JP2012066194A - Droplet discharge device, and method for discharging liquid body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the time required for changing the type of a liquid body.SOLUTION: This droplet discharge device includes: a second supply pipe 119 for leading a functional fluid 53 in a second tank 117 to a discharge head 33; a filter 124 arranged in an intermediate part of the second supply pipe 119; a first valve 127 arranged between the second tank 117 and the filter 124 for opening/closing the second supply pipe 119; a bypass pipe 120 branched from the second supply pipe 119 between the second tank 117 and the first valve 127 and merging in the second supply pipe 119 between the filter 124 and the discharge head 33 after bypassing the filter 124; a second valve 129 for opening/closing the bypass pipe 120; a first discharge pipe 121 branched from the second supply pipe 119 between the first valve 127 and the filter 124 for discharging the functional fluid 53 to the outside of the second supply pipe 119; and a third valve 131 for opening/closing the first discharge pipe 121.

Description

  The present invention relates to a droplet discharge device, a liquid discharge method, and the like.

2. Description of the Related Art Conventionally, a droplet discharge device including a discharge head that can discharge a liquid material as droplets is known. In such a droplet discharge device, it is possible to draw various patterns with liquid materials on various media by discharging droplets from the discharge head.
In such a droplet discharge device, a configuration including a supply pipe that guides the liquid in the tank to the discharge head and a recovery pipe that branches from the supply pipe and guides the liquid to the recovery tank is known (for example, Patent Document 1).

JP 2008-49636 A

  In the droplet discharge device described in Patent Document 1, a recovery pipe that branches from the supply pipe is provided between the tank and the discharge head. Therefore, the liquid material remaining in the tank and the supply pipe is passed through the recovery pipe. Can be recovered quickly.

  By the way, in such a droplet discharge device, it is possible to adopt a configuration in which a filter for trapping (capturing) foreign matter in the liquid is interposed between the tank and the discharge head. In a droplet discharge device provided with a filter for capturing foreign matter, foreign matter mixed in the liquid is captured by the filter. As a result, it is possible to easily suppress the entry of foreign matter into the ejection head. As a result, it is possible to easily suppress a decrease in discharge performance in the discharge head, and thus it is possible to easily suppress a decrease in drawing quality in the droplet discharge device.

Here, in the liquid droplet ejection apparatus described in Patent Document 1, for example, when changing the type of the liquid material, the liquid material remaining in the tank and the supply pipe is not collected through the ejection head, and the collection pipe is not used. It can be recovered via. As a result, the type of the liquid material can be quickly changed.
However, in this droplet discharge device, the foreign matter captured by the filter remains on the filter even if the type of the liquid material is changed. Such foreign substances may include, for example, those generated by separation of a part of the liquid composition components. It is considered that such a foreign substance induces the generation of a new foreign substance when exposed to a new type of liquid. For this reason, in the conventional droplet discharge device, when changing the type of the liquid material, operations such as cleaning of the filter and replacement of the filter may be involved.
That is, the conventional droplet discharge device has a problem that it is difficult to shorten the time required for changing the type of the liquid material.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A discharge head that discharges a liquid material, a tank that stores the liquid material, a liquid guide path that guides the liquid material in the tank to the discharge head, and a midway of the liquid guide path. A filter for filtering the liquid material flowing through the liquid conduit, a first valve provided between the tank and the filter in the liquid conduit, and opening and closing the liquid conduit; the tank and the first A bypass route that branches from the liquid conduit between the valve and bypasses the filter and then merges with the liquid conduit between the filter and the discharge head; and A second valve that opens and closes a bypass, and a discharge path that branches from the liquid introduction path between the first valve and the filter, and that discharges the liquid material in the liquid introduction path to the outside of the liquid introduction path; , Provided in the discharge path , Having a third valve for opening and closing the discharge passage, the droplet discharge device, characterized in that.

The droplet discharge device according to this application example includes a discharge head, a tank, a liquid introduction path, a filter, a first valve, a bypass, a second valve, a discharge path, and a third valve. .
The discharge head discharges the liquid material.
The tank stores a liquid material.
The liquid guide path guides the liquid in the tank to the discharge head.
The filter is provided in the middle of the liquid introduction path. The filter filters the liquid material flowing through the liquid introduction path.
The first valve is provided between the tank and the filter in the liquid introduction path. The first valve opens and closes the liquid introduction path.
The bypass route branches from the liquid introduction path between the tank and the first valve. The bypass circuit bypasses the filter and then joins the liquid guide path between the filter and the ejection head.
The second valve is provided in the bypass. The second valve opens and closes the bypass.
The discharge path branches off from the liquid introduction path between the first valve and the filter. The discharge path discharges the liquid material in the liquid guide path to the outside of the liquid guide path.
The third valve is provided in the discharge path. The third valve opens and closes the discharge path.

