JP2013166288A - Liquid droplet ejection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid droplet ejection device including satisfactory print quality by uniformizing a temperature in an entire head.SOLUTION: A liquid droplet ejection device has a head unit 54 where a plurality of liquid droplet ejection heads 17 for ejecting liquid droplets to a medium are arranged. The respective liquid droplet ejection heads 17 eject different liquid droplets to the medium. In the head unit 54, a liquid droplet ejection head 17 for ejecting liquid having a small viscosity change to a specific temperature change is disposed in the head unit 54, and a liquid droplet ejection head 17 for ejecting liquid having a large viscosity change to a specific temperature change is disposed outside the head unit 54.

Description

  The present invention relates to a droplet discharge device.

  Conventionally, by using a droplet discharge device provided with a droplet discharge head for discharging a liquid, a droplet (liquid) containing a functional film material is placed on an arbitrary position on a substrate, and the liquid is disposed. A technique is known in which a functional film is formed by drying the film.

  By the way, in the above technique, there is a technique for improving the drawing speed of droplets on a substrate by providing a large number of droplet discharge heads or increasing the total number of nozzles for discharging liquids by increasing the number of nozzle rows of the droplet discharge heads. (For example, refer to Patent Document 1). When the number of nozzles and the number of heads are increased as described above, the vicinity of the center of the nozzle array or the vicinity of the center of the head array is in a high temperature state, and the liquid viscosity decreases, resulting in an increase in droplets and a decrease in print quality. There is a fear. Therefore, in the above prior art, in order to prevent a decrease in print quality due to a temperature rise, a temperature sensor and a temperature control device are provided to adjust the temperature of the head and its peripheral portion so as to prevent a decrease in print quality. I have to.

JP 2009-288278 A

  However, in the above prior art, the nozzle row interval and the head interval are narrowly mixed to improve the drawing speed, so a temperature sensor and a temperature control device are additionally arranged near the center between the heads and near the center of the nozzle row. It was difficult to secure space for. Therefore, there is a problem that the temperature cannot be made uniform in the entire head, and good print quality cannot be obtained.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a droplet discharge device capable of suppressing a decrease in print quality due to temperature variations in the entire head.

  In order to solve the above-described problem, a droplet discharge device according to a first aspect is a droplet discharge device having a head unit in which a plurality of droplet discharge heads that discharge liquid droplets onto a medium are arranged. Each of the heads discharges the different liquid onto the medium, and in the head unit, the liquid droplet discharge head that discharges the liquid of a type having a small viscosity change with respect to a predetermined temperature fluctuation is disposed inside the head unit. The liquid droplet ejection head that ejects the liquid of a type having a large viscosity change with respect to the predetermined temperature variation is disposed outside the head unit.

The inner side of the head unit, that is, the inner side of the head unit, has a higher temperature than the outer side, and as a result of temperature variations between the heads, the liquid ejection accuracy may be reduced.
Therefore, according to the droplet discharge head of the present invention, a droplet discharge head that discharges a liquid having a small viscosity change, that is, a head that discharges a liquid that has a small influence on temperature fluctuations is disposed inside the head unit. The influence of temperature fluctuation can be reduced. In addition, a droplet discharge head that discharges liquid with a large viscosity change, that is, a head that discharges liquid that is greatly affected by temperature fluctuations, is a head unit that is cooled by touching the outside air and does not easily rise in temperature compared to the inside. Since it is arranged outside, the influence of temperature fluctuation is reduced.
Therefore, by suppressing the influence of the temperature fluctuation of the droplet discharge head inside and outside the head unit, the discharge accuracy of the entire head unit can be made uniform.

The droplet discharge device according to the second aspect is
In a droplet discharge apparatus having a droplet discharge head for discharging a liquid droplet onto a medium, the droplet discharge head has a nozzle forming surface on which a plurality of nozzle rows are formed, and the plurality of nozzle rows are A nozzle row that discharges the type of liquid that has a small viscosity change with respect to a predetermined temperature change is disposed inside the nozzle forming surface, and the nozzle row that discharges the type of liquid with a large viscosity change with respect to the predetermined temperature change is It is arranged outside the nozzle forming surface.

According to the droplet discharge head of the present invention, since the nozzle row that discharges a liquid having a small viscosity change, that is, the nozzle row that discharges a liquid that has little influence on temperature fluctuations, is disposed inside the nozzle formation surface. The influence of fluctuation can be reduced. In addition, nozzle rows that discharge liquids with large viscosity changes, that is, nozzle rows that discharge liquids that are greatly affected by temperature fluctuations, are placed outside the nozzle forming surface where the temperature rises less easily than inside due to contact with the outside air. Therefore, the influence of temperature fluctuation is reduced.
Therefore, it is possible to make the discharge accuracy of the entire droplet discharge head uniform by suppressing the influence of temperature fluctuations inside and outside the nozzle formation surface.

In the second aspect, a configuration including a head unit having a plurality of the droplet discharge heads may be employed.
According to this configuration, since a plurality of droplet discharge heads having a uniform overall temperature are provided, the discharge accuracy of the entire head unit can be made uniform.

