JP2006088074A - Ink jet coater and coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet coater capable of keeping an ink discharging state from a nozzle to be always good while avoiding a break down or an attrition failure of an opening end side of a nozzle by contact with a shutter. <P>SOLUTION: The ink jet coater has an ink jet head 42 having a nozzle outlet 50 which is an opening for spraying drops, the shutter 51 arranged movably forwards and backward as to cover the nozzle outlet near the nozzle outlet 50, and a supporting mechanism 49, 52, 53 for moving the shutter 51 while keeping a gap for the opening end side of the nozzle outlet 50 between a position covering the nozzle outlet 50 and a position evacuated from the said position. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet coating apparatus and a coating method for discharging ink droplets to apply ink to a coating target.

  Conventionally, in a personal computer or 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), and B (blue) are applied to each dot on a transparent substrate by using a so-called inkjet coating device designed to eject minute droplets from nozzles. ) In order to create a color filter in which dots of each color are sequentially arranged.

  In recent years, organic EL (electroluminescence) displays have been used as display devices that replace liquid crystal displays. In the manufacturing process of the organic EL display, R, G, and B inks obtained by dissolving a light-emitting polymer material in an organic solvent are applied onto a transparent substrate by an inkjet coating device, respectively. A light emitting region is formed on the transparent substrate by sequentially arranging dots corresponding to the respective colors of B.

  By the way, in the manufacturing process of these display devices, after moving an inkjet head having a nozzle for ejecting ink to a position facing a coating start position of a substrate to be coated, the relative position of the inkjet head and the substrate is moved. Ink is sequentially ejected from the nozzles at a predetermined application position. Therefore, while changing the substrate to be coated, the ink ejection is paused while the inkjet head is moved to the ink application start position at the start of coating and while the inkjet head is moved to the retracted position when the substrate is replaced. As a result, the pause time becomes longer as the size of the substrate to be coated increases.

  In addition, in an inkjet coating apparatus having a plurality of inkjet heads, such as for each color of R, G, and B, when ink ejection from other inkjet heads is suspended while coating with one inkjet head In other words, this pause time becomes longer as the application area increases.

  When the time during which the ink application is stopped becomes longer in this way, the ink in the nozzles of the inkjet head dries and the dried ink causes the nozzles to become clogged. As a result, the required amount of droplets is ejected. In some cases, it is difficult to discharge ink, and when the nozzles are completely clogged, it may be difficult to eject ink.

  As one measure for solving this problem, a method using ink having a long drying time is considered. According to this method, it is considered that the drying of the ink of the nozzle can be delayed, and the occurrence of ejection failure can be prevented even when the ejection pause time is extended.

  However, if the drying time is lengthened, the finishing accuracy when the ink applied on the substrate dries may be deteriorated. Also, the longer the drying time, the longer the time required for the coating process, and the manufacturing process of the display device. As a whole, the production efficiency was lowered, and the solution was still insufficient.

In addition, for example, an ink jet printer in which a nozzle is capped with a cap after printing has been proposed (see Patent Document 1). According to this ink jet printer, it is considered that drying of ink in the nozzle can be suppressed by sealing the nozzle opening with the cap.
JP-A-7-76092 (FIG. 4)

  However, according to the method of Patent Document 1, the cap is in contact with the opening end surface of the nozzle discharge port, and there is a problem that the opening end surface of the nozzle discharge port is damaged when the cap is opened and closed. There was a problem that the surface treatment layer applied to the surface deteriorated due to contact with the cap during the opening and closing operation of the cap. In addition, when the cap is further closed, the ink remaining in the nozzle discharge port adheres to the cap, and this adhering ink dries and obstructs the opening and closing operation of the cap, and the ink attached to the cap adheres to the nozzle discharge port. As a result, there was a problem that the nozzle was clogged.

  The present invention has been made to solve such a technical problem, and an object of the present invention is to prevent damage to the opening end face of the nozzle discharge port due to contact with the shutter or deterioration of wear, while avoiding damage from the nozzle. It is an object to provide an ink jet coating apparatus and a coating method capable of always maintaining a good ink discharge state.

  A first feature according to an embodiment of the present invention is that, in an ink jet coating apparatus, an ink jet head having a nozzle discharge port that is an opening for ejecting droplets, and the nozzle discharge port is covered in the vicinity of the nozzle discharge port. A shutter that is provided so as to be able to advance and retreat, and a support mechanism that moves the shutter with respect to the opening end face of the nozzle discharge port between a position that covers the nozzle discharge port and a position that is retracted from the covered position. is there.

  A second feature according to the embodiment of the present invention is that, in the inkjet coating apparatus according to the first feature, the distance between the position covering the nozzle discharge port of the shutter supported by the support mechanism and the opening end surface of the nozzle discharge port is The maximum size for maintaining the solvent atmosphere at the nozzle outlet is set to be equal to or smaller than the maximum size.

  A third feature according to the embodiment of the present invention is that, in the coating method, in the vicinity of the nozzle discharge port which is an opening for ejecting droplets, a shutter provided to be able to advance and retreat so as to cover the nozzle discharge port is provided. It moves from the position covering the discharge port to the retracted position, and sprays droplets from the nozzle discharge port to apply the droplets to the application target, and stops the droplet ejection and opens the nozzle discharge port. And a coating suspension step of moving the shutter to a position covering the nozzle discharge port while maintaining a gap with the end surface.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress the drying of the ink of a nozzle, avoiding the failure | damage of the opening end surface of a nozzle by contact with a shutter, or wear deterioration.