  In this droplet discharge device, by closing the first valve and opening the second valve and the third valve, the liquid material is bypassed from the tank side by a detour, and the bypassed liquid material is discharged from the discharge head side. After the filter is made to flow backward, it can be discharged out of the liquid introduction path through the discharge path. In this droplet discharge device, since the liquid material can flow back from the discharge head side of the filter toward the tank side, foreign matters remaining on the tank side of the filter can be removed from the filter. That is, the filter can be easily purified. And the foreign material removed from the filter can be discharged | emitted out of a liquid introduction path from a discharge path with a liquid. As a result, the liquid remaining in the liquid introduction path and the foreign matter remaining in the filter can be discharged from the discharge path, so that the time required for changing the type of the liquid can be easily shortened.

  Application Example 2 In the above-described liquid droplet ejection device, the liquid is branched from the liquid introduction path between the filter and the ejection head, and the liquid material in the liquid introduction path is discharged out of the liquid introduction path. And a fourth valve that is provided in the second discharge path and opens and closes the second discharge path.

The droplet discharge device of this application example includes a second discharge path and a fourth valve.
The second discharge path branches off from the liquid introduction path between the filter and the discharge head. The second discharge path discharges the liquid material in the liquid guide path to the outside of the liquid guide path.
The fourth valve is provided in the second discharge path. The fourth valve opens and closes the second discharge path.
In this droplet discharge device, by closing the second valve and the third valve and opening the first valve and the fourth valve, the liquid material is discharged from the tank side through the filter to the outside of the liquid introduction path through the second discharge path. can do. As a result, the liquid material can flow backward from the discharge head side of the filter toward the tank side, or the liquid material can flow forward from the tank side of the filter toward the discharge head side. As a result, for example, when new foreign matter is trapped on the discharge head side of the filter when the liquid is made to flow backward, the foreign matter remaining on the discharge head side of the filter is removed from the filter by causing the liquid to flow forward. can do. And the foreign material removed from the filter can be discharged | emitted out of a liquid introduction path from a 2nd discharge path with a liquid body. This makes it easier to purify the filter.

  [Application Example 3] The liquid material in which the liquid material is caused to flow backward from the discharge head side toward the tank side of the filter provided in the middle of the liquid guide path for guiding the liquid material in the tank to the discharge head. Is discharged between the filter and the tank from the inside of the liquid introduction path to the outside of the liquid introduction path.

  The liquid material discharge method of this application example is a method of discharging the liquid material in the liquid guide path that guides the liquid material in the tank to the discharge head to the outside of the liquid guide path. In this method of discharging the liquid material, the liquid material is caused to flow backward from the discharge head side of the filter provided in the middle of the liquid introduction path toward the tank side, and the reversely flowed liquid material is introduced between the filter and the tank. Drain from the inside of the passage to the outside of the liquid introduction passage. In this liquid material discharging method, the liquid material is caused to flow backward from the discharge head side of the filter toward the tank side, so that foreign matters remaining on the tank side of the filter can be removed from the filter. That is, the filter can be easily purified. And the foreign material removed from the filter can be discharged | emitted out of a liquid introduction path with a liquid body. As a result, the liquid material remaining in the liquid introduction path and the foreign matter remaining in the filter can be discharged out of the liquid introduction path, so that the time required for changing the type of the liquid material can be easily shortened.

  Application Example 4 In the above-described liquid material discharge method, the liquid material is discharged between the filter and the tank from the inside of the liquid introduction path to the outside of the liquid introduction path, and then the tank of the filter. The liquid material is made to flow forward from the side toward the discharge head side, and the forward-flowed liquid material is discharged from the liquid guide path to the outside of the liquid guide path between the filter and the discharge head. A method for discharging a liquid material.

  In this application example, after the liquid material is discharged out of the liquid transfer path between the filter and the tank, the liquid material is allowed to flow forward from the tank side of the filter toward the discharge head side. Residual foreign matter can be removed from the filter. And the foreign material removed from the filter can be discharged | emitted out of a liquid introduction path between a filter and an ejection head with a liquid. This makes it easier to purify the filter.

FIG. 2 is a perspective view illustrating a schematic configuration of a droplet discharge device according to the present embodiment. The front view when the carriage in this embodiment is seen in the A viewing direction in FIG. FIG. 6 is a bottom view of the ejection head in the present embodiment. Sectional drawing in the BB line in FIG. Sectional drawing in the CC line | wire in FIG. The figure which shows the schematic structure of the supply apparatus in this embodiment. The figure which shows the flow of the change method of the functional liquid in this embodiment. The figure which shows the flow of the extraction process in this embodiment.