  A droplet discharge device according to a third aspect is a droplet discharge device having a head unit in which a plurality of droplet discharge heads that discharge liquid droplets on a medium are arranged. The liquid droplets are ejected onto the medium, and in the head unit, the liquid droplet ejection head that ejects the type of liquid whose amount is smaller than a predetermined reference is disposed inside the head unit, and the head unit Further, the liquid droplet discharge head for discharging the liquid of a type having a large discharge amount is arranged outside the head unit.

According to the droplet discharge head of the present invention, since the head that generates a small amount of heat due to driving due to a small amount of liquid discharge is disposed inside the head unit, the influence of temperature fluctuations can be reduced. In addition, the head that generates a large amount of liquid and generates a large amount of heat when driven is cooled by touching the outside air and placed outside the head unit, where the temperature does not rise easily compared to the inside. Become.
Therefore, the temperature of the entire head unit can be made uniform by suppressing the influence of temperature fluctuations of the droplet discharge heads inside and outside the head unit.

  A droplet discharge device according to a fourth aspect is a droplet discharge device having a droplet discharge head for discharging a liquid droplet onto a medium, wherein the droplet discharge head is a nozzle forming surface on which a plurality of nozzle rows are formed. And the plurality of nozzle rows are arranged on the inner side of the nozzle forming surface of the droplet discharge head, and the nozzle rows for discharging the liquid of a type whose discharge amount is smaller than a predetermined reference Also, a nozzle row that discharges the type of liquid with a large discharge amount is arranged outside the nozzle formation surface.

According to the droplet discharge head of the present invention, since the nozzle row with a small amount of heat generated by driving due to a small amount of liquid discharge is arranged on the inner side of the nozzle formation surface, the influence of temperature fluctuation can be reduced. . In addition, since the nozzle row having a large liquid discharge amount and a large calorific value is cooled by the outside air, it is arranged outside the nozzle forming surface where the temperature does not rise easily compared to the inside, so that the influence of temperature fluctuation is reduced.
Therefore, the temperature of the entire droplet discharge head can be made uniform by suppressing the influence of temperature fluctuations inside and outside the nozzle formation surface.

In the fourth aspect, a plurality of droplet discharge heads may be provided.
According to this configuration, since the plurality of droplet discharge heads having the same overall temperature are provided, the temperature of the entire head unit can be made uniform.

  A droplet discharge device according to a fifth aspect is a droplet discharge device having a head unit in which a plurality of droplet discharge heads that discharge liquid droplets onto a medium are arranged. The head unit includes an outer portion of the head unit. The inner side is arranged so that the number of the droplet discharge heads is increased.

According to the droplet discharge head of the present invention, since a relatively large number of droplet discharge heads are arranged inside the head unit, the operating rate of each droplet discharge head can be suppressed, and as a result, the head unit The amount of heat generated on the inside of the glass can be reduced, and the occurrence of temperature fluctuation can be suppressed.
In addition, since the number of droplet discharge heads arranged outside the head unit is relatively reduced, the operating rate of each droplet discharge head increases and the amount of heat generation increases, but the outside of the head unit is exposed to the outside air. Since it is cooled by touching and the temperature does not rise easily compared to the inside, the occurrence of temperature fluctuations can be suppressed.
Therefore, the temperature of the entire head unit can be made uniform by suppressing the influence of temperature fluctuations of the droplet discharge heads inside and outside the head unit.

  A droplet discharge device according to a sixth aspect is a droplet discharge device having a droplet discharge head that discharges a liquid droplet from each nozzle of a plurality of nozzle rows to a medium. In the droplet discharge head, the nozzle The number of the nozzle rows is greater on the inner side than the outer side of the nozzle forming surface where the nozzles are formed.

According to the droplet discharge head of the present invention, since a relatively large number of nozzle rows are arranged on the inner side of the nozzle formation surface, the operation rate of each nozzle can be suppressed, and as a result, on the inner side of the nozzle formation surface. The amount of heat generation is reduced, and the occurrence of temperature fluctuation can be suppressed.
In addition, since the number of nozzle rows arranged outside the nozzle forming surface is relatively reduced, the operating rate of each nozzle is increased and the amount of heat generation is increased, but the outside of the nozzle forming surface is exposed to the outside air. Since it is cooled and the temperature does not rise easily compared to the central portion, the occurrence of temperature fluctuations can be suppressed.
Therefore, the temperature of the entire droplet discharge head can be made uniform by suppressing the influence of temperature fluctuations inside and outside the nozzle formation surface.

1 is a plan view showing a schematic configuration of a droplet discharge device according to a first embodiment. The side view which shows schematic structure of a droplet discharge apparatus. (A) is an external perspective view of the droplet discharge head as viewed from the nozzle plate side, (b) is a perspective sectional view showing a structure around the pressure chamber of the droplet discharge head, and (c) is a droplet discharge head. Sectional drawing which shows the structure of the discharge nozzle part. It is the figure which looked at the droplet discharge head from the nozzle plate side. It is the figure which looked at the droplet discharge head concerning a 2nd embodiment from the nozzle plate side. It is the figure which looked at the droplet discharge head concerning a 5th embodiment from the nozzle plate side. It is the figure which looked at the droplet discharge head concerning a 6th embodiment from the nozzle plate side.