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

(First embodiment)
As shown in FIG. 1, the ink jet coating apparatus 1 according to the first embodiment of the present invention includes an ink coating box 3 provided on the upper surface of the gantry 2 and ink replenishment for refilling the ink coating box 3. 2 and 4, the ink application box 3 includes an inkjet head 42 having a nozzle ejection port 50 that is an opening for ejecting droplets, and a nozzle ejection port. In the vicinity of 50, the shutter 51 is provided at the opening end surface of the nozzle discharge port 50 between a shutter 51 provided so as to be able to advance and retract so as to cover the nozzle discharge port 50, and a position where the nozzle discharge port 50 is covered and a position retracted from the covered position. Support mechanisms 49, 52, and 53 that move with a gap to a nozzle surface 48 are provided.

  That is, as shown in FIG. 1, in the ink application box 3, a Y-axis direction guide plate 20 is fixed to the upper surface of the gantry 2, and a plurality of Y-axis direction guide plates 20 are arranged on the upper surface of the Y-axis direction guide plate 20. A guide groove 21 is extended. A guide projection (not shown) provided on the lower surface of the Y-axis direction moving table 22 is engaged with the guide groove 21, whereby the Y-axis direction moving table 22 is guided by the guide groove 21. It is supported so as to be movable in the Y-axis direction. The Y-axis direction moving table 22 is moved in the Y-axis direction along the guide groove 21 by a driving mechanism using a motor, for example.

  A plurality of guide grooves (not shown) extend in the X-axis direction on the upper surface of the Y-axis direction moving table 22. A guide projection (not shown) provided on the lower surface of the X-axis direction moving table 23 is engaged with the guide groove, whereby the X-axis direction moving table 23 is guided by the guide groove. It is supported so as to be movable in the X-axis direction. The X-axis direction moving table 23 is moved in the X-axis direction along the guide groove by, for example, a drive mechanism using a motor.

  A substrate holding table 26 is fixed to the upper surface of the X-axis direction moving table 23, and the substrate 30 that is the object of ink application can be held and fixed to the upper surface of the substrate holding table 26 by a gripping mechanism 27. It is made like that. Note that the method for fixing the substrate 30 may be, for example, a method of sucking by the suction mechanism instead of the gripping by the gripping mechanism 27.

  In the ink application box 3, a pair of columns 33 a and 33 b are erected on the top surface of the gantry 2 at a position sandwiching the Y-axis direction slide plate 20, and an X-direction guide is disposed above the columns 33 a and 33 b. 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 driving mechanism using a motor, for example.

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

  In addition, three ink jet head units 40 for R (red), G (green), and B (blue) are suspended from the base plate 41, and the ink jet head unit 40 is provided at the lower end thereof. Ink is ejected downward by the ink jet head 42.

  That is, as shown in FIG. 2, in the inkjet head unit 40, a Z-axis direction moving mechanism 44 that is supported by the base plate 41 and supports the moving unit 44 a movably in the Z-axis direction (vertical direction), and the Z-axis A Y-axis direction moving mechanism 45 supported by the moving unit 44a of the direction moving mechanism 44 and movably supporting the moving unit 45a in the Y-axis direction, and a rotating unit supported by the moving unit 45a of the Y-axis direction moving mechanism 45. A θ-direction rotation mechanism 46 that rotatably supports 46a in the θ-direction, which is a rotation direction around the Z-axis direction, and an inkjet head 42 that is suspended by the rotation portion 46a of the θ-direction rotation mechanism 46, and has a Z-axis The direction moving mechanism 44 can adjust the position of the inkjet head 42 in the Z-axis direction with respect to the substrate 30, and the Y-axis direction moving mechanism 45 can adjust the position of the inkjet head 42. Together may be adjusted in the Y-axis direction with respect to the substrate 30, the orientation of the ink jet head 42 are adapted to be rotated in the direction θ relative to the substrate 30 by θ rotating mechanism 46.

  As described above, in the inkjet head unit 40, the position of the inkjet head 42 relative to the substrate 30 held on the substrate holding table 26 can be variously adjusted.

  The ink application box 3 is provided with three inkjet head units 40 corresponding to the respective colors. These inkjet head units 40 have the same configuration.

  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 have nozzle discharge ports 50 directed downward on the nozzle surface 48 directed downward. Are drilled in series. As a result, the nozzle surface 48 constitutes the open end surface of the nozzle. Further, the nozzle discharge ports 50 are arranged at a predetermined interval from each other. In FIG. 3, an opening / closing mechanism of the shutter 51 described later is omitted.

  An ink tank communicating with each nozzle is provided inside the inkjet head 42, and a diaphragm is provided on the upper surface of the ink tank. The diaphragm is driven by an ejection control signal from the control unit 10 to change the pressure in the ink tank and eject 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.

  The control unit 10 controls driving of a motor for moving the Y-direction movement table 22, a motor for moving the X-direction movement table 23, and a motor for moving the base plate 41 based on data representing the application position. Thus, the movement of the Y-direction moving table 22 in the Y-axis direction, the movement of the X-direction moving table 23 in the X-axis direction, and the movement of the base plate 41 in the X-axis direction are controlled. As a result, the control unit 10 discharges ink from the nozzle discharge ports 50 of the inkjet head 42 while changing the relative position between the substrate 30 held on the substrate holding table 26 and the inkjet head 42, whereby a predetermined amount of the substrate 30 is determined. Ink can be applied sequentially to the positions.

  In the ink jet head 42, it moves between a position covering the nozzle surface 48 (hereinafter referred to as a closed position) and a position retracted laterally from this position (hereinafter referred to as an open position). A shutter 51 made of a glass plate is supported freely.

  That is, as shown in FIG. 4, a frame-shaped frame cover 49 made of a resin material protruding by a predetermined height below the nozzle surface 48 is fixed around the nozzle surface 48 of the inkjet head 42. In addition, guide members 52 and 53 are provided at both end portions of the nozzle surface 48 in a direction substantially parallel to the nozzle surface 48 that forms the opening end surface of the nozzle discharge port 50.