  Embodiments will be described with reference to the drawings. In addition, in each drawing, in order to make each structure the size which can be recognized, the structure and the scale of a member may differ.

As shown in FIG. 1, which is a perspective view showing a schematic configuration, the droplet discharge device 1 in the present embodiment includes a workpiece transfer device 3, a carriage 7, a capping device 9, and a carriage transfer device 11. is doing.
The carriage 7 is provided with a head unit 13.
In the droplet discharge device 1, the liquid material is discharged from the head unit 13 as droplets while changing the relative position of the head unit 13 and the workpiece W such as a substrate in a plan view. A desired pattern can be drawn. In the figure, the Y direction indicates the moving direction of the workpiece W, and the X direction indicates a direction orthogonal to the Y direction in plan view. A direction orthogonal to the XY plane defined by the X direction and the Y direction is defined as the Z direction.

Such a droplet discharge device 1 can be applied to, for example, the manufacture of a color filter used for a liquid crystal display panel or the like, or the manufacture of an organic EL device.
In the case of a color filter having three color filter elements of red, green, and blue, the droplet discharge device 1 can be suitably used, for example, in a process of forming red, green, and blue colored layers on a substrate. In this case, each liquid material corresponding to each colored layer is ejected from the head unit 13 as droplets onto the work W, whereby the patterns of the red, green, and blue filter elements are drawn on the work W.
Further, in the manufacture of an organic EL device, for example, it can be suitably used in a step of forming a functional layer (organic layer) corresponding to each color for each of red, green and blue pixels. In this case, each liquid material corresponding to the functional layer of each color is ejected from the head unit 13 as droplets onto the work W, whereby the patterns of the red, green, and blue functional layers are drawn on the work W.

Here, the details of each component of the droplet discharge device 1 will be described.
As illustrated in FIG. 1, the work transfer device 3 includes a surface plate 21, a guide rail 23 a, a guide rail 23 b, and a work table 25.
The surface plate 21 is made of a material having a small coefficient of thermal expansion, such as stone, and is placed so as to extend along the Y direction. The guide rail 23 a and the guide rail 23 b are disposed on the upper surface 21 a of the surface plate 21. Each of the guide rail 23a and the guide rail 23b extends along the Y direction. The guide rail 23a and the guide rail 23b are arranged in a state where there is a gap in the X direction.

The work table 25 is provided in a state facing the upper surface 21a of the surface plate 21 with the guide rail 23a and the guide rail 23b interposed therebetween. The work table 25 is placed on the guide rail 23a and the guide rail 23b in a state of floating from the surface plate 21. The work table 25 has a placement surface 25a that is a surface on which the workpiece W is placed. The placement surface 25a is directed to the side (upper side) opposite to the surface plate 21 side. The work table 25 is guided along the Y direction by the guide rail 23a and the guide rail 23b, and is configured to be able to reciprocate on the surface plate 21 along the Y direction.
The work table 25 is configured to reciprocate in the Y direction by a moving mechanism and a power source (not shown). As the moving mechanism, for example, a mechanism using a ball screw or a linear guide may be employed. In the present embodiment, a work conveyance motor (not shown) is employed as a power source for moving the work table 25 along the Y direction. As the work transfer motor, various motors such as a stepping motor, a servo motor, and a linear motor can be adopted.
The power from the work transport motor is transmitted to the work table 25 through the moving mechanism. Thereby, the work table 25 can reciprocate along the guide rail 23a and the guide rail 23b, that is, along the Y direction. That is, the workpiece transfer device 3 can reciprocate the workpiece W placed on the placement surface 25a of the workpiece table 25 along the Y direction.

The head unit 13 includes a head plate 31 and an ejection head 33 as shown in FIG. 2 which is a front view when the carriage 7 is viewed in the direction A in FIG.
As shown in FIG. 3 which is a bottom view, the discharge head 33 has a nozzle surface 35. A plurality of nozzles 37 are formed on the nozzle surface 35. In FIG. 3, the nozzles 37 are exaggerated and the number of the nozzles 37 is reduced in order to easily show the nozzles 37.
In the ejection head 33, the plurality of nozzles 37 constitute four nozzle rows 39 arranged along the Y direction. The four nozzle rows 39 are arranged in a state where there is a gap in the X direction. In each nozzle row 39, the plurality of nozzles 37 are formed at a predetermined nozzle interval P along the Y direction.
Hereinafter, when each of the four nozzle rows 39 is identified, the notation of the nozzle row 39a, the nozzle row 39b, the nozzle row 39c, and the nozzle row 39d is used.
In the ejection head 33, the nozzle row 39a and the nozzle row 39b are shifted from each other by a distance of P / 2 in the Y direction. The nozzle row 39c and the nozzle row 39d are also shifted from each other by a distance of P / 2 in the Y direction.

