JP2010145565A - Method of stirring liquid-like object in liquid droplet delivery head, and liquid droplet delivery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively stir a liquid-like object, even in a liquid-like object flow channel in a head. <P>SOLUTION: This device includes the liquid droplet delivery head 72 for delivering a liquid droplet of the liquid-like object from a nozzle opening 95 by driving a piezoelectric element 120. The device includes an opening and closing device 117 for opening and closing the nozzle opening, and a drive controller for driving the piezoelectric element under the condition where the nozzle opening is closed by the opening and closing device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid material stirring method for a droplet discharge head and a droplet discharge device.

In a droplet discharge head used in a recording apparatus such as a droplet discharge printer or a plotter, an ink solvent such as water evaporates at a nozzle opening, and the viscosity of the ink may be higher than necessary. If the viscosity of the ink becomes higher than necessary, problems such as a decrease in size (weight) of ink droplets (droplets) ejected from the nozzle openings may occur.
In particular, when using a liquid material that has the possibility of settling, such as a water-insoluble solvent-based ink, a dispersion ink, or a UV curable ink using a pigment as a coloring material, the nozzle opening is narrowed or blocked in some cases. It is also possible that

Therefore, Patent Document 1 and Patent Document 2 disclose a technique for maintaining the viscosity of the ink by stirring the ink at the nozzle opening by giving the meniscus at the nozzle opening a slight vibration that does not discharge the ink. ing.
JP 2000-085125 A JP 2001-270134 A

However, the following problems exist in the conventional technology as described above.
Since the ink stirring described above is performed at a pressure within a range where ink is not discharged, it cannot be said that sufficient stirring is performed.
In particular, in the case of using the liquid material with the possibility of settling described above, settling may occur not only in the nozzle opening but also in the ink flow path for guiding ink to the nozzle. It is extremely difficult to stir the ink in the ink flow path at a position separated from the nozzle opening.

  The present invention has been made in consideration of the above points, and provides a liquid material agitating method and a liquid droplet ejecting apparatus for a liquid droplet ejecting head capable of effectively agitating a liquid material even in a liquid material channel in the head. The purpose is to provide.

In order to achieve the above object, the present invention employs the following configuration.
A droplet discharge device of the present invention is a droplet discharge device including a droplet discharge head that discharges a liquid droplet from a nozzle opening by driving a piezoelectric element, the opening / closing device opening and closing the nozzle opening, And a drive control device that drives the piezoelectric element in a state where the nozzle opening is closed by an opening / closing device.
Therefore, in the droplet discharge device of the present invention, the nozzle opening is closed, and even if the drive of the piezoelectric element is increased, liquid droplets are not discharged from the nozzle opening. For this reason, in the present invention, it is possible to drive the piezoelectric element with a large force (vibration) rather than a slight vibration that does not eject a droplet from the nozzle opening. For this reason, the liquid material in the liquid droplet ejection head pressurized by the driving of the piezoelectric element is blocked from the nozzle opening by a much larger amount than the conventional flow amount due to fine vibration because the nozzle opening is closed. The flow path of the liquid material flows backward toward the liquid material supply side (the direction opposite to the direction toward the nozzle opening). When the driving of the piezoelectric element is stopped or when the piezoelectric element is driven in the reverse direction, the liquid in the droplet discharge head flows in the direction toward the nozzle opening by reversing the flow direction. Therefore, by controlling the driving of the piezoelectric element, the liquid material moves back and forth in the flow path, and efficient stirring can be performed.

The liquid droplet ejection head preferably has a flow path forming portion that forms a flow path that guides the liquid material to the nozzle opening, and a configuration that displaces the flow path forming portion by driving the piezoelectric element is also preferable. Can be adopted.
As a result, in the present invention, pressure (positive pressure or negative pressure) is applied to the liquid material filled in the flow path due to the displacement of the flow path forming portion, so that the liquid material is moved in the direction, amount, and speed according to this pressure. Can be moved and stirred.

The piezoelectric element may be provided for each of the plurality of nozzle openings, and the drive control device may preferably employ a configuration in which the plurality of piezoelectric elements are driven in synchronization.
Thereby, in this invention, it becomes possible to stir the liquid body of a some flow path at once, and can improve work efficiency.

The droplet discharge head includes a plurality of flow paths that are provided for each of a plurality of nozzle openings and guide the liquid material to the nozzle openings, and a liquid reservoir that is connected to each of the plurality of flow paths and stores the liquid material. It is also possible to suitably employ a configuration having
Thus, in the present invention, when pressurized in a plurality of flow paths, the liquid material flows from each flow path toward the liquid reservoir, and conversely, the pressure is reduced (released from pressure) in the plurality of flow paths. In this case, the liquid material flows from the liquid reservoir toward each flow path. Therefore, in the present invention, by controlling the driving of the piezoelectric element, the liquid material reciprocates between each flow path and the liquid reservoir, and the liquid material in each flow path and the liquid reservoir is Efficient stirring can be performed.

The liquid material agitation method for a liquid droplet ejection head according to the present invention is a liquid material agitation method for a liquid droplet ejection head that ejects a liquid droplet from a nozzle opening by driving a piezoelectric element, and the nozzle opening is closed. And a step of driving the piezoelectric element in a state in which the nozzle opening is closed.
Therefore, in the liquid stirring method for a liquid droplet discharge head according to the present invention, the nozzle opening is closed, and liquid droplets are not discharged from the nozzle opening even when the drive of the piezoelectric element is increased. For this reason, in the present invention, it is possible to drive the piezoelectric element with a large force (vibration) rather than a slight vibration that does not eject a droplet from the nozzle opening. For this reason, the liquid material in the liquid droplet ejection head pressurized by the driving of the piezoelectric element is blocked from the nozzle opening by a much larger amount than the conventional flow amount due to fine vibration because the nozzle opening is closed. The flow path of the liquid material flows backward toward the liquid material supply side (the direction opposite to the direction toward the nozzle opening). When the driving of the piezoelectric element is stopped or when the piezoelectric element is driven in the reverse direction, the liquid in the droplet discharge head flows in the direction toward the nozzle opening by reversing the flow direction. Therefore, by controlling the driving of the piezoelectric element, the liquid material moves back and forth in the flow path, and efficient stirring can be performed.