  In the shutter 51, a notch 51a extending in the moving direction of the shutter 51 is formed on one side edge portion of the shutter 51, and a guide member 53 is slidably engaged with the notch 51a. . In this engaged state, the shutter 51 is sandwiched between the guide member 53 and the frame cover 49. The other side edge of the shutter 51 is sandwiched between the guide member 52 and the frame cover 49. Thus, the guide members 52 and 53 and the frame cover 49 constitute a support mechanism for the shutter 51, and the shutter 51 moves along the guide members 52 and 53 between a closed position and an open position. Has been made. 5A and 6A show a state in which the shutter 51 is in a closed position, and FIGS. 5B and 6B show a state in which the shutter 51 is in an open position. .

  A motor 55 is fixed to the side surface of the inkjet head 42, and a pinion gear 57 is fitted on the rotation shaft of the motor 55. On the other hand, a rack 58 is extended on the upper surface of the shutter 51 in the moving direction of the shutter 51, and a pinion gear 57 on the motor 55 side is engaged with the rack 58. Thus, the motor 55 is driven to rotate by a control signal output from the control unit 10 that controls the ink jet coating apparatus 1, thereby moving the shutter 51 along the guide members 52 and 53 using the motor 55 as a drive source. Can do.

  In this way, by opening and closing the shutter 51 in a direction substantially parallel to the nozzle surface 48 constituting the opening end surface of the nozzle discharge port 50, the fluctuation of the atmospheric pressure applied to the ink inside the nozzle when the shutter 51 is opened and closed. Accordingly, it is possible to prevent bubbles from being mixed into the ink, thereby preventing ink ejection failure.

  Here, the height of the frame cover 49 interposed between the shutter 51 and the nozzle surface 48 is determined based on the components of the inkjet head 42 and the processing and assembly accuracy of the nozzle surface 48, and the upper surface of the shutter 51 and the nozzle surface 48. It is comprised so that it may become more than the minimum magnitude | size which does not contact. Therefore, when the shutter 51 is closed, the peripheral portion of the upper surface of the shutter 51 contacts the frame cover 49 so that the shutter 51 and the nozzle surface 48 do not come into contact with each other. Further, even when the shutter 51 is opened and closed between the closed position and the opened position, the shutter 51 and the nozzle surface 48 come into contact with each other because the frame cover 49 is interposed between the shutter 51 and the nozzle surface 48. It is made not to do.

  As described above, the ink jet head 42 is configured to avoid contact between the shutter 51 and the nozzle surface 48, thereby preventing the nozzle surface 48 from being damaged or worn out.

  When the shutter 51 is closed, the frame cover 49 forms a minute gap determined by the height of the frame cover 49 between the upper surface of the shutter 51 and the nozzle surface 48. The size of the gap is configured to be not more than the maximum size that can maintain the solvent atmosphere of the nozzle discharge port 50.

  As described above, in the ink jet head 42, the environment in which the nozzle surface 48 is in contact with the gap space formed between the shutter 51 and the nozzle surface 48 is maintained in the solvent atmosphere by the ink in the nozzle when the shutter 51 is closed. Accordingly, it is possible to prevent the ink at the nozzle discharge port 50 from being easily dried.

  Incidentally, in the case of this embodiment, the diameter of the nozzle hole is φ20 μm to φ80 μm, the gap between adjacent nozzles on the nozzle surface 48 is 1 mm, and the number of nozzle holes is 60. Is set to 0.1 mm, and the upper limit of the gap set for the purpose of maintaining the solvent atmosphere is set to several mm.

  When the shutter 51 is moved to the open position along the guide members 52 and 53, each nozzle discharge port 50 of the nozzle surface 48 is exposed downward, and ink is discharged from the nozzle discharge port 50 in this state. As a result, ink can be applied to the substrate 30 held below the nozzles.

  Here, when ink is ejected from the nozzle ejection port 50, the ink may remain on the nozzle surface 48 around the nozzle ejection port 50. The remaining ink adheres to the upper surface of the shutter 51 when the shutter 51 is closed, and directly touches the outside air when the shutter 51 is opened. In this way, the remaining ink that has been in direct contact with the outside air is dried. When the shutter 51 is closed again, there is a possibility that the remaining ink adheres so as to cover the nozzle discharge port 50 and the nozzle is clogged. Therefore, in the inkjet coating apparatus 1, as shown in FIG. 7, a cleaning unit 60 is provided on the side surface of the inkjet head 42 as a removing mechanism for removing foreign matters such as residual ink adhering to the upper surface of the shutter 51. Yes. In the cleaning unit 60, an absorbent paper or cloth cleaning member 61 is disposed on the upper part of the movement path of the shutter 51, and the upper surface of the shutter 51 comes into contact with the cleaning member 61 when the shutter 51 is opened. It is made like that. Thus, every time the shutter 51 is opened, the upper surface of the shutter 51 is wiped off by the cleaning member 61, and foreign matters such as residual ink are removed.

  Such removal of foreign matter by the cleaning unit 60 is performed every time the shutter 51 is opened and closed.

  Here, in the control unit 10 that controls the ink jet coating apparatus 1, the shutter 51 is opened at the timing when ink is ejected from the ink jet head 42, and ink is ejected while changing the relative position between the substrate 30 and the ink jet head 42 in this state. repeat. When, for example, the application of one row of ink to the substrate 30 is completed, the control unit closes the shutter 51 and changes the relative position between the substrate 30 and the ink jet head 42 to the top position of the next row and then the shutter again. 51 is opened and ink discharge is started. When ink is applied to the substrate 30 as described above, there is an application pause process in which the ejection of ink is paused for a relatively short time even during a series of application processes, and the shutter 51 is closed in such an application pause process. As a result, the nozzle can be prevented from being easily dried, and foreign matter such as residual ink on the upper surface of the shutter can be removed by the cleaning unit 60 by opening the shutter 51 when discharging is started again.