The ejection head 33 includes a nozzle plate 46, a cavity plate 47, a diaphragm 48, and a plurality of piezoelectric elements 49, as shown in FIG. 4 which is a cross-sectional view taken along the line BB in FIG. is doing.
The nozzle plate 46 has a nozzle surface 35. The plurality of nozzles 37 are provided on the nozzle plate 46.
The cavity plate 47 is provided on the surface opposite to the nozzle surface 35 of the nozzle plate 46. A plurality of cavities 51 are formed in the cavity plate 47. Each cavity 51 is provided corresponding to each nozzle 37 and communicates with each corresponding nozzle 37. The functional liquid 53 is supplied to each cavity 51 from a tank (not shown).

The diaphragm 48 is provided on the surface of the cavity plate 47 opposite to the nozzle plate 46 side. The vibration plate 48 vibrates in the Z direction (longitudinal vibration), thereby enlarging or reducing the volume in the cavity 51.
The plurality of piezoelectric elements 49 are respectively provided on the surface of the diaphragm 48 opposite to the cavity plate 47 side. Each piezoelectric element 49 is provided corresponding to each cavity 51 and faces each cavity 51 with the diaphragm 48 interposed therebetween. Each piezoelectric element 49 expands based on the drive signal. Thereby, the diaphragm 48 reduces the volume in the cavity 51. At this time, pressure is applied to the functional liquid 53 in the cavity 51. As a result, the functional liquid 53 is discharged as droplets 55 from the nozzle 37. The method of discharging the droplet 55 by the discharge head 33 is one of ink jet methods. The ink jet method is one of coating methods.

As shown in FIG. 2, the ejection head 33 having the above configuration is supported by the head plate 31 with the nozzle surface 35 protruding from the head plate 31.
As shown in FIG. 2, the carriage 7 supports the head unit 13. Here, the head unit 13 is supported by the carriage 7 with the nozzle surface 35 facing downward in the Z direction.
As described above, the functional liquid 53 can be applied to the workpiece W from the ejection head 33.
In the present embodiment, the longitudinal vibration type piezoelectric element 49 is adopted, but the pressurizing means for applying pressure to the functional liquid 53 is not limited to this, and for example, the lower electrode and the piezoelectric layer A flexural deformation type piezoelectric element in which an electrode and an upper electrode are laminated may be employed. Further, as the pressurizing means, a so-called electrostatic actuator that generates static electricity between the diaphragm and the electrode, deforms the diaphragm by electrostatic force, and ejects droplets from the nozzles can be employed. Furthermore, the structure which generate | occur | produces a bubble in a nozzle using a heat generating body, and gives a pressure to a functional liquid with the bubble may be employ | adopted.

  The capping device 9 is a device that covers the ejection head 33. In the droplet discharge device 1, the liquid component of the liquid (functional liquid 53) may evaporate from the nozzle 37 of the discharge head 33. Generally, when the liquid component in the liquid material evaporates, the viscosity of the liquid material increases. When the liquid component in the liquid in the discharge head 33 evaporates from the nozzle 37, the nozzle 37 may be clogged. The capping device 9 covers the discharge head 33 to keep the liquid component in the liquid material from evaporating from the nozzle 37 low. As a result, the occurrence of clogging in the nozzle 37 can be kept low.

The capping device 9 includes a support base 71, a cap portion 73, a tube 75, a valve 76, and a suction pump 77, as shown in FIG. is doing. The cap unit 73 includes a housing 79, a spring 81, a frame 83, a packing 85, and a stopper 87.
The cap unit 73 is placed on the support base 71. The support base 71 supports the casing 79 of the cap portion 73.
The spring 81 is accommodated in the housing 79 and supported by the bottom 79 a of the housing 79.
The frame 83 is accommodated in the housing 79 and is supported by the housing 79 via a spring 81.

The spring 81 is sandwiched between the bottom 79a of the housing 79 and the bottom surface 83a of the frame 83, and urges the bottom surface 83a of the frame 83 upward.
The packing 85 is made of an elastic body such as rubber or elastomer, and has a shape in which a cross section is recessed downward in the Z direction. The packing 85 is accommodated in the frame 83. When the packing 85 contacts the peripheral edge of the discharge head 33, a space 89 is formed in a region surrounded by the concave shape of the packing 85 and the discharge head 33. The packing 85 has a function of increasing the airtightness of the space 89.
The stopper 87 is provided on the upper surface of the housing 79, and restricts the frame 83 biased by the spring 81 from protruding out of the housing 79.