Hereinafter, embodiments according to the droplet discharge device of the present invention will be described. The present embodiment is specifically described for better understanding of the gist of the invention, and does not limit the invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easier to understand, there is a case where a main part is shown in an enlarged manner for convenience, and the dimensional ratio of each component is the same as the actual one. Not necessarily.
Hereinafter, as an embodiment of the liquid droplet ejection apparatus of the present invention, an ink jet type liquid droplet ejection head capable of ejecting a functional liquid (liquid) including a material constituting a color element film is used, and a drawing object (medium) ) To form a desired drawing film by disposing the functional liquid on a substrate or the like.

(First embodiment)
FIG. 1 is a plan view showing a schematic configuration of a droplet discharge device according to the first embodiment. First, FIG. 2 is a side view showing a schematic configuration of the droplet discharge device. In the following description, the XYZ coordinate system is used for explanation, the Y direction is the movement direction of the droplet discharge head, the X direction is the direction orthogonal to the Y direction in the transport plane on which the workpiece is transported, and Z The direction corresponds to the vertical direction orthogonal to both the X direction and the Y direction.

  As shown in FIGS. 1 and 2, the droplet discharge device 1 includes a discharge unit 2 having a droplet discharge head 17 (see FIG. 3), a work unit 3, an inspection unit 4, and a maintenance unit 5. It has.

  The discharge unit 2 includes a plurality of droplet discharge heads 17 that discharge a functional liquid (liquid) corresponding to a liquid as droplets. The droplet discharge head 17 is moved in the Y-axis direction and moved to the moved position. A Y-axis table 12 for holding is provided. The work unit 3 includes a work mounting table 21 on which a work W that is a discharge target of liquid droplets discharged from the liquid droplet discharge head 17 is mounted. The inspection unit 4 includes a discharge inspection unit 18 and a weight measurement unit 19 for inspecting a discharge state from the droplet discharge head 17, and the weight measurement unit 19 is provided with a flushing unit 14. The maintenance unit 5 includes a suction unit 15 and a wiping unit 16 that maintain the droplet discharge head 17.

  The droplet discharge device 1 includes an X-axis support base 1A supported on a stone surface plate, and each unit is disposed on the X-axis support base 1A. The X-axis table 11 extends in the X-axis direction as the main scanning direction, is disposed on the X-axis support base 1A, and moves the workpiece mounting table 21 in the X-axis direction (main scanning direction). .

  The Y-axis table 12 of the discharge unit 2 is disposed on a pair of Y-axis support bases 7 and 7 spanned across the X-axis table 11 via a plurality of support columns 7A. Extending in the Y-axis direction. The discharge unit 2 includes a carriage unit 51 having six droplet discharge heads 17. The carriage unit 51 is suspended from the bridge plate 52. The bridge plate 52 is supported by the Y-axis table 12 via a Y-axis slider (not shown) so as to be slidable in the Y-axis direction. The Y-axis table 12 moves the bridge plate 52 (carriage unit 51) in the Y-axis direction (sub-scanning direction).

  In synchronism with the driving of the X-axis table 11 and the Y-axis table 12, the droplet discharge head 17 of the discharge unit 2 is driven to discharge, thereby discharging the functional liquid droplets on the workpiece mounting table 21. An arbitrary drawing pattern is drawn with the functional liquid on the placed work W.

  The discharge inspection unit 18 includes an inspection drawing unit 161 and an imaging unit 162. The inspection drawing unit 161 is fixed to the X-axis second slider 23 and is configured to move integrally with the weight measuring unit 19 and the flushing unit 14 that are also fixed to the X-axis second slider 23. The imaging unit 162 includes two inspection cameras 163 and a camera moving mechanism 164 that slidably supports the inspection camera 163 in the Y-axis direction.

  The suction unit 15 and the wiping unit 16 included in the maintenance unit 5 are disposed on the gantry 8 disposed at a position where the carriage unit 51 can be moved by the Y-axis table 12 while being detached from the X-axis table 11. Yes.

  The suction unit 15 includes a cap unit 15a, seals the nozzle forming surface 76a (see FIG. 3) of the droplet discharge head 17, and sucks the discharge nozzle 78 (see FIG. 3) to thereby drop the droplet discharge head 17. The functional liquid is forcibly discharged from the discharge nozzle 78. The wiping unit 16 includes a wiping sheet 16a sprayed with a cleaning liquid, and wipes (performs wiping) the nozzle forming surface 76a of the droplet discharge head 17 after suction. In this way, the suction unit 15 and the wiping unit 16 perform maintenance work for maintaining or recovering the function of the droplet discharge head 17 of the discharge unit 2.

  The X-axis table 11 includes an X-axis first slider 22, an X-axis second slider 23, a pair of left and right X-axis linear motors 26 and 26, and a pair of X-axis common support bases 24 and 24. .

  A workpiece mounting table 21 is attached to the X-axis first slider 22. The X-axis first slider 22 is supported by an X-axis common support base 24 extending in the X-axis direction so as to be slidable in the X-axis direction. An inspection drawing unit 161, a weight measurement unit 19, and a flushing unit 14 are attached to the X-axis second slider 23. The X-axis second slider 23 is supported by an X-axis common support base 24 extending in the X-axis direction so as to be slidable in the X-axis direction. The X-axis linear motor 26 is arranged in parallel with the X-axis common support base 24, and moves the X-axis first slider 22 or the X-axis second slider 23 along the X-axis common support base 24. The placing table 21 (work W placed on the workpiece placing table 21) or the weight measuring unit 19 is moved in the X-axis direction. The X-axis first slider 22 and the X-axis second slider 23 can be individually driven by an X-axis linear motor 26. The X-axis direction corresponds to the main scanning direction, and the Y-axis direction corresponds to the sub-scanning direction.