  As described above, in the ink jet head 42, the shutter 51 is closed during the ink discharge suspension period, so that the ink at the nozzle discharge port 50 can be prevented from being easily dried to prevent clogging of the nozzle. The cleaning unit 60 can remove foreign matters such as residual ink on the upper surface of the shutter 51 to prevent nozzle clogging.

  Further, in the inkjet coating apparatus 1, as shown in FIGS. 8 to 10, for example, when the ejection of ink is stopped for a relatively long time, for example, when the substrate 30 is replaced, the inkjet head 42 in which the shutter 51 is closed. Is brought into contact with a solvent to shield the nozzle surface 48 from the outside air and prevent the ink of the nozzle from drying. That is, in the ink application box 3 of the inkjet coating apparatus 1, the solvent tank 70 is provided on the top of the gantry 2. The solvent tank 70 is held by a moving table 71 supported at the upper part of the gantry 2 so as to be movable in the front-rear direction. The solvent tank 70 is moved forward from the position below the inkjet head 42 by the movement of the moving table 71 and retracted from this position. It is designed to be able to move between positions. The movement table 71 is movement-controlled by the control unit 10 using a motor as a drive source. The inkjet head 42 is controlled to move in the X-axis direction by a mechanism (X-direction guide plate 35, guide groove 36, base plate 41) that moves the inkjet head unit 40 described above with reference to FIG. 1 in the X-axis direction. 2 is controlled to move in the Z-axis direction by the Z-axis direction moving mechanism 44 described above. The ink jet head 42 and the solvent tank 70 can be moved relatively by the moving mechanism of the solvent tank 70 and the moving mechanism of the ink jet head unit 40.

  In the state where the solvent tank 70 is moved from the lower side of the inkjet head 42 to the position retracted, the substrate 30 is disposed below the inkjet head 42, and ink is ejected onto the substrate 30 by the inkjet head 42. Can do. In a state where the solvent tank 70 is advanced below the ink-jet head 42, the ink-jet head unit 40 is moved to the upper part of the solvent tank 70 by the moving mechanism in the X-axis direction, and then the ink-jet is moved by the Z-axis moving mechanism 44. By moving the head 42 in the Z-axis direction, the inkjet head 42 can be moved into the solvent tank 70.

  Ink solvent is stored in the solvent tank 70. By immersing the lower end portion of the inkjet head 42 with the shutter 51 closed in the solvent tank 70, the nozzle surface 48 is shielded from the outside air and the solvent atmosphere is kept. Can keep.

  That is, as shown in FIG. 8, at the time of ink application, the solvent tank 70 is moved from the lower side of the inkjet head 42 to a position retracted by the control of the control unit 10. In this state, the control unit 10 opens the shutter 51 of the inkjet head 42 and causes the inkjet head 42 to eject ink. When the ink application process is completed, as shown in FIG. 9, the shutter 51 is closed and the solvent tank 70 is advanced below the ink jet head 42. Further, as shown in FIG. The tip of the inkjet head 42 is immersed in the solvent tank 70 by being lowered by the vertical drive mechanism. In this case, the shutter 51 is in a closed state, and in this state, the gap space formed between the nozzle surface 48 and the shutter 51 is reliably shielded from the outside air.

  When starting the ink application process, the control unit 10 raises the inkjet head 42 immersed in the solvent tank 70 to pull up the tip of the inkjet head 42 from the solvent tank 70. At the same time, the shutter 51 is opened and ink is ejected.

  As described above, when the ejection of the ink is stopped for a relatively long time as in the replacement of the substrate 30, the nozzle surface 48 is made to be in a solvent atmosphere by immersing the tip of the inkjet head 42 in the solvent tank 70. The ink remaining in the nozzle discharge port 50 can be prevented from drying.

  Next, the operation of the inkjet coating apparatus 1 having the above-described configuration will be described. For example, when applying ink to each dot of the substrate 30 used in a display device such as a liquid crystal or an EL, the control unit 10 that controls the operation of the inkjet coating apparatus 1 uses the Y direction based on data representing the coating position. By moving the moving table 22, the X-direction moving table 23, and the inkjet head unit 40, the inkjet head 42 is positioned so as to face the ink application position of the substrate 30 held on the substrate holding table 26 from above.

  In this state, as shown in FIGS. 5A and 6A, the control unit 10 opens the shutter 51 to expose the nozzle discharge port 50, and then the relative relationship between the inkjet head 42 and the substrate 30 is reached. Ink is sequentially applied to each dot on the substrate 30 by ejecting ink from the nozzle ejection port 50 at a timing when the nozzle ejection port 50 coincides with a position facing the dot on the substrate 30 while moving the position.

  For example, when a series of ejection operations are completed as in the ejection process for one row of dots on the substrate 30, the control unit 10 positions the inkjet head 42 so as to face the application start position of the next dot row on the substrate 30. To do. As described above, in the ink application process, there is a pause period in which the ejection operation is paused for a relatively short time between a series of ink ejection operations. During this period, the control unit 10 performs the process illustrated in FIGS. As shown in FIG. 6B, the ink in the nozzles is prevented from easily drying by closing the shutter 51. When the shutter 51 is opened and closed and when the shutter 51 is closed, a frame cover 49 is interposed between the shutter 51 and the nozzle surface 48, so that a predetermined amount is provided between the shutter 51 and the nozzle surface 48. The gap is maintained, thereby avoiding breakage or wear deterioration of the nozzle face 48.