The tube 75 has one end connected to the valve 76 and the other end connected to the packing 85. A suction pump 77 is provided on the side of the valve 76 opposite to the packing 85 side. The suction pump 77 communicates with the space 89 from the inside of the support base 71 through the casing 79, the frame 83, and the packing 85 by the tube 75 through the valve 76. As the suction pump 77, various vacuum pumps such as a fluid-operated pump such as an ejector pump, a mechanical pump, and a rotary pump can be employed.
Here, in the capping device 9, the liquid material can be sucked out of the discharge head 33 from the nozzle 37 of the discharge head 33 by operating the suction pump 77 with the valve 76 opened. The operation of sucking the liquid material from the nozzle 37 to the outside of the ejection head 33 is called a suction operation. The suction operation is performed when the liquid material is forcibly discharged from the nozzle 37 of the ejection head 33.

  The suction operation is performed, for example, when recovering the performance of ejecting the droplets 55 in the nozzle 37 (hereinafter referred to as ejection performance). For example, when the viscosity of the liquid in the nozzle 37 becomes high, the flight path of the discharged droplet 55 may be bent or the discharge of the droplet 55 may be hindered. By performing the suction operation, it is possible to recover such a drop in the discharge performance.

As shown in FIG. 1, the carriage transport device 11 includes a gantry 101 and a guide rail 103.
The gantry 101 extends in the X direction and straddles the workpiece transfer device 3 in the X direction. The gantry 101 faces the work transfer device 3 on the side opposite to the surface plate 21 side of the work table 25. The gantry 101 is supported by a pair of support columns 107. The pair of support columns 107 are provided at positions facing each other in the X direction with the surface plate 21 interposed therebetween.
In the following, when identifying each of the pair of columns 107, the notation of columns 107a and columns 107b is used. The support column 107a and the support column 107b protrude above the work table 25 in the Z direction. Thereby, a gap is maintained between the gantry 101 and the work table 25.

The guide rail 103 is provided on the surface plate 21 side of the gantry 101. The guide rail 103 extends along the X direction and is provided across the width of the gantry 101 in the X direction.
The carriage 7 described above is supported by the guide rail 103. In a state where the carriage 7 is supported by the guide rail 103, the nozzle surface 35 of the ejection head 33 faces the work table 25 in the Z direction. The carriage 7 is guided along the X direction by the guide rail 103 and is supported by the guide rail 103 so as to be capable of reciprocating in the X direction. In a plan view, in a state where the carriage 7 overlaps the work table 25, the nozzle surface 35 and the mounting surface 25a of the work table 25 face each other with a gap therebetween.

The carriage 7 is configured to reciprocate in the X direction by a moving mechanism and a power source (not shown). As the moving mechanism, for example, a mechanism using a ball screw or a linear guide may be employed. In the present embodiment, a carriage transport motor (not shown) is employed as a power source for moving the carriage 7 along the X direction. As the carriage conveyance motor, various motors such as a stepping motor, a servo motor, and a linear motor can be employed.
The power from the carriage transport motor is transmitted to the carriage 7 through the moving mechanism. Thus, the carriage 7 can reciprocate along the guide rail 103, that is, along the X direction. That is, the carriage conveyance device 11 can reciprocate the head unit 13 supported by the carriage 7 along the X direction.
In the droplet discharge device 1 having the above-described configuration, the droplet 55 is discharged from the discharge head 33 while the discharge head 33 and the workpiece W are relatively reciprocated while the discharge head 33 is opposed to the workpiece W. By doing so, the pattern is drawn on the workpiece W.

Here, the droplet discharge device 1 has a supply device 111 as shown in FIG. The supply device 111 is a device that supplies the functional liquid 53 to the ejection head 33.
The supply device 111 includes a first tank 113, a first supply pipe 115, a second tank 117, a second supply pipe 119, a detour pipe 120, a first discharge pipe 121, a second discharge pipe 123, The filter 124, the supply valve 125, the first valve 127, the second valve 129, the third valve 131, and the fourth valve 133 are provided.
The first tank 113 and the second tank 117 are containers for storing the functional liquid 53, respectively.
The first supply pipe 115 communicates from the first tank 113 to the second tank 117. The functional liquid 53 in the first tank 113 is supplied into the second tank 117 through the first supply pipe 115.

The first supply pipe 115 is provided with a supply valve 125. The supply valve 125 opens and closes the flow path of the first supply pipe 115. When the supply valve 125 is in the open state, the inside of the first tank 113 and the inside of the second tank 117 communicate with each other.
Note that the inside of the first tank 113 is maintained at a pressure higher than the pressure outside the first tank 113 (in this embodiment, atmospheric pressure). For this reason, when the supply valve 125 is open, the functional liquid 53 in the first tank 113 is supplied into the second tank 117 via the first supply pipe 115.