  The work mounting table 21 includes a suction table 31 and a θ table 32. The suction table 31 holds and holds the work W placed thereon. The θ table 32 supports the suction table 31, and corrects the position of the workpiece W set on the suction table 31 in the θ direction around the Z axis perpendicular to the X axis direction and the Y axis direction, and the θ correction is completed. Maintain direction and hold. The θ table 32 has a θ drive motor 532 and is driven by the θ drive motor 532.

  The position of the workpiece mounting table 21 in FIG. 1 and FIG. 2 is a feeding / unloading material position for feeding and unloading the workpiece W, and when an unprocessed workpiece W is introduced (feeding) to the suction table 31. Or, when the processed workpiece W is collected (material removal), the suction table 31 is moved to this position. The workpiece W is carried in and out (replaced) with respect to the suction table 31 by a robot arm (not shown) at the supply / discharge material position. The alignment of the unprocessed workpiece W supplied to the suction table 31 is performed at the supply / discharge material position using the θ table 32 and the image recognition unit 80.

  The image recognition unit 80 has two alignment cameras 81 and a camera moving mechanism 82. The camera moving mechanism 82 is disposed on the X-axis support base 1 </ b> A so as to extend in the Y-axis direction and straddle the X-axis table 11. The alignment camera 81 is supported by a camera moving mechanism 82 via a camera holder (not shown) so as to be slidable in the Y-axis direction. The alignment camera 81 supported by the camera moving mechanism 82 faces the X-axis table 11 from above, and images each reference mark (alignment mark) of the work W placed on the work placing table 21 on the X-axis table 11. Can be recognized. The two alignment cameras 81 are independently moved in the Y-axis direction by a camera moving motor (not shown).

  Each alignment camera 81 cooperates with the movement of the work table 21 in the X-axis direction, and moves in the Y-axis direction by the camera moving mechanism 82 while the alignment marks of the various works W supplied by the robot arm described above. To recognize the position of various workpieces W. Based on the imaging result of the alignment camera 81, θ correction (alignment) of the workpiece W by the θ table 32 is performed.

  The Y-axis table 12 includes a pair of Y-axis sliders (not shown) and a pair of Y-axis linear motors (not shown). The pair of Y-axis linear motors are respectively installed on the pair of Y-axis support bases 7 and 7 and extend in the Y-axis direction. The pair of Y-axis sliders are slidably supported one by one on each of the pair of Y-axis support bases 7 and 7. The pair of Y-axis sliders, each composed of one Y-axis slider supported on each of the pair of Y-axis support bases 7, 7, has both bridge plates 52 to which the carriage unit 51 constituting the discharge unit 2 is fixed. I support it. The bridge plate 52 to which the carriage unit 51 constituting the discharge unit 2 is fixed is installed on the pair of Y-axis support bases 7 and 7 via a Y-axis slider that supports the bridge plate 52 with both ends.

  When the pair of Y-axis linear motors are driven (synchronously), the Y-axis sliders simultaneously translate in the Y-axis direction using the pair of Y-axis support bases 7 and 7 as a guide. As a result, the bridge plate 52 moves in the Y-axis direction, and the carriage unit 51 suspended from the bridge plate 52 moves in the Y-axis direction.

  The carriage unit 51 includes a head unit 54 (see FIG. 4) having a plurality of droplet ejection heads 17 and a carriage plate 53 (see FIG. 4) that supports the plurality of droplet ejection heads 17. The head unit 54 is supported so as to be movable up and down in the Z-axis direction via a head lifting mechanism (not shown).

(Droplet ejection head)
Next, the droplet discharge head 17 will be described with reference to FIG. FIG. 3 is a diagram illustrating the configuration of the droplet discharge head. 3A is an external perspective view of the droplet discharge head as viewed from the nozzle plate side, and FIG. 3B is a perspective cross-sectional view showing the structure around the pressure chamber of the droplet discharge head. FIG. 3C is a cross-sectional view showing the structure of the discharge nozzle portion of the droplet discharge head. The droplet discharge head 17 corresponds to the discharge unit.

  As shown in FIG. 3A, the droplet discharge head 17 is a so-called double-unit, and includes a liquid introduction part 71 having two connection needles 72 and 72 and a side of the liquid introduction part 71. A head substrate 73 that is continuous, a pump portion 75 that is continuous with the liquid introduction portion 71, and a nozzle plate 76 that is continuous with the pump portion 75 are provided. A pipe connection member is connected to each connection needle 72 of the liquid introduction part 71, a liquid supply tube is connected via the pipe connection member, and a liquid supply unit (not shown) connected to the liquid supply tube. Is supplied with functional fluid. A pair of head connectors (not shown) are mounted on the head substrate 73, and a flexible flat cable (FFC cable) is connected via the head connectors. The droplet discharge head 17 is connected to a discharge device control unit (not shown) via an FFC cable, and signals are exchanged via the FFC cable. The pump unit 75 and the nozzle plate 76 constitute a square head main body 74.