  Thus, by closing the shutter 51 so that the contact between the shutter 51 and the nozzle surface 48 is avoided, a gap is formed between the shutter 51 and the nozzle surface 48. The size of this gap is By being configured to be less than the maximum size that can maintain the solvent atmosphere, the gap space is maintained in the solvent atmosphere by the ink in the nozzle, and is provided on the nozzle surface 48 and the nozzle surface 48. The nozzle outlet 50 is not immediately in contact with the outside air. Thereby, drying of the ink of the nozzle outlet 50 is suppressed.

  Further, the gap space formed between the shutter 51 and the nozzle surface 48 when the shutter 51 is closed is covered with a frame cover 49 in a semi-sealed state, so that the solvent atmosphere is further extended for a long time. Will be maintained.

  When the shutter 51 is closed, the space between the shutter 51 and the frame cover 49 is not completely sealed. In this embodiment, the shutter 51 is made of a glass plate and the frame cover 49 is By being made of resin, the adhesion is further improved, and the ink drying is further suppressed accordingly.

  Further, after ink is ejected, ink may remain in the nozzle ejection port 50, but in this inkjet head 42, since the shutter 51 is not in contact with the nozzle surface 48, the remaining ink remains in the shutter 51. Easy adhesion is prevented. As a result, clogging of the nozzle discharge port 50 due to foreign matters such as residual ink adhering to the shutter 51 adhering to the nozzle discharge port 50 is prevented.

  Incidentally, when foreign matter such as residual ink adheres to the shutter 51, when the shutter 51 is opened, the foreign matter is removed by the cleaning unit 60 shown in FIG. It is possible to more effectively prevent foreign matters from adhering so as to block the nozzle discharge port 50.

  For example, when the ejection of ink is suspended for a relatively long time, such as when the substrate 30 to be coated is replaced, the tip of the inkjet head 42 is located in the solvent tank 70 as shown in FIGS. By being immersed in the solvent, the nozzle discharge port 50 of the inkjet head 42 is maintained in a solvent atmosphere, and drying thereof is prevented.

  Further, when the ink is not ejected, the nozzle surface 48 is covered with the shutter 51, so that, for example, when ink is dripped from the nozzle ejection port 50 due to vibration generated along with the movement of the inkjet head 42 during this period, Even when the nozzle malfunctions due to noise and ink is accidentally ejected, the closed shutter 51 prevents the ink from inadvertently dropping onto the substrate 30, thereby causing a defect in the substrate 30 in the ink application process. This will reduce the occurrence rate.

  According to the ink jet coating apparatus 1 described above, the shutter 51 is supported movably between a position covering the nozzle surface 48 constituting the opening end surface of the nozzle discharge port 50 and a position retracted from the covering position. By preventing the shutter 51 from coming into contact with the nozzle surface 48, drying of the ink at the nozzle discharge port 50 can be suppressed while avoiding damage to the nozzle surface 48 or deterioration of wear due to the shutter 51. In addition, by closing the shutter 51, inadvertent dripping of ink can be prevented. In addition, when the shutter 51 is closed, the size of the gap formed between the shutter 51 and the nozzle surface 48 is set to be equal to or smaller than the maximum size that can maintain the solvent atmosphere. It is possible to sufficiently suppress the drying of the ink of the nozzles while avoiding damage to the nozzle surface 48 or deterioration due to wear.

  In addition, a cleaning unit 60 is provided as a foreign matter removing means, and foreign matter such as residual ink attached to the shutter 51 is removed by the cleaning unit 60, so that the foreign matter can cause the nozzle discharge port 50 to open and close by the opening / closing operation of the shutter 51. It is possible to prevent a discharge failure from occurring due to the covering.

  Further, when the ink discharge is stopped for a relatively long time, the nozzle discharge port 50 is kept in the solvent atmosphere by immersing the tip of the inkjet head 42 in the solvent in the solvent tank 70. Ink drying can be prevented.

  As a result, according to the ink jet coating apparatus 1 of the present embodiment, it is possible to prevent nozzle clogging and to keep the ink ejection state from the nozzles always good.

  In the first embodiment described above, the case where the tip of the inkjet head 42 is immersed in the solvent in the solvent tank 70 with the shutter 51 closed while the ink application is suspended has been described. However, the present invention is not limited to this, and the solvent may be ejected to the tip of the inkjet head 42 with the shutter 51 closed. In this case, as a solvent ejection mechanism, a nozzle for ejecting the solvent is provided in the vicinity of the inkjet head 42, and when the ink application is stopped, the tip of the inkjet head 42 from which the shutter 51 is closed. The solvent may be sprayed on the surface. Even in this case, the gap space formed between the closed shutter 51 and the nozzle surface 48 can be shielded from the outside air.

  In the first embodiment described above, the case where the tip of the ink jet head 42 is immersed in the solvent in the solvent tank 70 while the ink application is stopped has been described. However, the present invention is not limited to this. The nozzle discharge port 50 may be pressurized and purged before the shutter 51 is closed, after the shutter 51 is closed, or while the shutter 51 is closed, so that ink is oozed out from the nozzle discharge port 50. In this way, the gap space formed between the shutter 51 and the nozzle surface 48 can be maintained in a solvent atmosphere, the drying of the nozzle discharge port 50 can be prevented, and ink caused by nozzle clogging can be prevented. Occurrence of ejection failure can be prevented.

  In the first embodiment described above, contact between the shutter 51 and the nozzle surface 48 is avoided according to the diameter of the nozzle hole, the gap between adjacent nozzles in the nozzle surface 48, and the number of nozzle holes. Although the case where the lower limit value of the gap set for the purpose is 0.1 mm and the upper limit value of the gap set for the purpose of maintaining the solvent atmosphere is described as several mm has been described, the present invention is not limited to this. The size of the gap is set to various dimensions according to the diameter of the nozzle holes, the interval between the nozzle holes, and the number of nozzle holes.