The second supply pipe 119 communicates with the discharge head 33 from the second tank 117. The functional liquid 53 in the second tank 117 is supplied to the ejection head 33 via the second supply pipe 119.
The second supply pipe 119 is provided with a filter 124. The filter 124 captures foreign matter or bubbles contained in the functional liquid 53 flowing through the second supply pipe 119. As a result, even if foreign matter or bubbles are included in the functional liquid 53 flowing through the second supply pipe 119 from the second tank 117 toward the discharge head 33, the foreign matter or bubbles can reach the discharge head 33. It can be kept low. As a result, the drawing quality in the droplet discharge device 1 can be easily maintained.
In the second supply pipe 119, a first valve 127 is provided between the second tank 117 and the filter 124. The first valve 127 opens and closes the flow path of the second supply pipe 119. When the first valve 127 is open, the functional liquid 53 in the second tank 117 can be guided to the ejection head 33.

  In the present embodiment, the water head pressure between the second tank 117 and the discharge head 33 is maintained within a predetermined range. For this reason, the pressure of the functional liquid 53 in the ejection head 33 can be easily maintained within a predetermined range regardless of the amount of the functional liquid 53 in the second tank 117. As a result, the discharge performance of the droplets 55 in the discharge head 33 can be easily maintained. In the present embodiment, the second tank 117 has flexibility. For this reason, it is possible to easily suppress the fluctuation in the pressure in the second tank 117 due to the increase / decrease in the functional liquid 53 in the second tank 117. As a result, the water head pressure between the second tank 117 and the ejection head 33 can be easily maintained. Examples of the flexible second tank 117 include a film pack.

In the present embodiment, the amount of the functional liquid 53 in the second tank 117 is controlled within a predetermined range. When the amount of the functional liquid 53 in the second tank 117 falls below a predetermined range, the supply valve 125 is controlled to be opened. As a result, the functional liquid 53 is supplied into the second tank 117.
On the other hand, when the amount of the functional liquid 53 in the second tank 117 exceeds a predetermined range, the supply valve 125 is controlled to be closed. Thereby, the supply of the functional liquid 53 into the second tank 117 is stopped.
The functional liquid 53 in the first tank 113 is stably supplied to the ejection head 33 by the supply device 111 having the above configuration.

The bypass pipe 120 branches from the second supply pipe 119 between the second tank 117 and the first valve 127. The bypass pipe 120 bypasses the filter 124 and then joins the second supply pipe 119 between the filter 124 and the discharge head 33.
A second valve 129 is provided in the bypass pipe 120. The second valve 129 opens and closes the flow path of the bypass pipe 120.
The first discharge pipe 121 branches from the second supply pipe 119 between the first valve 127 and the filter 124. The first discharge pipe 121 discharges the functional liquid 53 in the second supply pipe 119 to the outside of the second supply pipe 119. In the present embodiment, the first discharge pipe 121 branched from the second supply pipe 119 communicates with the suction pump 77.
The first discharge pipe 121 is provided with a third valve 131. The third valve 131 opens and closes the flow path of the first discharge pipe 121.

The second discharge pipe 123 branches from the second supply pipe 119 between the filter 124 and the discharge head 33. The second discharge pipe 123 discharges the functional liquid 53 in the second supply pipe 119 to the outside of the second supply pipe 119. In the present embodiment, the second discharge pipe 123 branched from the second supply pipe 119 communicates with the suction pump 77.
The second exhaust pipe 123 is provided with a fourth valve 133. The fourth valve 133 opens and closes the flow path of the second discharge pipe 123.
Here, a position where the second discharge pipe 123 branches from the second supply pipe 119 is referred to as a branch point 137. A position where the bypass pipe 120 joins the second supply pipe 119 is referred to as a joining point 139.
In the example shown in FIG. 6, the junction point 139 is located between the filter 124 and the branch point 137. However, the position of the junction point 139 is not limited to this, and may be between the branch point 137 and the ejection head 33.

A method for changing the type of the functional liquid 53 (hereinafter referred to as a method for changing the functional liquid 53) will be described.
As shown in FIG. 7, the method for changing the functional liquid 53 includes an extraction step S1, a cleaning step S2, and a tank replacement step S3.
In the extraction step S1, the functional liquid 53 remaining in the second tank 117 and the second supply pipe 119 is extracted.
After the extraction step S1, in the cleaning step S2, the first supply pipe 115, the second tank 117, the second supply pipe 119, the discharge head 33, the bypass pipe 120, the first discharge pipe 121, and the second discharge pipe 123 are respectively provided. Pour cleaning solution. Thereby, the flow path of the functional liquid 53 can be washed.
After the cleaning step S2, in the tank replacement step S3, the type of the functional liquid 53 is changed by replacing the first tank 113. That is, the type of the functional liquid 53 is changed for each first tank 113.
The type of the functional liquid 53 can be changed by the method for changing the functional liquid 53 described above.