  A flange portion 79 is formed in a square flange shape on the base side of the pump unit 75, that is, the base side of the head main body 74 so as to receive the liquid introduction unit 71 and the head substrate 73. The flange portion 79 is formed with a pair of screw holes (female screws) 79 a for small screws for fixing the droplet discharge head 17. The droplet discharge head 17 is fixed to the head holding member by a head set screw that passes through the head holding member and is screwed into the screw hole 79a.

  Eight nozzle rows 78a are formed on the nozzle formation surface 76a of the nozzle plate 76. The nozzle rows 78a are formed of the discharge nozzles 78 that are formed on the nozzle plate 76 and discharge liquid droplets. The eight nozzle rows 78a are arranged in parallel with each other, and each nozzle row 78a is constituted by, for example, 180 (schematically illustrated) discharge nozzles 78 arranged at an equal pitch. . As described above, eight nozzle rows 78 a are arranged on the nozzle forming surface 76 a of the head main body 74.

  In a state where the droplet discharge head 17 is attached to the droplet discharge device 1, the nozzle row 78a extends in the Y-axis direction, and one nozzle pitch is, for example, 140 μm. At the same position in the X-axis direction, the liquid droplets discharged from the discharge nozzles 78 constituting each nozzle row 78a land on a straight line at equal intervals in the Y-axis direction by design. When the nozzle pitch of the discharge nozzles 78 in the nozzle row 78a is 140 μm, the center-to-center distance between the landing positions that are connected in a straight line is 70 μm in design.

As shown in FIGS. 3B and 3C, in the droplet discharge head 17, the pressure chamber plate 151 constituting the pump unit 75 is laminated on the nozzle plate 76, and the vibration plate 152 is disposed on the pressure chamber plate 151. Are stacked.
The pressure chamber plate 151 is formed with a liquid pool 155 that is always filled with the functional liquid supplied from the liquid introducing portion 71 via the liquid supply hole 153 of the vibration plate 152. The liquid pool 155 is a space surrounded by the diaphragm 152, the nozzle plate 76, and the wall of the pressure chamber plate 151. The pressure chamber plate 151 is formed with a pressure chamber 158 divided by a plurality of head partition walls 157. A space surrounded by the diaphragm 152, the nozzle plate 76, and the two head partition walls 157 is a pressure chamber 158.

  The pressure chambers 158 are provided corresponding to the discharge nozzles 78, and the number of pressure chambers 158 and the number of discharge nozzles 78 are the same. The functional fluid is supplied from the liquid pool 155 to the pressure chamber 158 via the supply port 156 located between the two head partition walls 157. A set of the head partition wall 157, the pressure chamber 158, the discharge nozzle 78, and the supply port 156 is arranged in a line along the liquid pool 155, and the discharge nozzles 78 arranged in a line form a nozzle line 78a. . Although not shown in FIG. 3B, the discharge nozzles 78 arranged in a line in a substantially symmetrical position with respect to the liquid pool 155 with respect to the nozzle row 78a including the discharge nozzles 78 shown in the figure are another nozzle. A row 78a is formed, and a set of the corresponding head partition wall 157, pressure chamber 158, and supply port 156 is arranged in one row.

One end of the piezoelectric element 159 is fixed to the portion of the diaphragm 152 that constitutes the pressure chamber 158. The other end of the piezoelectric element 159 is fixed to a base (not shown) that supports the entire droplet discharge head 17.
The piezoelectric element 159 has an active portion in which an electrode layer and a piezoelectric material are stacked. By applying a driving voltage to the electrode layer, the active portion is arranged in the longitudinal direction (the diaphragm 152 in FIG. 3B or 3C). Shrink in the thickness direction). By contracting the active portion, the diaphragm 152 to which one end of the piezoelectric element 159 is fixed receives a force that is pulled to the side opposite to the pressure chamber 158. When the diaphragm 152 is pulled to the opposite side to the pressure chamber 158, the diaphragm 152 is bent to the opposite side of the pressure chamber 158. Thereby, since the volume of the pressure chamber 158 increases, the functional liquid is supplied from the liquid pool 155 to the pressure chamber 158 through the supply port 156. Next, when the driving voltage applied to the electrode layer is released, the active portion returns to the original length, and the piezoelectric element 159 presses the diaphragm 152. When the diaphragm 152 is pressed, it returns to the pressure chamber 158 side. As a result, the volume of the pressure chamber 158 suddenly returns to the original, that is, the increased volume is reduced, so that pressure is applied to the functional liquid filled in the pressure chamber 158, and the pressure chamber 158 communicates with the pressure chamber 158. The functional liquid is discharged as droplets from the discharge nozzle 78 formed in this manner. The liquid pool 155, the supply port 156, the pressure chamber 158, and the like through which the functional liquid flows correspond to the functional liquid flow path.