(Second Embodiment)
FIG. 11 is a partial cross-sectional view showing a tip portion of an ink jet head unit used in an ink jet coating apparatus according to the second embodiment of the present invention. Compared with the inkjet head unit in the first embodiment described above with reference to FIG. 4, the inkjet coating apparatus according to the second embodiment moves the tip of the inkjet head 42 of the solvent tank 70 during the rest of the ink coating. Instead of the structure for immersing in the solvent, only the structure for supplying the solvent gas to the gap space between the shutter 51 and the nozzle surface 48 when the shutter 51 is closed is different. . Therefore, in FIG. 11, the same reference numerals are given to corresponding parts to those in FIG. 4, and the duplicate description is omitted here. In FIG. 11, the guide members 52 and 53, the motor 55, the pinion gear 57, the rack 58, and the opening and closing mechanism of the shutter 51 such as the cleaning unit 60 described above with reference to FIG. 4 are omitted. It shall also have a configuration.

  That is, as shown in FIG. 11, an air supply hose 65 for supplying solvent gas is attached to the shutter 51 of the ink jet coating apparatus of the second embodiment. The distal end of the air supply hose is joined from the lower surface side of the shutter 51 to an air supply port 53 formed so as to penetrate a part of the shutter 51. Ink solvent gas is supplied from a solvent gas supply device 66 to the air supply hose 65. Thus, the solvent gas can be supplied to the upper surface side of the shutter 51 through the air supply hose 65 and the air supply port 53 of the shutter 51.

  In this case, in the control unit that controls the ink jet coating apparatus, the solvent gas supply device 66 and the drive mechanism of the shutter 51 are operated in a coordinated manner so that the solvent gas is supplied when the shutter 51 is closed. Thus, the solvent gas is supplied to the gap space between the shutter 51 and the nozzle surface 48.

  As a result, the gap space formed between the closed shutter 51 and the nozzle surface 48 can be maintained in a solvent atmosphere, and the ink at the nozzle discharge port 50 is prevented from drying, and ink caused by nozzle clogging. It is possible to prevent the occurrence of discharge failure.

(Third embodiment)
FIG. 12 is a partial cross-sectional view showing an ink jet head unit used in an ink jet coating apparatus according to the third embodiment of the present invention. The ink jet coating apparatus according to the third embodiment has a cleaning unit that removes foreign matters such as residual ink adhering to the upper surface of the shutter 51, as compared with the ink jet head unit according to the first embodiment described above with reference to FIG. The only difference is that a configuration for sucking a gap space formed between the shutter 51 and the nozzle surface 48 is provided in place of 60. Therefore, in FIG. 12, the same reference numerals are given to corresponding parts to FIG. 4, and the duplicate description is omitted here. In FIG. 12, the guide members 52 and 53, the motor 55, the pinion gear 57, the opening and closing mechanism of the shutter 51 such as the rack 58 described above with reference to FIG. 4 are omitted, but these configurations are also included. And

  That is, as shown in FIG. 12, an intake hose 67 for sucking the upper surface side of the shutter 51 is attached to the shutter 51 of the ink jet coating apparatus of the third embodiment. The tip of the suction hose 67 is joined from the lower surface side of the shutter 51 to a suction port 53 that is formed through a part of the shutter 51. By applying a negative pressure to the suction hose 67 by the suction device 68, the upper surface side of the shutter 51 can be sucked.

  In this case, in the control unit that controls the ink jet coating apparatus, the suction device 68 and the driving mechanism of the shutter 51 are operated in cooperation with each other so that suction is performed while the shutter 51 is closed, thereby A gap space formed between the nozzle surface 48 and the nozzle surface 48 can be sucked.

  By sucking the gap space formed between the shutter 51 and the nozzle surface 48 in this manner, foreign matter such as residual ink adhering to the upper surface of the shutter 51, the nozzle surface 48 and the nozzle discharge port 50 is sucked into the suction hose 67. It can be discharged to the outside. Thereby, it is possible to prevent the occurrence of ink ejection failure due to nozzle clogging.

  In the third embodiment, a configuration for suctioning between the shutter 51 and the nozzle surface 48 is provided in place of the cleaning unit 60 of the ink jet coating apparatus of the first embodiment. The present invention is not limited to this, and the cleaning unit 60 may be used in combination.

(Fourth embodiment)
FIG. 13 is a perspective view showing an ink jet head unit used in an ink jet coating apparatus according to the fourth embodiment of the present invention. The inkjet coating apparatus according to the fourth embodiment is replaced with a single shutter 51 that covers the entire plurality of nozzles of the nozzle surface 48 as compared with the inkjet head unit according to the first embodiment described above with reference to FIG. The only difference is that a shutter 151 that is divided into a plurality of shutter pieces 151a, 151b, and 151c is provided, and the shutter pieces 151a, 151b, and 151c are individually opened and closed. Therefore, in FIG. 13, the same reference numerals are given to corresponding parts to FIG. 4, and the duplicate description is omitted here. In FIG. 13, the opening / closing mechanism and the cleaning unit 60 for opening / closing the shutter pieces 151a, 151b, 151d are omitted. Among the shutter pieces 151a, 151b, and 151c constituting the shutter 151, the shutter pieces 151a and 151c on both sides are provided with the opening / closing mechanism (guide members 52 and 53, motor 55, pinion gear 57, and rack 58) described above with reference to FIG. Each is provided and individually opened and closed by the control unit, and the central shutter piece 151b is linked with, for example, a solenoid as a driving source because it is difficult to secure a space for providing the motor 55 and the rack 58. Another driving mechanism is used, such as opening and closing the shutter piece 151b under the control of the control unit via the mechanism.

