance unit 4 (FIG. 1), and positions the feeding roller 102 wound with the nonwoven fabric 101 and the nonwoven fabric 101 fed from the feeding roller 102. A guide roller 102 that winds up the nonwoven fabric 101, and a tension mechanism 106 that biases the guide roller 103 upward by a spring 105. The take-up roller 104 is rotated by a drive mechanism (not shown) using a motor to take up the nonwoven fabric 101.

  In a state where the nonwoven fabric 101 is positioned by the guide roller 103, the control unit 10 (FIG. 1) moves the nozzle surface 48 of the inkjet head 42 above the guide roller 103 by the X direction moving mechanism and the Y direction moving mechanism 45 (FIG. 2). After positioning, the nozzle surface 48 of the inkjet head 42 is brought into contact with the nonwoven fabric 101 positioned on the guide roller 103 as shown in FIG. 14B by being lowered by the Z-direction moving mechanism 44 (FIG. 2). In this state, the winding roller 104 is rotated to move the nonwoven fabric 101 from the feeding roller 102 to the winding roller 104 via the guide roller 103, so that the nonwoven fabric 101 moves while being in contact with the nozzle surface 48. Thereby, the nozzle surface 48 is wiped off by the nonwoven fabric 101. By wiping the nozzle surface 48 in this manner, it is possible to remove the solvent and foreign matter adhering to the nozzle surface 48 in the same manner as when sucking by the suction portion 80 (FIG. 9).

  Further, instead of the suction unit 80 of the first embodiment described above, the solvent or foreign matter adhering to the nozzle surface 48 may be removed by performing air blowing on the nozzle surface 48. In this case, for example, as shown in FIG. 15A, a gas injection unit 110 for injecting gas is provided in a part of the maintenance unit 4 (FIG. 1), and the inkjet head 42 is positioned on the gas injection unit to supply gas. Try to spray. The gas injection unit 110 includes a gas injection nozzle 111 fixed to the frame of the maintenance unit 4 and a valve 112 that supplies gas to the gas injection nozzle 111. The control unit 10 (FIG. 1) includes an X-direction moving mechanism. 15B by positioning the nozzle surface 48 of the inkjet head 42 above the gas ejection nozzle 111 by the Y direction moving mechanism 45 (FIG. 2) and then lowering it by the Z direction moving mechanism 44 (FIG. 2). As shown in FIG. 5, the nozzle surface 48 of the inkjet head 42 is brought close to the gas injection nozzle 111, and the valve 112 is opened in this state, whereby gas is sprayed onto the nozzle surface 48. As a result, the solvent and foreign matter adhering to the nozzle surface 48 can be removed in the same manner as in the case of suction by the suction unit 80 (FIG. 9).

  Further, two or more of suction by the suction unit 80, wiping by the wiping unit 100, and air blow by the gas injection unit may be used in combination.

  In the first embodiment described above, the case where the discard pad 92 is moved below the inkjet head 42 to execute the discard pad is described. For example, the discard pad 92 is disposed in the maintenance unit 4. The ink jet head 42 may be moved above the discard pad 92 to execute discard.

  In the first embodiment described above, the case where the nozzle surface 48 of the ink jet head 42 is cleaned by the maintenance unit 4 at the time of activation has been described. However, in the coating process, for example, when the substrate 30 is replaced, the nozzle surface may be changed as needed. You may make it perform 48 washing | cleaning. In addition, the landing position of the ink droplet is periodically measured by the application position adjusting unit 5, and when the landing diameter becomes smaller than a predetermined size set in advance, the nozzle surface 48 is cleaned by the maintenance unit 4. It may be. In this case, the application position adjustment described above with reference to FIG. 4 may be performed.

  Further, for example, a cap that is supported so as to be able to advance and retreat between a position covering the nozzle surface 48 and a position retracted from the covering position is provided, and the nozzle surface 48 is covered with the cap while the ejection of ink droplets is stopped, thereby You may make it suppress 50 drying.

It is a perspective view which shows the inkjet coating apparatus which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the inkjet head unit of the inkjet coating apparatus of FIG. It is a perspective view which shows the inkjet head of the inkjet coating apparatus of FIG. It is a block diagram which shows the control part of the inkjet coating apparatus of FIG. It is a basic diagram with which it uses for description of the adjustment process by the application position adjustment part in the inkjet coating device of FIG. It is a basic diagram which shows the maintenance part and inkjet head in the inkjet coating apparatus of FIG. It is sectional drawing which shows the immersion part in the inkjet coating apparatus of FIG. It is sectional drawing which shows the solvent injection part in the inkjet coating device of FIG. It is sectional drawing which shows the suction part in the inkjet coating device of FIG. It is a side view which shows the throwing-away part 90 in the inkjet coating device of FIG. It is a flowchart which shows the process sequence of the control part in the inkjet coating device of FIG. It is a flowchart which shows the maintenance process procedure at the time of starting of FIG. It is a basic diagram which shows application | coating treatment of an ink droplet. It is a side view which shows the wiping part which concerns on other embodiment. It is a side view which shows the gas injection part which concerns on other embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Inkjet coating device, 2 ... Stand, 3 ... Ink application part, 4 ... Maintenance part, 10 ... Control part, 11 ... Ink jet control circuit, 12 ... Motor drive circuit, 13 ... Y direction counter, 14 ... X direction counter 15 ... θ direction counter, 18 ... nozzle drive circuit, 30 ... substrate, 40 ... inkjet head unit, 42 ... inkjet head, 48 ... nozzle surface, 50 ... nozzle, 60 ... immersion part, 70 ... solvent injection part, 80 ... Suction part, 90 ... discarding part, 100 ... wiping part, 110 ... gas injection part.

Claims (5)

A cleaning mechanism for cleaning the nozzle surface of the inkjet head having a nozzle surface provided with a nozzle injection port which is an opening for ejecting droplets;
A control unit that executes the cleaning process of the nozzle surface by the cleaning mechanism depending on the application process of the droplets to the application target of the droplets;
An inkjet coating apparatus comprising: The cleaning mechanism is
An injection mechanism for injecting the solvent of the droplets onto the nozzle surface;
A suction mechanism for sucking the nozzle surface;
The inkjet coating apparatus according to claim 1, further comprising: The cleaning mechanism is
An injection mechanism for injecting the solvent of the droplets onto the nozzle surface;
A wiping mechanism for wiping the nozzle surface;
The inkjet coating apparatus according to claim 1, further comprising: An immersion mechanism for immersing the nozzle surface in the solvent of the droplets stored in the solvent tank;
2. The inkjet coating apparatus according to claim 1, wherein the control unit immerses the nozzle surface in the solvent by the dipping mechanism after the coating process is finished. In addition to the application target, provided with a target for jetting the droplets,
2. The inkjet coating apparatus according to claim 1, wherein the control unit performs ejection of the droplet onto the ejection target during the coating process of the droplet onto the coating target.

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