In the present invention, it is also possible to suitably employ a configuration that includes a flow path forming portion that forms a flow path that guides the liquid material to the nozzle opening and that displaces the flow path forming portion by driving the piezoelectric element.
Thus, in the present invention, in the present invention, pressure (positive pressure or negative pressure) is applied to the liquid filled in the flow path due to the displacement of the flow path forming portion, and therefore the direction, amount, and speed corresponding to this pressure are applied. The liquid can be moved and stirred.

In the present invention, a configuration in which the piezoelectric element is provided for each of the plurality of nozzle openings and the plurality of piezoelectric elements are driven in synchronization can be suitably employed.
Thereby, in this invention, it becomes possible to stir the liquid body of a some flow path at once, and can improve work efficiency.

The droplet discharge head includes a plurality of flow paths that are provided for each of a plurality of nozzle openings and guide the liquid material to the nozzle openings, and a liquid reservoir that is connected to each of the plurality of flow paths and stores the liquid material. It is also possible to suitably employ a configuration having
Thus, in the present invention, when pressurized in a plurality of flow paths, the liquid material flows from each flow path toward the liquid reservoir, and conversely, the pressure is reduced (released from pressure) in the plurality of flow paths. In this case, the liquid material flows from the liquid reservoir toward each flow path. Therefore, in the present invention, by controlling the driving of the piezoelectric element, the liquid material reciprocates between each flow path and the liquid reservoir, and the liquid material in each flow path and the liquid reservoir is Efficient stirring can be performed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a liquid material agitating method for a droplet discharge head and a droplet discharge apparatus according to the present invention will be described below with reference to FIGS.
In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

First, the droplet discharge device will be described.
As shown in FIGS. 1 to 3, the droplet discharge device 1 includes a large common frame 21 installed on the floor, a drawing device 22 widely placed on the entire area of the common frame 21, and the drawing device 22. The maintenance means 23 is provided, and the maintenance means 23 maintains and recovers the function of the functional liquid droplet ejection head 72 (droplet ejection head; see FIGS. 4 to 6), and the drawing device 22 places the work on the workpiece W. A drawing process for discharging the functional liquid is performed. Further, the droplet discharge device 1 incorporates a controller 24 (control unit 132, see FIG. 8) connected to the host computer 3 and controlling each means of the droplet discharge device 1.

  Moreover, the workpiece | work W (refer FIG. 1) introduce | transduced into the droplet discharge apparatus 1 is a transparent substrate comprised with quartz glass, a polyimide resin, etc. FIG.

  First, the drawing device 22 in the droplet discharge device 1 and the drawing processing by this will be described. The drawing device 22 is installed on the common platform 21 and a plurality of (for example, seven) carriage units 31 including a plurality of (for example, twelve) functional liquid droplet ejection heads 72 and a carriage 73 on which the drawing is performed. The X-axis table 32 for moving the workpiece W in the X-axis direction, and the seven carriage units 31 are individually connected to the Y-axis. A functional liquid supply means 34 including a Y-axis table 33 that is moved in the direction, and seven functional liquid supply units 101 that respectively supply the functional liquid to the functional liquid droplet ejection heads 72 mounted on the seven carriage units 31; Image recognition means 35 (see FIG. 8) for recognizing the workpiece W, the carriage unit 31 and the like is provided.

  A region where the movement trajectory of the workpiece W by the X-axis table 32 and the movement trajectory of the carriage unit 31 by the Y-axis table 33 intersect is a drawing area 41 for performing drawing processing. An area outside the X axis table 32 on the movement trajectory of the carriage unit 31 is a drawing standby area 42, and the maintenance means 23 is installed in the drawing standby area 42. On the other hand, the area on the near side of the X-axis table 32 is a work carry-in / out area 43 where the work W is carried into and out of the droplet discharge device 1.

  The X-axis table 32 sets the introduced work W, an X-axis air slider 52 that supports the set table 51 slidably in the X-axis direction, and extends in the X-axis direction. A pair of left and right X-axis linear motors 53, 53 that move the workpiece W in the X-axis direction via the X-axis, and a pair of X-axis guide rails that are arranged in parallel to the X-axis linear motor 53 and guide the movement of the X-axis air slider 52 54, and an X-axis linear scale (not shown) for grasping the position of the set table 51. When the pair of X-axis linear motors 53 and 53 are driven, the X-axis air slider 52 is moved in the X-axis direction while using the pair of X-axis guide rails 54 and 54 as a guide, and the workpiece set on the set table 51 W moves in the X-axis direction.

  The set table 51 is disposed on the X-axis air slider 52 connected to the suction table 56 for directly sucking and setting the workpiece W, the rotating unit 58 connected to the lower part of the suction table 56, and the lower part of the rotating unit 58. It has a fixed portion 59 and has a workpiece θ axis table 57 that finely adjusts (θ correction) the θ position of the workpiece W via the suction table 56.

The suction table 56 is formed in a substantially square shape in plan view, and the length of one side thereof is set according to the length of the long side of the workpiece W having the maximum size, and the workpiece W is placed vertically (the long side of the workpiece W). Can be set in any direction, either in parallel with the X-axis direction) or horizontally (with the long side of the workpiece W parallel to the Y-axis direction). In addition, the workpieces W of any size are set center-aligned.
Note that the periodic flushing box 116 and the nozzle surface closing device (opening / closing device) of the maintenance means 23 are adjacent to the drawing area 41 side (right side in FIG. 3) of the suction table 56 on the fixed portion 59 of the work θ-axis table 57. ) 117 is installed.