  As shown in FIG. 13, the shutter 151 of the ink jet coating apparatus according to the fourth embodiment is divided into shutter pieces 151a, 151b, and 151c corresponding to a predetermined number of adjacent nozzles of the plurality of nozzle discharge ports 50. Each is individually driven to open and close.

  In the control unit that controls the ink jet coating apparatus according to the fourth embodiment, the shutter piece to be used is selected according to the coating pattern on the substrate 30 to be coated with ink, and the selected shutter piece is opened to supply ink. Discharge.

  If it does in this way, about the nozzle which is not used, it can always be set as the state covered with the shutter piece, and it can prevent that the nozzle which is not used dries.

  In the fourth embodiment, the case where the shutter 151 divided into the three shutter pieces 151a, 151b and 151c is used has been described. However, the present invention is not limited to this, and various division numbers can be used. Can be applied. In this case, as the number of divisions increases, it becomes possible to cope with various application patterns to be applied.

(Fifth embodiment)
FIG. 14 is a perspective view showing an ink jet head unit used in the ink jet coating apparatus according to the fifth embodiment of the present invention. The ink jet coating apparatus according to the fifth embodiment includes a plurality of in addition to the shutter 51 that covers all of the plurality of nozzles of the nozzle surface 48, as compared with the ink jet head unit according to the first embodiment described above with reference to FIG. The only difference is that the shutter 251 having the discharge window portion 251a is used in combination in a region corresponding to some of the nozzle discharge ports 50. Accordingly, in FIG. 14, the same reference numerals are given to corresponding parts to those in FIG. 4, and a duplicate description thereof is omitted here. In FIG. 14, the opening / closing mechanism for opening and closing the shutters 51 and 251 and the cleaning unit 60 (FIG. 4) are omitted. In the shutters 51 and 251, the opening / closing mechanisms (guide members 52 and 53, the motor 55, the pinion gear 57, and the rack 58) described above with reference to FIG. 4 are provided and individually opened and closed by the control unit.

  That is, as shown in FIG. 14, in the shutter 251 of the ink jet coating apparatus according to the fifth embodiment, for example, positions facing the three adjacent nozzle discharge ports 50a, 50b and 50c in a state where the shutter 251 is closed. When the ejection window portion 251a is formed in the nozzle and ink is ejected from the nozzle ejection ports 50a, 50b and 50c, the shutter 251 is closed. Thereby, nozzle discharge ports other than the nozzle discharge ports 50a, 50b and 50c to be used are covered with the shutter 251, and it is possible to prevent these nozzles from drying. Further, when the discharge from all the nozzle discharge ports 50 is stopped, the shutter 251 having the discharge window portion 251a is opened and the shutter 51 having no discharge window portion is closed, so that all of the nozzle discharge ports 50 are closed. Drying can be prevented.

  In the fifth embodiment, the case where the shutter 251 in which the discharge window portion 251a is formed at the position corresponding to the three nozzle discharge ports 50a, 50b and 50c is used is described. However, the present invention is not limited to this. The discharge window portion may be formed at a position corresponding to one or two or more various nozzles. In this case, the number of discharge window portions 251a is not limited to one, and a plurality of discharge window portions 251a may be formed.

  In the fifth embodiment, the case where the shutter 251 having the discharge window portion 251a and the shutter 51 not having the discharge window portion 251a are used in combination is described, but the present invention is not limited to this. You may make it use only the shutter 251 which has the discharge window part 251a. In this way, when the nozzles that are always used and the nozzles that are used as necessary coexist, the discharge window portion 251a is formed at a position corresponding to the nozzle that is always used, and is used as necessary. By closing the shutter 251 when the nozzles are not used, drying of these nozzles can be suppressed.

(Other embodiments)
The present invention is not limited to the above-described embodiment. For example, in the first to fifth embodiments described above, the case where the frame-shaped frame cover 49 that covers the entire periphery of the nozzle surface 48 is provided has been described. However, the present invention is not limited to this, and the frame The cover 49 may have a shape in which a part of the frame shape is cut out.

  In the inkjet coating apparatus 1 according to the first to fifth embodiments described above, the shutters 51, 151, 251 and the nozzles are disposed by interposing the frame cover 49 between the shutters 51, 151, 251 and the nozzle surface 48. Although the case where the contact with the surface 48 is prevented has been described, the present invention is not limited to this, and instead of the frame cover 49, for example, the guide members 52, 53 are replaced with the upper surface side and the lower surface of the shutters 51, 151, 251. It is possible to prevent contact between the shutters 51, 151, and 251 and the nozzle surface 48 by positioning the shutter 51 with this guide member. In this case, the periphery of the gap space formed between the shutters 51, 151, 251 and the nozzle surface 48 is not covered by the frame cover 49, but between the shutters 51, 151, 251 and the nozzle surface 48. Since the gap is suppressed to such an extent that the solvent atmosphere can be maintained, drying of the nozzle discharge port 50 can be sufficiently prevented in practice.

  In the inkjet coating apparatus 1 according to the first to fifth embodiments described above, the shutter 51, 151 is rotated by the rotational force of the motor 55 via the pinion gear 57 and the rack 58 as the opening / closing mechanism of the shutters 51, 151, 251. However, the present invention is not limited to this. For example, a part of the belt that is rotatably spanned over the movement range of the shutters 51, 151, and 251 is used as the shutter 51, Various other driving mechanisms can be applied as the driving mechanism, such as opening and closing the shutters 51, 151, and 251 by fixing them to 151 and 251 and rotating them.

  Further, in the ink jet coating apparatus 1 of the first to fifth embodiments described above, the case where the motor 55 is used as the drive source of the shutters 51, 151, and 251 has been described. Various other types of drive sources for the shutters 51, 151, and 251 can be applied, such as opening and closing the shutters 51, 151, and 251 via a link mechanism using the drive source as a drive source.