  The discharge device control unit (not shown) controls the discharge of the functional liquid to each of the plurality of discharge nozzles 78 by controlling the voltage applied to the piezoelectric element 159, that is, by controlling the drive signal. More specifically, the volume of droplets ejected from the ejection nozzle 78, the number of droplets ejected per unit time, and the like can be changed. This makes it possible to change the distance between the droplets that have landed on the substrate, the amount of the functional liquid to land on a certain area on the substrate, and the like. For example, by selectively using a discharge nozzle 78 that discharges droplets from among a plurality of discharge nozzles 78 arranged in the nozzle row 78a, the range of the length of the nozzle row 78a in the extending direction of the nozzle row 78a. In this case, a plurality of droplets can be discharged simultaneously at the pitch interval of the discharge nozzles 78. In a direction substantially orthogonal to the extending direction of the nozzle row 78a, the substrate and the discharge nozzle 78 are moved relative to each other, and the discharge nozzle 78 is disposed at an arbitrary position on the substrate where the discharge nozzle 78 can face in the relative movement direction. It is possible to arrange liquid droplets discharged from the liquid crystal. In addition, the volume of the droplet discharged from each of the discharge nozzles 78 is variable between 1 pl and 300 pl (picoliter), for example.

(Head unit)
Next, a schematic configuration of the head unit 54 provided in the discharge unit 2 will be described with reference to FIG. FIG. 4 is a view as seen from the nozzle plate 76 (nozzle forming surface 76a) side. The X axis and the Y axis shown in FIG. 4 coincide with the X axis and the Y axis shown in FIG. 1 when the head unit 54 is attached to the droplet discharge device 1.

  As shown in FIG. 4, the head unit 54 has a carriage plate 53 and 16 droplet discharge heads 17 mounted on the carriage plate 53. The droplet discharge head 17 is fixed to the carriage plate 53 via a head holding member 59, and the head main body 74 is loosely fitted in a hole (not shown) formed in the carriage plate 53, so that a nozzle plate 76 (head A main body 74) protrudes from the surface of the carriage plate 53.

  Four droplet discharge heads 17 are attached to each head holding member 59. As a result, the head unit 54 employs a configuration including first to fourth head sets 55, 56, 57, 58 each having four droplet discharge heads 17. The nozzle row 78a of each droplet discharge head 17 in each head set 55 to 58 extends in the Y-axis direction.

  The droplet discharge heads 17 of the first to fourth head groups 55, 56, 57, and 58 are configured to discharge functional liquids (inks) of different colors. Specifically, the droplet discharge head 17 of the first head set 55 discharges a cyan functional liquid onto the workpiece W. Further, the droplet discharge head 17 of the second head set 56 discharges yellow functional liquid onto the workpiece W. Further, the droplet discharge head 17 of the third head set 57 discharges the black functional liquid to the workpiece W. Further, the droplet discharge head 17 of the fourth head set 58 discharges a magenta functional liquid to the workpiece W.

  Based on the above configuration, the carriage plate 53 is provided with two head rows 17a and 17b in which a plurality of droplet discharge heads 17 are arranged along the Y direction. The droplet discharge heads 17 of the adjacent head rows 17a and 17b in the same head set are positioned so as to be shifted by half the head arrangement pitch in the Y direction.

  According to this, the droplets ejected from the ejection nozzles 78 of the droplet ejection heads 17 of the same head set are arranged at equal intervals in the Y-axis direction at the same position in the X-axis direction. It will land on the line. That is, droplets of the functional liquid of the same color can be landed on the work W at a fine pitch, and a fine drawing pattern can be formed on the work W.

  By the way, in the head unit 54 according to the present embodiment, since the plurality of droplet discharge heads 17 are arranged close to each other, the temperature is higher than that of the outer peripheral portion due to heat generated inside. Then, the viscosity of the functional liquid discharged from the droplet discharge head 17 changes, and there is a possibility that the functional liquid cannot be stably discharged from the discharge nozzle 78.

  On the other hand, in the present embodiment, the droplet discharge head 17 that discharges a type of functional liquid having a small viscosity change with respect to a predetermined temperature change is disposed inside the head unit 54 (carriage plate 53), and the viscosity change is large. The droplet discharge head 17 that discharges the functional liquid is disposed outside the head unit 54.

  Here, the predetermined temperature fluctuation means a temperature difference (temperature fluctuation) generated between the inside and the outside of the carriage plate 53 when the normal operation of discharging the functional liquid from the head unit 54 to the workpiece W is performed. To do. The type of functional liquid that has a small change in viscosity with respect to temperature fluctuation means a type of functional liquid that has a small change in discharge rate due to temperature fluctuation.

  Specifically, the functional liquid (yellow color and black color) discharged from the respective droplet discharge heads 17 of the second head set 56 and the third head set 57 arranged inside the head unit 54 is less affected by temperature fluctuations. Therefore, high quality drawing can be performed on the workpiece W.

  On the other hand, the functional liquid (cyan and magenta) discharged from the respective droplet discharge heads 17 of the first head set 55 and the fourth head set 58 disposed outside the head unit 54 is a droplet disposed inside. Compared with the functional liquid ejected from the ejection head 17, the influence of temperature fluctuation is greater.

  Here, since the first head set 55 and the fourth head set 58 arranged on the outer peripheral side of the head unit 54 are easily cooled by touching the outside air when the head unit 54 is moved, the liquid droplet ejection head is compared with the inside. The temperature rise of 17 is difficult. Therefore, by increasing the cooling efficiency of the droplet discharge head 17 itself that discharges the functional liquid that is easily affected by temperature fluctuations, as a result, the balance of thermal fluctuations of the droplet discharge head 17 between the inside and outside of the head unit 54 is balanced. The temperature of the entire head unit 54 can be made uniform.