  On the other hand, the Y-axis table 33 is supported on a pair of front and rear support stands 66, 66 extending in the Y-axis direction, spans between the drawing area 41 and the drawing standby area 42, and includes seven carriage units 31. These are moved individually between the drawing area 41 and the drawing standby area 42. The Y-axis table 33 includes seven bridge plates 61 that respectively suspend the seven carriage units 31 and seven sets that support the seven bridge plates 61 with both ends so that the seven bridge plates 61 are aligned in the Y-axis direction. A Y-axis slide table 62, a pair of front and rear Y-axis linear motors 63, 63 extending in the Y-axis direction and moving each bridge plate 61 in the Y-axis direction via each set of Y-axis slide tables 62; Two Y-axis guide rails 64 that extend in the axial direction and guide the movement of the seven bridge plates 61 (four in total) and a Y-axis linear scale that detects the movement position of each carriage unit 31 ( (Not shown).

When the pair of Y-axis linear motors 63, 63 are driven, the seven sets of Y-axis slide tables 62 can be moved independently, and the seven carriage units 31 can be individually moved in the Y-axis direction. According to this, each movement with respect to the seven carriage units 31 can be performed with a simple structure and high accuracy. Of course, it is also possible to move the seven carriage units 31 together in the Y-axis direction by simultaneously moving the seven sets of Y-axis slide tables 62 in the Y-axis direction.
In this embodiment, seven carriage units 31 are mounted side by side on a single Y-axis table 33. However, a plurality of Y-axis tables 33 are provided, and the seven carriage units 31 are divided and mounted. May be.

Furthermore, on the bridge plate 61 supported by each pair of Y-axis slide tables 62, a head electrical unit 97 for driving the 12 functional liquid droplet ejection heads 72 mounted on the corresponding carriage units 31 is provided. The seven head electrical units 97 are arranged in a staggered manner so as not to interfere with each other (noise prevention). In addition, brackets 67 are fixed outwardly on the front and rear side surfaces of the pair of front and rear support stands 66 and 66, and a Y-axis accommodation box 68 is supported on each bracket 67. The two Y-axis housing boxes 68 have four Y-axis cable carriers 69 (cable bear: registered trademark) corresponding to the staggered arrangement of the seven head electrical units 97, four and three. Each Y-axis cable carrier 69 is configured such that a flexible flat cable connected to the head electrical unit 97 can follow the movement of each carriage unit 31.
Further, the tank units (not shown) of the seven functional liquid supply units 101 are arranged in a staggered manner so as to face each of the head electrical units 66.

  As shown in FIGS. 1 and 4, the seven carriage units 31 are suspended from the seven bridge plates 61 of the Y-axis table 33 and are arranged in the Y-axis direction. The head unit 71 is composed of individual functional liquid droplet ejection heads 72 and a carriage 73 on which the head unit 71 and a valve unit 104 (described later) of the functional liquid supply unit 101 are mounted. The seven carriage units 31 are arranged in order from the drawing area 41 side to the drawing standby area 42 side (from the left side to the right side in FIG. 4), in order, the first carriage unit 31a, the second carriage unit 31b,. The seventh carriage unit 31g.

  As shown in FIGS. 3 and 4, each carriage 73 includes a support plate 76 having a substantially parallelogram in plan view for positioning and fixing the head unit 71 and the valve unit 104, a carriage body 77 for holding the support plate 76, a carriage A main body 77 is suspended and connected to an upper portion of the carriage main body 77, and a head θ-axis table 78 for finely adjusting (θ-axis correction) the θ position of the head unit 71 via the carriage main body 77, and the head θ-axis table 78. And a head Z-axis table 79 that finely adjusts the Z position of the head unit 71 (Z-axis correction) via a head θ-axis table 78 and a carriage body 77. Although not shown, each support plate 76 serves as a reference for positioning (position recognition) each carriage unit 31 (head unit 71) in the X-axis, Y-axis, and θ-axis directions on the premise of image recognition. A pair of reference pins is provided.

  The support plate 76 is made of a thick plate having a substantially parallelogram shape in a plan view made of stainless steel or the like. The support plate 76 positions twelve functional liquid droplet ejection heads 72 and each functional liquid droplet by a head holding member (not shown). Twelve mounting openings (not shown) for fixing the ejection head 72 from the back side are formed. The support plate 76 is detachably supported by the carriage body 77, and the head unit 71 is mounted on the carriage 73 via the support plate 76 together with the valve unit 104.

  As shown in FIG. 5, the functional liquid droplet ejection head 72 has a so-called double structure, a functional liquid introduction part 81 having two connection needles 82, and a dual head substrate that is continuous with the functional liquid introduction part 81. 83, and a head main body 84 which is connected to the lower side (upper side in the figure) of the functional liquid introduction portion 81 and in which an in-head flow path filled with the functional liquid is formed. The connection needle 82 is connected to a functional liquid tank (not shown) via a pressure adjustment valve 105 (see FIG. 4) described later, and supplies the functional liquid to the flow path in the head of the functional liquid droplet ejection head 72. The head main body 84 includes a cavity 91 formed of a piezo element and the like, and a nozzle plate 92 having a nozzle surface 93 in which two nozzle rows 94 and 94 are formed in parallel to each other.

Each nozzle row 94 has a length of, for example, 1 inch (approximately 25.4 mm), and each nozzle row 94 includes 180 nozzles 95 arranged at an equal pitch (approximately 140 μm).
Further, due to the structure of the flow path in the head, the discharge amount from the nozzles 95 located at both ends becomes larger than the discharge amount from the nozzle 95 located at the center portion, so that each of the ten nozzles at both ends. 95 is a non-ejection nozzle, and 160 nozzles 95 in the center are used as ejection nozzles, so that the functional liquid is ejected only from the ejection nozzle and the functional liquid is not ejected from the non-ejection nozzle.