  In the first to fifth embodiments described above, the case where the inkjet head 42 is provided with opening / closing mechanisms such as the motor 55 and the guide members 52 and 53 that are the driving sources of the shutters 51, 151, and 251 has been described. The present invention is not limited to this, and for example, it may be supported by another member constituting the inkjet head unit 40.

  In the first to fifth embodiments described above, the shutters 51, 151, and 251 are made of glass plates and the frame cover 49 is made of a resin material. However, the present invention is limited to this. For example, the shutters 51, 151, 251 and the frame cover 49 may be made of various materials such as resin materials.

  In the first to fifth embodiments described above, the cleaning unit 60 that removes foreign matter using paper or cloth is used as a removing unit that removes foreign matter such as residual ink adhering to the upper surfaces of the shutters 51, 151, and 251. However, the present invention is not limited to this. For example, when the shutters 51, 151, and 251 are open, foreign matter is ejected by jetting air or solvent onto the upper surfaces of the shutters 51, 151, and 251. You may make it blow off.

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 fragmentary sectional view which shows the inkjet head of the inkjet coating apparatus of FIG. It is a partial side view which shows the inkjet head of the inkjet coating apparatus of FIG. It is a top view which shows the inkjet head of the inkjet coating apparatus of FIG. It is a fragmentary sectional view which shows the inkjet head of the inkjet coating apparatus of FIG. It is a side view with which it uses for description of the immersion process to the solvent tank of the inkjet head of the inkjet coating device of FIG. It is a side view with which it uses for description of the immersion process to the solvent tank of the inkjet head of the inkjet coating device of FIG. It is a side view with which it uses for description of the immersion process to the solvent tank of the inkjet head of the inkjet coating device of FIG. It is a fragmentary sectional view which shows the inkjet head of the inkjet coating apparatus which concerns on the 2nd Embodiment of this invention. It is a fragmentary sectional view which shows the inkjet head of the inkjet coating apparatus which concerns on the 3rd Embodiment of this invention. It is a perspective view which shows the inkjet head of the inkjet coating apparatus which concerns on the 4th Embodiment of this invention. It is a perspective view which shows the inkjet head of the inkjet coating apparatus which concerns on the 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inkjet coating device, 2 ... Stand, 3 ... Ink application box, 4 ... Ink supply box, 30 ... Substrate, 40 ... Inkjet head unit, 42 ... Inkjet head, 48 ... Nozzle surface, 49 ... Frame cover, 50 ... Nozzle , 51, 151, 251 ... shutter, 52, 53 ... guide member, 55 ... motor, 57 ... pinion gear, 58 ... rack.

Claims (11)

An ink jet head having a nozzle outlet that is an opening for ejecting droplets;
In the vicinity of the nozzle discharge port, a shutter provided to be able to advance and retreat so as to cover the nozzle discharge port;
A support mechanism for moving the shutter with a gap from the opening end surface of the nozzle discharge port between a position covering the nozzle discharge port and a position retracted from the covering position;
An inkjet coating apparatus comprising: The inkjet coating apparatus according to claim 1, wherein the support mechanism moves the shutter along the opening end surface. The distance between the position covering the nozzle discharge port of the shutter supported by the support mechanism and the opening end surface of the nozzle discharge port is set to be equal to or less than the maximum size for maintaining the solvent atmosphere of the nozzle discharge port. The inkjet coating apparatus according to claim 1. A solvent tank in which the solvent of the droplets is stored;
A moving mechanism for relatively moving the inkjet head and the solvent tank;
The inkjet coating apparatus according to claim 1, wherein the inkjet head in a state where the shutter is in a position covering the nozzle discharge port is immersed in a solvent stored in the solvent tank. The inkjet coating apparatus according to claim 1, further comprising: an ejection mechanism that ejects a solvent of the droplets to the inkjet head in a state where the shutter covers the nozzle discharge port. The inkjet coating apparatus according to claim 1, further comprising an air supply mechanism that supplies solvent gas of the droplets between a position of the shutter covering the nozzle discharge port and an opening end surface of the nozzle discharge port. . The inkjet coating apparatus according to claim 1, further comprising a suction mechanism that sucks a gap between a position of the shutter covering the nozzle discharge port and an opening end surface of the nozzle discharge port. In the inkjet head, a plurality of nozzle discharge ports are arranged,
The inkjet coating apparatus according to claim 1, wherein the shutter is divided into a plurality according to positions of the plurality of nozzle discharge ports arranged in the array. In the inkjet head, a plurality of nozzle discharge ports are arranged,
2. The inkjet coating according to claim 1, wherein the shutter includes a discharge window portion formed according to a position of one or two or more nozzle discharge ports among the plurality of arranged nozzle discharge ports. apparatus. In the inkjet head, a plurality of nozzle discharge ports are arranged,
The first shutter covering all of the plurality of arranged nozzle discharge ports;
A second shutter having an outer shape covering all of the plurality of nozzle discharge ports and having a discharge window portion formed corresponding to one or more positions of the plurality of nozzle discharge ports;
A support mechanism for moving the second shutter with respect to an opening end surface of the nozzle discharge port between a position where the second shutter covers the nozzle discharge port and a position where the second shutter is retracted from the cover position; ,
The inkjet coating apparatus according to claim 1, further comprising: In the vicinity of the nozzle discharge port, which is an opening for ejecting liquid droplets, a shutter provided so as to be able to advance and retract so as to cover the nozzle discharge port is moved to a position retracted from a position covering the nozzle discharge port, and the nozzle discharge A coating step of spraying the droplets from the outlet and applying the droplets to a coating target;
An application suspension step of stopping the ejection of the liquid droplets and moving the shutter to a position covering the nozzle discharge port while maintaining a gap with the opening end surface of the nozzle discharge port;
A coating method characterized by comprising:

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