  As described above, according to the droplet discharge device 1 according to the present embodiment, the droplet discharge head 17 having a small influence on the temperature variation is arranged on the inner side, and the droplet discharge head 17 having a large influence on the temperature variation is removed from the outside air. Since the head unit 54 disposed outside is cooled by being touched, the temperature of the entire head unit 54 is made uniform, and high-quality drawing can be performed on the workpiece W.

(Second Embodiment)
Next, the droplet discharge device according to the second embodiment will be described. The difference between the present embodiment and the first embodiment is the configuration of the droplet discharge head 117 in the head unit 154, and the other configurations are the same. Therefore, in the following description, the same members and configurations as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

  Unlike the first embodiment, each of the liquid droplet ejection heads 117 according to this embodiment is configured to eject functional liquids of four colors (cyan, yellow, black, and magenta). That is, each of the droplet discharge heads 117 of the first to fourth head groups 55, 56, 57, and 58 is configured to discharge the four color functional liquids as described above.

  FIG. 5 is an enlarged view of a main part of the droplet discharge head 117 of the head unit 54 according to the present embodiment as viewed from the nozzle plate 176 (nozzle forming surface 176a) side. In FIG. 5, the configuration of the first head set 55 is illustrated as an example and enlarged.

  As shown in FIG. 5, eight nozzle rows 178a, 178b, 178c, 178d, 178e, 178f, 178g, and 178h are formed on the nozzle forming surface 176a of each droplet discharge head 117. The cyan functional liquid is discharged to the workpiece W from the discharge nozzles 178 of the nozzle rows 178a and 178b. In addition, the yellow functional liquid is discharged to the workpiece W from the discharge nozzles 178 of the nozzle rows 178c and 178d. Further, the black functional liquid is discharged to the workpiece W from the discharge nozzles 178 of the nozzle rows 178e and 178f. Further, the magenta functional liquid is discharged to the workpiece W from the discharge nozzles 178 of the nozzle rows 178g and 178h.

  By the way, also in the head unit 154 according to the present embodiment, since the plurality of droplet discharge heads 117 are arranged close to each other, the heat is generated in the central portion (inner side), and the temperature becomes higher than that in the outer peripheral portion. It is possible.

  On the other hand, in the present embodiment, the nozzle rows 178c, 178d, 178e, 178f that discharge a type of functional liquid that has a small viscosity change with respect to a predetermined temperature change are arranged inside the nozzle formation surface 176a of the droplet discharge head 117. In addition, the nozzle rows 178a, 178b, 178g, and 178h for discharging the functional liquid having a large viscosity change are arranged outside the nozzle forming surface 176a of the droplet discharge head 117.

According to this, since the nozzle rows 178c, 178d, 178e, and 178f that discharge the functional liquid that has a small influence on the temperature fluctuation are arranged inside the nozzle formation surface 176a that easily generates heat, the influence of the temperature fluctuation is reduced. can do. In addition, the nozzle rows 178a, 178b, 178g, and 178h for discharging the functional liquid that is greatly affected by temperature fluctuations are disposed outside the nozzle forming surface 176a. Therefore, these nozzle rows 178a, 178b, 178g, and 178h are less likely to rise in temperature than the inside of the nozzle forming surface 176a by touching the outside air, and the influence of temperature fluctuation can be suppressed.
Therefore, also in this embodiment, the temperature of the entire droplet discharge head 117 can be made uniform by suppressing the influence of temperature fluctuations inside and outside the nozzle formation surface 176a. Thereby, the temperature of the head unit 154 itself including the plurality of droplet discharge heads 117 is made uniform, so that high quality drawing can be performed on the workpiece W.

(Third embodiment)
Subsequently, a droplet discharge device according to a third embodiment will be described. The difference between the present embodiment and the first embodiment is a reference for determining the arrangement of the droplet discharge heads 17 in the head unit 54, and other configurations are common. Therefore, a description is omitted in the present embodiment, and the description will be made with reference to FIG. 4 described in the first embodiment.

In the first embodiment, the droplet discharge head 17 that discharges a functional liquid having a large viscosity change is disposed outside the head unit 54 based on the viscosity change with respect to the temperature variation of the functional liquid discharged from the droplet discharge head 17, and the viscosity is increased. The droplet discharge head 17 that discharges a functional liquid with a small change is disposed inside the head unit 54.
In contrast, the head unit 54 according to this embodiment is different from the first embodiment in that the droplet discharge head 17 that discharges a type of functional liquid whose discharge amount is smaller than a predetermined reference is disposed inside the head unit 54. In addition, the liquid droplet ejection head 17 that ejects the functional liquid of a large amount of ejection is arranged outside the head unit 54.

  Here, the droplet discharge head 17 that discharges a functional liquid whose discharge amount is smaller than a predetermined reference means that the vibration of the piezoelectric element 159 is small when drawing on the workpiece W, and the droplet discharge head 17 itself This means the droplet discharge head 17 that has a small amount of heat generation and prevents the occurrence of problems such as heat generation even when densely arranged in the center (inner side) of the head unit 54.

In this embodiment, when drawing on the workpiece W, a relatively large amount of cyan and magenta functional liquids are discharged, and a relatively small amount of yellow and black functional liquids are discharged.
In this case, the head unit 54 has a second head set 56 for discharging a yellow functional liquid and a third head set 57 for discharging a black functional liquid disposed inside the head unit 54. In the head unit 54, a first head set 55 that discharges cyan functional liquid and a fourth head set 58 that discharges magenta functional liquid are disposed inside the head unit 54.