Next, the nozzle plate 92 and the cavity 91 in the functional liquid droplet ejection head 72 will be described.
FIG. 6A is a structural explanatory view of the functional liquid droplet ejection head 72, and FIG. 6B is a front sectional view. In FIG. 6, the functional liquid droplet ejection head 72 is shown upside down with respect to FIG.

The functional liquid droplet ejection head 72 compresses the liquid chamber with, for example, a piezo element and ejects the liquid with the pressure wave, and has a plurality of nozzles 95 arranged in a plurality of rows as described above. An example of the structure of the functional liquid droplet ejection head 72 will be described. As shown in FIG. 6A, the functional liquid droplet ejection head 72 includes, for example, a stainless steel nozzle plate 92 and a vibration plate 123. It is joined via a partition member (reservoir plate) 124. A plurality of spaces 125 and a liquid reservoir 126 are formed by the partition member 124 between the nozzle plate 92 and the diaphragm 123 as a flow path forming unit. Each space 125 and the liquid reservoir 126 are filled with ink (liquid material), and each space 125 and the liquid reservoir 126 are in communication (connected) via the supply port 127. . That is, the space 125 and the supply port 127 form a flow path 128 for guiding the ink filled in the liquid reservoir 126 to the nozzle 95.
The nozzle plate 92 is formed with nozzles (nozzle openings) 95 for ejecting ink from the space 125. On the other hand, a hole 129 for supplying ink to the liquid reservoir 126 is formed in the vibration plate 123.

  Also, a piezoelectric element (piezo element) 120 is bonded to the surface of the diaphragm 123 opposite to the surface facing the space 125, as shown in FIG. 6B. The piezoelectric element 120 is configured such that a piezoelectric material is sandwiched between a pair of electrodes 130, and is configured such that the piezoelectric material contracts when the pair of electrodes 130 are energized, and is provided for each nozzle 95. The diaphragm 123 to which the piezoelectric element 120 is bonded in such a configuration is bent together with the piezoelectric element 120 at the same time so that the volume of the space 125 is increased. It is going to increase. Therefore, ink corresponding to the increased volume in the space 125 flows from the liquid reservoir 126 through the supply port 127. Further, when the energization to the piezoelectric element 120 is released from such a state, both the piezoelectric element 120 and the diaphragm 123 return to their original shapes. Therefore, since the space 125 also returns to the original volume, the pressure of the ink inside the space 125 rises, and the ink droplet L is ejected from the nozzle 95 toward the substrate.

  That is, the head substrate 83 described above is provided with two connectors 96, 96, and each connector 96 is connected to the above-described head electrical unit 97 (head driver 141, see FIG. 8) via a flexible flat cable. It is connected to the. When a driving waveform is applied from the controller 24 to the cavity 91 (electrode 130) via the head electrical unit 97, functional droplets are ejected from each nozzle 95 by the pumping action of the cavity 91 due to the bending of the diaphragm 123. Is done. Therefore, the droplet discharge amount and the discharge timing are independently controlled for each nozzle 95 by controlling the magnitude of the drive waveform applied to the cavity 91 (the magnitude of the applied voltage value) and the period.

  In the present embodiment, the functional liquid droplets in the drawing area 41 are moved relative to the workpiece W while the working unit group 36 including at least one carriage unit 31 out of the seven carriage units 31 is moved in the X-axis direction. The drawing is performed by discharging the functional liquid from the discharge head 72 onto the workpiece W.

  The droplet discharge method of the functional droplet discharge head 72 may be a method other than the piezo jet type using the piezoelectric element 120. For example, a method using an electrothermal transducer as an energy generating element is adopted. May be.

  Each of the functional liquid supply units 101 of the functional liquid supply means 34 includes a tank unit including 12 functional liquid tanks that store the functional liquid, and 12 units that adjust the hydraulic head pressure between the functional liquid tank and the functional liquid droplet ejection head 72. Valve unit 104 composed of the pressure adjusting valve 105, twelve tank-side liquid supply tubes (not shown) for connecting twelve functional liquid tanks and twelve pressure adjusting valves 105, and twelve pressure adjustments. The valve 105 and twelve functional liquid droplet ejection heads 72 (each of the two connecting needles 82) have 24 head side liquid supply tubes (not shown) respectively connected via branch joints (not shown). is doing.

  The two image recognition means 35 are disposed so as to face both the front and rear sides of the workpiece carry-in / out area 43, and two units recognize each of two workpiece alignment marks (not shown) formed on both long side portions of the workpiece W, respectively. The head recognition camera 107 (see FIG. 8) connected to the X-axis air slider 52 of the X-axis table 32 and the image recognition of the two reference pins of each carriage 73 (support plate 76). And a functional liquid droplet (dot) that is mounted on the Y-axis table 33 so as to be movable in the Y-axis direction by a camera moving mechanism (not shown) attached to the Y-axis table 33 and discharged onto the workpiece W or the like from above. It has two dot recognition cameras 108 (see FIG. 8) that capture and recognize images. Based on the image recognition results of these various cameras, the above-described position correction of the workpiece W and the head unit 71 is performed.

  Here, with reference to FIG. 1 thru | or FIG. 3, the discharge operation | movement to the workpiece | work W by the drawing apparatus 22, ie, drawing operation, is demonstrated easily. First, as a preparation before discharging the functional liquid, the workpiece W is set on the suction table 56 by the workpiece loading / unloading device 2, and the position correction of the workpiece W is performed by the workpiece θ-axis table 57 in the θ-axis direction correction. And position data correction of the workpiece W in the X-axis direction and the Y-axis direction. Before and after, the active unit group 36 that moves to the drawing area 41 and the drawing standby unit group 37 that moves to the drawing standby area 42 are sorted (details will be described later). Further, the position correction of each head unit 71 of the working unit group 36 moved to the drawing area 41 includes the position correction in the θ-axis direction by the head θ-axis table 78, the position correction in the Y-axis direction by the Y-axis table 33, and the head unit. 71 is performed by correcting the position data in the X-axis direction.