As shown in FIG. 8, the extraction step S1 includes a first discharge step S101, a second discharge step S102, a third discharge step S103, and a fourth discharge step S104.
In the first discharge step S101, first, the valve 76, the supply valve 125, the first valve 127, and the fourth valve 133 shown in FIG. 6 are closed, and the second valve 129 and the third valve 131 are opened. As a result, a route (hereinafter referred to as the first route) from the second tank 117 to the suction pump 77 via the bypass pipe 120 in the middle of the second supply pipe 119, through the filter 124 and then through the first discharge pipe 121. Called).
The extraction step S1 is performed in a state where the ejection head 33 is covered with the capping device 9, that is, the ejection head 33 and the cap portion 73 are in contact with each other.

Here, in this embodiment, in the second supply pipe 119, the direction from the second tank 117 toward the ejection head 33 is defined as the forward direction. In the first path, the functional liquid 53 flows backward in the direction opposite to the forward direction in the section from the junction point 139 to the branch point 141. The branch point 141 is a position where the first discharge pipe 121 branches from the second supply pipe 119.
Next, the suction pump 77 is operated. Accordingly, the functional liquid 53 can be discharged from the second supply pipe 119 along the first path.

Next, in the second discharge step S102 shown in FIG. 8, the second valve 129 and the third valve 131 shown in FIG. 6 are closed and the first valve 127 and the fourth valve 133 are opened, and then the suction pump 77 is activated.
At this time, the valve 76 and the supply valve 125 remain closed. As a result, a path (hereinafter referred to as a second path) is formed which passes from the second tank 117 through the filter 124 of the second supply pipe 119 to the second discharge pipe 123 at the branch point 137 and reaches the suction pump 77. Is done.
Through the second discharge step S102, the functional liquid 53 can be discharged from the second supply pipe 119 along the second path.
It is preferable that the functional liquid 53 remaining in the second tank 117 is removed by the first discharge step S101 and the second discharge step S102.

Next, in the third discharge step S103 shown in FIG. 8, the first valve 127 shown in FIG. 6 is closed, and then the suction pump 77 is operated.
At this time, the fourth valve 133 remains open. In addition, the valve 76, the supply valve 125, the second valve 129, and the third valve 131 remain closed. As a result, a path (hereinafter referred to as a third path) is formed which flows backward from the discharge head 33 through the second supply pipe 119 and branches to the second discharge pipe 123 at the branch point 137 to reach the suction pump 77.
Through the third discharge step S103, the functional liquid 53 can be discharged from the second supply pipe 119 along the third path.

Next, in the fourth discharging step S104 shown in FIG. 8, the fourth valve 133 is closed and the first valve 127 and the valve 76 are opened, and then the suction pump 77 is operated.
At this time, the supply valve 125, the second valve 129, the third valve 131, and the fourth valve 133 remain closed.
Through the fourth discharging step S104, the functional liquid 53 remaining in the discharge head 33 can be discharged from the nozzle 37 to the cap portion 73. Note that the fourth discharging step S104 corresponds to the suction operation described above.
The functional liquid 53 remaining in the second tank 117 and the second supply pipe 119 can be extracted by the extraction step S1 having the above configuration.

In the present embodiment, the second tank 117 corresponds to the tank, the second supply pipe 119 corresponds to the liquid introduction path, the bypass pipe 120 corresponds to the bypass path, the first discharge pipe 121 corresponds to the discharge path, The second discharge pipe 123 corresponds to the second discharge path.
In the present embodiment, the functional liquid 53 can be discharged from the second supply pipe 119 along the first path in the first discharge step S101. In the first path, the functional liquid 53 can flow back in the section from the junction point 139 to the branch point 141 shown in FIG.
A filter 124 is interposed between the junction 139 and the branch point 141. That is, in the first discharge step S101, the functional liquid 53 can be made to flow backward from the discharge head 33 side of the filter 124 toward the second tank 117 side. For this reason, foreign matters remaining on the second tank 117 side of the filter 124 can be removed from the filter 124. Thereby, the filter 124 can be easily purified.

The foreign matter removed from the filter 124 can be discharged out of the second supply pipe 119 from the first discharge pipe 121 together with the functional liquid 53. As a result, the functional liquid 53 remaining in the second supply pipe 119 and the foreign matter remaining in the filter 124 can be discharged from the first discharge pipe 121.
For this reason, when changing the type of the functional liquid 53, it is possible to easily omit operations such as cleaning and replacement of the filter 124. As a result, the time required for changing the type of the functional liquid 53 can be easily shortened.