  After the position correction of the workpiece W and the head unit 71 is performed, the drawing apparatus 22 moves the workpiece W in the X-axis direction by the X-axis table 32 while being controlled by the controller 24 (control unit 132). In synchronization with this, the functional liquid droplet ejection head 72 of the operation unit group 36 is selectively driven to eject the functional liquid onto the workpiece W. Subsequently, the functional liquid is discharged again to the workpiece W while moving the workpiece W backward. In this way, drawing on the workpiece W is performed by repeating the reciprocating movement of the workpiece W in the X-axis direction and the driving of the functional liquid droplet ejection head 72 a plurality of times. That is, the functional liquid is discharged onto the work W from the functional liquid droplet ejection head 72 of the operating unit group 36 while moving the operating unit group 36 relative to the work W facing the drawing area 41 in the X-axis direction. Drawing processing is performed.

  In the drawing process, the functional liquid may be discharged only when the workpiece W moves forward. Alternatively, the work W may be fixed and the operating unit group 36 may be moved in the X-axis direction. Furthermore, in the present embodiment, as described above, the drawing target width of the work W corresponds to the length of the partial drawing line group of the operating unit group 36, but the drawing target width of the work W corresponds to the operating unit group 36. The length may be longer than the length of the partial drawing line group. In this case, the functional liquid droplet ejection head 72 is driven while the operation unit group 36 is reciprocated with respect to the workpiece W to perform ejection scanning (main scanning). Then, the working unit group 36 is moved in the Y-axis direction by the length of the partial drawing line group by the Y-axis table 33 (sub-scanning), and the main scanning for the workpiece W is performed again. Then, the main scanning and the sub scanning are repeated several times to discharge the droplets from the end to the end of the workpiece W.

  Next, with reference to FIG. 2 and FIG. 7, the maintenance means 23 in the droplet discharge device 1 and the function maintenance / recovery processing of the functional droplet discharge head 72 by this will be described. The maintenance means 23 stores the functional liquid droplet ejection head 72 in a state where the ejection function is maintained, and maintains / recovers the ejection function. The maintenance means 23 sucks the functional liquid droplet ejection head 72 and forcibly discharges the functional liquid from the functional liquid droplet ejection head 72, and the functional liquid droplet ejection head 72 that is contaminated with the functional liquid. A wiping unit 113 for wiping the nozzle surface 93, seven divided suction units 112 (described later) of the suction unit 111, and eight unit lifting mechanisms 115 that individually support the wiping unit 113 so as to be lifted and lowered individually. The unit lifting / lowering means 114 is supported on the angle base 118 and disposed in the drawing standby area 42. Further, the maintenance means 23 includes a regular flushing box 116 disposed on the workpiece θ-axis table 57, a nozzle surface closing device 117, and a pair of pre-discharge flushing boxes disposed on both front and rear sides of the set table 51. (Not shown).

  The suction unit 111 has seven divided suction units 112 arranged in the Y-axis direction corresponding to the seven carriage units 31. Each of the divided suction units 112 faces the carriage unit 31 from below and includes twelve caps 121 and twelve caps 121 that are hermetically sealed to the nozzle surfaces 93 of the twelve functional liquid droplet ejection heads 72. And a ejector (not shown) that applies a suction force to the functional liquid droplet ejection head 72 via the sealed cap 121.

  The twelve caps 121 are arranged on the cap support member 122 so as to correspond to the twelve functional liquid droplet ejection heads 72 mounted on each carriage 73. Therefore, in the entire suction unit 111, 12 × 7 caps 121 are arranged following the arrangement pattern of the all-function droplet discharge heads 72 of the seven carriage units 31. Each corresponding cap 121 can be sealed at a time. Further, by driving the ejector with the cap 121 sealed to the nozzle surface 93, the functional liquid sucked out from the nozzle 95 is removed to remove the functional liquid thickened in the functional liquid droplet ejection head 72. Can do.

  Therefore, the suction unit 111 hermetically seals the functional liquid droplet ejection head 72 with each cap 121, so that the functional liquid of the nozzle 95 of the functional liquid droplet ejection head 72 is dried without using a complicated mechanism. The functional liquid droplet ejection head 72 is stored in a function maintaining state, and the functional liquid with increased viscosity is discharged by being sucked from the nozzles 95 of the functional liquid droplet ejection head 72 in an airtight state by the caps 121. be able to.

  The wiping unit 113 is arranged on the drawing area 41 side of the drawing standby area 42, that is, between the drawing area 41 and the suction unit 111, and the functional liquid adheres and becomes dirty due to the suction of the functional liquid droplet ejection head 72. The nozzle surface 93 is wiped with a wiping sheet 123 impregnated with a cleaning liquid. With such an arrangement, the wiping unit 113 can finish the suction by the suction unit 111 and sequentially face the carriage unit 31 that individually moves to the drawing area 41, and performs the wiping process on the functional liquid droplet ejection head 72. Be able to. Then, the ejection function of the functional liquid droplet ejection head 72 in which nozzle clogging has occurred can be recovered by the above-described suction processing and wiping to wipe off the functional liquid adhering to the nozzle surface 93 by the suction processing.

  As shown in FIG. 3, the periodic flushing box 116 is for receiving flushing that is performed when drawing on the workpiece W is temporarily stopped, and is provided on the workpiece θ-axis table 57, When the set table 51 faces the workpiece carry-in / out area 43 for replacement, the regular flushing box 116 faces the drawing area 41 and receives the flushing from the functional liquid droplet ejection head 72.

Although not shown, the pair of pre-discharge flushing boxes is for receiving pre-discharge flushing performed immediately before discharging the functional liquid onto the workpiece W, and is disposed so as to sandwich the set table 51 in the X-axis direction. . Thereby, it is possible to receive the flushing performed immediately before the ejection driving of the functional liquid droplet ejection head 72 accompanying the reciprocation of the workpiece W.
The regular flushing box 116 and the pair of pre-discharge flushing boxes are each formed in a rectangular box shape in plan view, and an absorbent material (not shown) for absorbing the functional liquid is laid on the bottom thereof. In addition, since the long side (Y-axis direction) of each flushing box is formed corresponding to the length of the maximum width drawing line Lm, the operation unit group 36 is configured by all the carriage units 31. In addition, flushing from the functional liquid droplet ejection head 72 can be received.

As shown in FIG. 3, the nozzle surface closing device 117 is provided on the workpiece θ axis table 57, for example, on the + X side of the periodic flushing box 116, and when the set table 51 faces the workpiece loading / unloading area 43, When the surface closing device 117 faces the drawing area 41 and is lifted by the lifting / lowering device 118, the nozzle opening 95 is closed by contacting the nozzle surface 93 of the functional liquid droplet ejection head 72, and when the surface closing device 117 is lowered by the lifting / lowering device 118 The nozzle opening 95 is opened away from the surface 93.
As a material for the nozzle surface closing device 117, strength and hardness capable of reliably preventing droplet discharge from the nozzle opening 95 without damaging the functional droplet discharge head 72 even when contacting the nozzle surface 93. For example, a resin plate or a rubber plate can be used.

  Next, with reference to FIG. 8, the control system of the entire droplet discharge device 1 will be briefly described. The control system of the droplet discharge apparatus 1 basically includes a host computer 3 and a drive unit 131 having various drivers for driving the functional droplet discharge head 72, the X-axis table 32, the Y-axis table 33, the maintenance means 23, and the like. And a control unit 132 (controller 24) that comprehensively controls the entire droplet discharge device 1 including the drive unit 131.

The host computer 3 is configured by connecting a computer 17 connected to a controller 24 to a keyboard 17 and a display 18 for displaying an image of an input result or the like by the keyboard 17.
The drive unit 131 includes a head driver 141 that controls the ejection of the functional liquid droplet ejection head 72, a moving driver 142 that controls the motors of the X-axis table 32 and the Y-axis table 33, and a suction unit of the maintenance unit 23. 111, a wiping unit 113, and a maintenance driver 143 that drives and controls the unit lifting mechanism 115.

  The control unit 132 includes a CPU 151, a ROM 152, a RAM 153, and a P-CON 154, which are connected to each other via a bus 155. The ROM 152 has a control program area for storing a control program to be processed by the CPU 151, and a control data area for storing control data for performing a drawing operation and image recognition.

  The RAM 153 includes, in addition to various register groups, a drawing data storage unit that stores drawing data for discharging functional liquid to the workpiece W, a position data storage unit that stores position data of the workpiece W and the functional liquid droplet ejection head 72, It has various storage units such as a setting storage unit that stores various settings (such as settings of an operation unit group 36 and a drawing standby unit group 37 described later) input from the keyboard 17 by an operator, and performs various operations for control processing. Used as a region.

  In addition to various drivers of the drive unit 131, various cameras of the image recognition means 35 are connected to the P-CON 154, and a logic circuit is constructed to supplement the functions of the CPU 151 and handle interface signals with peripheral circuits. Built in. For this reason, the P-CON 154 receives various commands and the like from the host computer 3 as they are or processes them and imports them into the bus 155. Or it processes and outputs to the drive part 131. FIG.

  The CPU 151 inputs various detection signals, various commands, various data, etc. via the P-CON 154 according to the control program in the ROM 152, processes various data, etc. in the RAM 153, and then drives via the P-CON 154. The entire droplet discharge device 1 is controlled by outputting various control signals to the unit 131 and the like. For example, the CPU 151 controls the functional droplet discharge head 72, the X-axis table 32, and the Y-axis table 33 to perform drawing on the workpiece W under predetermined droplet discharge conditions and predetermined movement conditions.

Next, a method of stirring the ink (liquid material) inside the functional droplet discharge head 72 in the droplet discharge apparatus 1 will be described with reference to FIG.
FIG. 9A is a cross-sectional view of the functional liquid droplet ejection head 72 in which the supply port 127 and the flow path 128 are filled with ink.
As shown in this figure, first, the lifting / lowering device 118 is driven to bring the nozzle surface closing device 117 into contact with the nozzle surface 93 of the functional liquid droplet ejection head 72 so that the nozzle surface 93a is flush with the nozzle surface 93a. The opening 95 is closed.

  Subsequently, the piezoelectric element 120 is driven (the electrode 130 is energized), and the diaphragm 123 is displaced toward the space 125 as shown in FIG. 9B, for example. Thereby, since the volume of the flow path 128 decreases, the pressure of the ink in the space 125 increases. At this time, since the nozzle opening 95 is closed by the nozzle surface closing device 117, the ink is not ejected from the nozzle opening 95 and is directed from the flow path 128 toward the liquid reservoir 126 as indicated by an arrow in the figure. To flow.

  Next, the piezoelectric element 120 is driven in the opposite direction, and the diaphragm 123 is displaced in a direction away from the space 125 as shown in FIG. As a result, the volume of the flow path 128 increases, and the ink pressure in the space 125 decreases. At this time, since the nozzle opening 95 is closed by the nozzle surface closing device 117, air does not flow from the nozzle opening 95 and the pressure drop of the ink is not released. Therefore, as the ink pressure in the space 125 decreases, the ink flows from the liquid reservoir 126 toward the flow path 128 as indicated by the arrows in the figure.