In the present embodiment, the functional liquid 53 can be discharged from the second supply pipe 119 along the second path in the second discharge step S102. In the second path, the functional liquid 53 can flow in the forward direction (forward flow) in the section from the second tank 117 to the branch point 137 shown in FIG.
That is, in the second discharge step S102, the functional liquid 53 can be made to flow forward from the second tank 117 side of the filter 124 toward the discharge head 33 side.
Here, in the first discharge step S101 described above, the functional liquid 53 flows backward from the discharge head 33 side of the filter 124 toward the second tank 117 side. At this time, it is conceivable that a new foreign substance is captured on the ejection head 33 side of the filter 124.

In contrast, in the present embodiment, in the second discharge step S102, the functional liquid 53 is allowed to flow forward from the second tank 117 side of the filter 124 toward the discharge head 33 side, and therefore remains on the discharge head 33 side of the filter 124. Foreign matter can be removed from the filter 124. Thereby, the filter 124 can be further easily purified.
The foreign matter removed from the filter 124 can be discharged out of the second supply pipe 119 from the second discharge pipe 123 together with the functional liquid 53. As a result, the functional liquid 53 remaining in the second supply pipe 119 and the foreign matter remaining in the filter 124 can be discharged from the second discharge pipe 123.

In the present embodiment, a configuration in which the first discharge pipe 121 and the second discharge pipe 123 are connected to the suction pump 77 is employed. However, the configuration of the supply device 111 is not limited to this. As the supply device 111, for example, a configuration in which the first discharge pipe 121 and the second discharge pipe 123 are connected to another pump different from the suction pump 77 can be adopted.
Furthermore, as the supply apparatus 111, the structure which connects each of the 1st discharge pipe 121 and the 2nd discharge pipe 123 to a mutually different pump can be employ | adopted, for example.
In the present embodiment, the extraction step S1 is performed with the capping device 9 covering the ejection head 33. However, the present invention is not limited to this, and in the second supply pipe 119, the branch point 137 and the ejection head 33 are separated. A configuration in which a new opening / closing valve is provided in between and the opening / closing valve is closed may be employed.
In the present embodiment, the extraction step S1 is performed with the capping device 9 covering the ejection head 33, but the present invention is not limited to this. For example, in the third ejection step S103, the capping device 9 is removed from the ejection head 33. A configuration in a separated state can also be adopted.
In the present embodiment, the first discharge step S101 to the fourth discharge step S104 are performed as the extraction step S1, but in the cleaning step S2, the cleaning liquid is discharged by the first discharge step S101 to the fourth discharge step S104. Even so, the effect of effectively purifying the filter 124 can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Droplet discharge device, 9 ... Capping device, 13 ... Head unit, 33 ... Discharge head, 53 ... Functional liquid, 55 ... Droplet, 76 ... Valve, 77 ... Suction pump, 111 ... Supply device, 113 ... 1st Tank, 115 ... first supply pipe, 117 ... second tank, 119 ... second supply pipe, 120 ... detour pipe, 121 ... first discharge pipe, 123 ... second discharge pipe, 124 ... filter, 125 ... supply valve, 127: First valve, 129: Second valve, 131: Third valve, 133: Fourth valve, 135: Branch point, 141: Branch point, W: Workpiece

Claims (4)

An ejection head for ejecting a liquid material;
A tank for storing the liquid material;
A liquid introduction path for guiding the liquid in the tank to the ejection head;
A filter provided in the middle of the liquid introduction path, for filtering the liquid material flowing through the liquid introduction path;
A first valve that is provided between the tank and the filter in the liquid conduit and opens and closes the liquid conduit;
A bypass that branches from the liquid guide path between the tank and the first valve, bypasses the filter, and then joins the liquid guide path between the filter and the discharge head;
A second valve provided in the detour to open and close the detour;
A discharge path that branches from the liquid introduction path between the first valve and the filter, and that discharges the liquid material in the liquid introduction path to the outside of the liquid introduction path;
A third valve provided in the discharge path and opening and closing the discharge path,
A droplet discharge apparatus characterized by the above. A second discharge path that branches from the liquid guide path between the filter and the discharge head and discharges the liquid material in the liquid guide path to the outside of the liquid guide path;
A fourth valve provided in the second discharge path and opening and closing the second discharge path,
The droplet discharge device according to claim 1. The liquid material is caused to flow backward from the discharge head side toward the tank side of the filter provided in the middle of the liquid guide path for guiding the liquid material in the tank to the discharge head, Discharging from the inside of the liquid introduction path to the outside of the liquid introduction path with the tank;
A method for discharging a liquid material. After discharging the liquid material from the inside of the liquid introduction path between the filter and the tank to the outside of the liquid introduction path,
The liquid material is made to flow forward from the tank side to the discharge head side of the filter, and the forward-flowed liquid material is passed between the filter and the discharge head from inside the liquid introduction path to outside the liquid introduction path. To discharge,
The method for discharging a liquid material according to claim 3.

Images