  Note that, instead of driving the piezoelectric element 120 in the reverse direction, the driving of the piezoelectric element 120 that displaces the diaphragm 123 toward the space 125 is stopped, and the diaphragm 123 is shown in FIG. You may just return to the state.

  Then, by sequentially reversing the driving direction of the piezoelectric element 120, the ink moves between the flow path 128 and the liquid reservoir 126 in the direction shown in FIG. 9B and the direction shown in FIG. 9C. Will flow back and forth. The ink is agitated by the reciprocal movement of the ink.

  In addition, when the plurality of nozzle openings 95 and the piezoelectric elements 120 provided for the respective channels 128 in the functional liquid droplet ejection head 72 are driven simultaneously in synchronization, the ink in the plurality of channels 128 flows to Since the fluid reciprocates between the path 128 and the liquid reservoir 126, the amount of reciprocation of the ink in the liquid reservoir 126 also increases, so that the ink in the liquid reservoir 126 is also agitated.

  After the ink agitation processing in the functional liquid droplet ejection head 72 is completed, the nozzle surface closing device 117 is lowered and separated from the nozzle surface 93 by driving the elevating device 118 to open the nozzle opening 95. By doing so, the above-described droplet discharge process can be executed.

  Thus, in this embodiment, since the piezoelectric element 120 is driven in a state where the nozzle opening 95 is closed, the driving of the piezoelectric element 120 is limited so that ink is not ejected from the nozzle opening 95 as in the prior art. The diaphragm 123 can be greatly displaced. For this reason, in this embodiment, it is possible to stir the ink in the flow path 128 with a large flow length, which is effective even in the flow path 128 that is farther away from the nozzle opening 95 that could not be sufficiently stirred conventionally. The ink can be agitated. Therefore, in this embodiment, even when using a water-insoluble solvent-based ink using a pigment as a coloring material, a dispersion-type ink, a UV-curable ink, or other ink that has the possibility of settling, the occurrence of settling is suppressed. In addition, it is possible to effectively avoid ink discharge defects caused by sedimentation and the like, and it is possible to manufacture a high-quality device.

  Further, in this embodiment, by driving the piezoelectric elements 120 provided for each of the plurality of nozzle openings 95 in synchronization, not only the flow path 128 but also the ink in the liquid reservoir 126 can be effectively stirred. This makes it possible to more effectively suppress ink discharge defects caused by sedimentation and the like.

[Color filter manufacturing method]
Next, an example of a color filter manufacturing method using the droplet discharge device 1 of the present embodiment will be described. FIG. 10 is an explanatory diagram of the color filter region 151 in the substrate S. FIG. The color filter manufacturing method using the droplet discharge device 1 can be applied when forming a plurality of color filter regions 151 in a matrix on the rectangular substrate S from the viewpoint of increasing productivity. . These color filter regions 151 can be used as individual color filters suitable for a liquid crystal display device by cutting the substrate S later. In each color filter region 151, as shown in FIG. 10, the R ink, the G ink, and the B ink are respectively formed in a predetermined pattern, in this example, a conventionally known stripe type. . In addition to the stripe type, the formation pattern may be a mosaic type, a delta type, or a square type.

  FIG. 11 is an explanatory diagram of a color filter manufacturing method. In order to form such a color filter region 151, first, a black matrix 152 is formed on one surface of the transparent substrate S as shown in FIG. When forming the black matrix 152, a non-light-transmitting resin (preferably a black resin) is applied to a predetermined thickness (for example, about 2 μm) by a method such as spin coating, and photolithography technology is used. Pattern. For the minimum display element surrounded by the black matrix 152, that is, the filter element 153, for example, the width in the X-axis direction is about 30 μm and the length in the Y-axis direction is about 100 μm. This black matrix has a sufficient height and functions as a partition wall during ink ejection.

  Next, as shown in FIG. 11B, ink droplets 154 (liquid material) containing a resin composition serving as an ink receiving layer are ejected from the droplet ejection head in the droplet ejection apparatus 1 of the present embodiment. This is landed on the substrate S. The amount of ink droplets 154 to be ejected is a sufficient amount in consideration of the ink volume reduction in the heating process. Next, the ink droplets are baked to form an ink receiving layer 160 as shown in FIG.

  Next, as shown in FIG. 11D, R ink droplets 154 </ b> R (liquid material) are ejected from the droplet ejection head 72 and landed on the substrate S. The amount of ink droplets 154 to be ejected is a sufficient amount in consideration of the ink volume reduction in the heating process. Next, the ink is temporarily baked to form an R colored layer 134R as shown in FIG. The above steps are repeated in the G colored layer forming apparatus and the B colored layer forming apparatus, and the G colored layer 134G and the B colored layer 134B are sequentially formed as shown in FIG. After all of the R colored layer 134R, the G colored layer 134G, and the B colored layer 134B are formed, these colored layers 134R, 134G, and 134B are baked together.

  Next, in order to flatten the substrate S and protect the colored layers 134R, 134G, and 134B, an overcoat film (protective film) that covers the colored layers 134R, 134G, and 134B and the black matrix 152 as shown in FIG. ) 156. In forming the overcoat film 156, a method such as a spin coating method, a roll coating method, or a ripping method may be employed, but the droplet discharge device 1 is used in the same manner as in the case of the colored layers 134R, 134G, and 134B. You can also.

[Liquid Crystal Device]
Next, an embodiment of a liquid crystal device (electro-optical device) including the color filter will be described. FIG. 12 is a side sectional view of a passive matrix liquid crystal device, and reference numeral 130 in FIG. 12 denotes a liquid crystal device. The liquid crystal device 130 is of a transmissive type, and a liquid crystal layer 133 made of STN (Super Twisted Nematic) liquid crystal or the like is sandwiched between a pair of glass substrates 131 and 132.

  The color filter 155 is formed on the inner surface of one glass substrate 131. The color filter 155 is configured by regularly arranging colored layers 134R, 134G, and 134B composed of R, G, and B colors. A black matrix 152 is formed between the dye layers 134R (134G, 134B). An overcoat film (protective film) 156 is formed on the color filter 155 and the black matrix 152 in order to eliminate the step formed by the color filter 155 and the black matrix 152 and to flatten the same. . A plurality of electrodes 137 are formed in a stripe shape on the overcoat film 156, and an alignment film 138 is further formed thereon.

  On the other glass substrate 132, a plurality of electrodes 139 are formed in stripes on the inner surface so as to be orthogonal to the electrodes 137 on the color filter 155 side, and an alignment film 140 is formed on these electrodes 139. Is formed. The colored layers 134R, 134G, and 134B of the color filter 155 are disposed at positions where the electrodes 139 and 137 intersect on the glass substrates 132, respectively. The electrodes 137 and 139 are formed of a transparent conductive material such as ITO (Indium Tin Oxide). Furthermore, polarizing plates (not shown) are provided on the outer surface sides of the glass substrate 132 and the color filter 155, respectively, and the space (cell gap) between the substrates 131 and 132 is kept constant between the glass substrates 131 and 132. For this purpose, a spacer 141 is provided. Further, a sealing material 142 for sealing the liquid crystal 133 is provided between the glass substrates 131 and 132.

  In the liquid crystal device 130 of the present embodiment, the color filter 155 manufactured using the droplet discharge device 1 is applied, so that a low-cost and high-quality color liquid crystal display device can be realized.

[Electronics]
Next, a specific example of an electronic apparatus provided with display means including the liquid crystal device will be described.
FIG. 13 is a perspective view showing an example of a liquid crystal television. In FIG. 13, reference numeral 500 denotes a liquid crystal television main body, and reference numeral 501 denotes a liquid crystal display unit including the liquid crystal device of the above embodiment. As described above, since the electronic apparatus illustrated in FIG. 13 includes the liquid crystal device of the above-described embodiment, an electronic apparatus having a color liquid crystal display that is inexpensive and excellent in display quality can be realized.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, the nozzle surface closing device 117 is provided on the work θ-axis table 57. However, the present invention is not limited to this, and for example, a carriage unit that moves integrally with the functional liquid droplet ejection head 72. 31 may be provided.
In this configuration, the ink agitation process can be executed regardless of the position of the functional liquid droplet ejection head 72, and the functional liquid droplet ejection head 72 is moved to a position where the nozzle surface closing device 117 is installed. The process becomes unnecessary, and the productivity can be greatly improved.

It is an external appearance perspective view of a droplet discharge device. It is a top view of a droplet discharge device. It is a side view of a droplet discharge device. It is explanatory drawing of a some carriage unit. It is an external appearance perspective view of a functional droplet discharge head. It is explanatory drawing of a droplet discharge head. It is an external appearance perspective view of a maintenance means. It is the block diagram explaining the control system of the droplet discharge apparatus. It is a figure for demonstrating the stirring process of an ink. It is explanatory drawing of the color filter area | region in a board | substrate. It is explanatory drawing of the manufacturing method of a color filter. It is side surface sectional drawing of a passive matrix type liquid crystal device. It is the perspective view which showed an example of the liquid crystal television.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Droplet discharge device, 24 ... Controller (drive control device), 72 ... Functional droplet discharge head (droplet discharge head), 117 ... Nozzle surface closing device (opening / closing device), 120 ... Piezoelectric element, 123 ... Vibration plate (Channel forming part), 126 ... liquid reservoir, 128 ... channel, L ... droplet

Claims (8)

A droplet discharge device including a droplet discharge head for discharging a liquid droplet from a nozzle opening by driving a piezoelectric element,
An opening and closing device for opening and closing the nozzle opening;
And a drive control device that drives the piezoelectric element in a state where the nozzle opening is closed by the opening / closing device. The droplet discharge device according to claim 1,
The droplet discharge head has a flow path forming portion that forms a flow path for guiding the liquid material to the nozzle opening,
A liquid droplet ejection apparatus, wherein the flow path forming portion is displaced by driving the piezoelectric element. The droplet discharge device according to claim 1 or 2,
The piezoelectric element is provided for each of the plurality of nozzle openings,
The liquid droplet ejection apparatus, wherein the drive control device drives the plurality of piezoelectric elements in synchronization. The droplet discharge device according to claim 3.
The droplet discharge head is provided for each of a plurality of nozzle openings, and a plurality of flow paths for guiding the liquid material to the nozzle openings,
A liquid droplet ejection apparatus comprising: a liquid reservoir portion that is connected to each of the plurality of flow paths and stores the liquid material. A liquid material agitation method for a droplet discharge head that discharges a liquid droplet from a nozzle opening by driving a piezoelectric element,
Closing the nozzle opening;
And a step of driving the piezoelectric element in a state in which the nozzle opening is closed. In the liquid substance stirring method of the droplet discharge head according to claim 5,
A flow path forming portion that forms a flow path for guiding the liquid material to the nozzle opening;
A liquid material agitation method for a droplet discharge head, wherein the flow path forming portion is displaced by driving the piezoelectric element. In the liquid substance stirring method of the droplet discharge head according to claim 5 or 6,
The piezoelectric element is provided for each of the plurality of nozzle openings,
A liquid material stirring method for a droplet discharge head, wherein the plurality of piezoelectric elements are driven synchronously. In the liquid substance stirring method of the droplet discharge head according to claim 7,
The droplet discharge head is provided for each of a plurality of nozzle openings, and a plurality of flow paths for guiding the liquid material to the nozzle openings,
A liquid stirring method for a liquid droplet ejection head, comprising: a liquid reservoir portion that is connected to each of the plurality of flow paths and stores the liquid material.

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