As described above, according to the present embodiment, the droplet discharge of each of the second head set 56 and the third head set 57 is less generated due to the relatively small discharge amount of the functional liquid so that the piezoelectric element 159 generates less heat during driving. Since the head 17 is disposed inside the head unit 54, the influence of temperature fluctuation can be reduced.
In addition, the droplet discharge heads 17 of the first head set 55 and the fourth head set 58 that generate a large amount of functional liquid and generate a lot of heat during driving are cooled by being exposed to the outside air, and the temperature rises compared to the inside. Since it is arranged outside the hard head unit 54, the influence of temperature fluctuation is reduced.
Therefore, the temperature of the entire head unit 54 can be made uniform by suppressing the influence of temperature fluctuations of the droplet discharge head 17 inside and outside the head unit 54.

(Fourth embodiment)
Subsequently, a droplet discharge device according to a fourth embodiment liquid will be described. The difference between the present embodiment and the second embodiment is a reference for determining the arrangement of the nozzle rows of the droplet discharge head 17 in the head unit 54, and the other configurations are common. Therefore, in the present embodiment, the description is omitted, and the description will be made with reference to FIG. 3 described in the second embodiment.

In the second embodiment, nozzle rows 178c, 178d, 178e, and 178f that discharge functional liquids of a type whose viscosity change is small with respect to a predetermined temperature change are arranged inside the nozzle formation surface 176a of the droplet discharge head 17, and the viscosity change Nozzle rows 178a, 178b, 178g, and 178h for discharging a functional liquid having a large size are arranged outside the nozzle formation surface 176a of the droplet discharge head 17.
On the other hand, unlike the second embodiment, the head unit 54 according to the present embodiment arranges a nozzle row that discharges a type of functional liquid whose amount is smaller than a predetermined reference inside the nozzle forming surface 176a, A nozzle row that discharges a type of functional liquid having a large discharge amount is arranged outside the nozzle forming surface 176a.

In this embodiment, when drawing on the workpiece W, a relatively large amount of cyan and magenta functional liquids are discharged, and a relatively small amount of yellow and black functional liquids are discharged.
In this case, the head unit 54 includes nozzle rows 178c and 178d having discharge nozzles 78 for discharging yellow functional liquid and nozzle rows 178e and 178f having discharge nozzles 78 for discharging black functional liquid. Place inside. Further, the head unit 54 includes nozzle rows 178a and 178b having discharge nozzles 78 for discharging cyan functional liquid and nozzle rows 178g and 178h having discharge nozzles 78 for discharging magenta functional liquid on the nozzle forming surface 176a. Place inside.

As described above, according to this embodiment, the nozzle rows 178c, 178d, 178e, and 178f, which generate a small amount of heat when the piezoelectric element 159 is driven due to a small discharge amount of the functional liquid, are arranged inside the nozzle formation surface 176a. Therefore, the influence of temperature fluctuation can be reduced.
In addition, the nozzle rows 178a, 178b, 178g, and 178h, which have a large discharge amount of functional liquid and a large amount of heat, are arranged outside the nozzle forming surface 176a, which is hard to rise in temperature compared to the inside due to being cooled by outside air. The effect of temperature fluctuation is reduced.
Therefore, the temperature of the entire droplet discharge head 17 can be made uniform by suppressing the influence of temperature fluctuations inside and outside the nozzle formation surface 176a. Thereby, the temperature of the head unit 54 itself including the plurality of droplet discharge heads 17 is made uniform, so that high-quality drawing can be performed on the workpiece W.

(Fifth embodiment)
Subsequently, a droplet discharge device according to a fifth embodiment will be described. The difference between the present embodiment and the above embodiment is the arrangement of the droplet discharge heads 17 in the head unit 254, and the other configurations are common. Therefore, in the following description, the same members and configurations as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

  FIG. 6 is an enlarged view of a main part of the head unit 254 according to the present embodiment as viewed from the nozzle plate 276 (nozzle formation surface 276a) side. As shown in FIG. 6, the head unit 254 according to the present embodiment is configured so that the number of droplet discharge heads 217 is larger on the inner side than on the outer side of the head unit 254. In the present embodiment, as in the second embodiment, each droplet discharge head 217 has eight nozzle rows 178a to 178h, and different colors (cyan, magenta) from the discharge nozzles 78 of the nozzle rows 178a to 178h. Color, yellow color, and black color) functional liquid.

  According to this configuration, since a relatively large number of droplet discharge heads 217 are arranged inside the head unit 254, the operating rate of each droplet discharge head 17 on the inside can be suppressed during the drawing process on the workpiece W. As a result, the amount of heat generated inside the head unit 254 is reduced, and the occurrence of temperature fluctuations can be suppressed.

Further, outside the head unit 254, since the number of droplet discharge heads 217 arranged is relatively small, the operating rate of each droplet discharge head 217 is increased and the amount of heat generation is increased. On the other hand, since the outside of the head unit 254 is cooled by touching the outside air and the temperature does not rise easily compared to the inside of the head unit 254, the occurrence of temperature fluctuation is suppressed.
Therefore, the temperature of the entire head unit 254 can be made uniform by suppressing the influence of the droplet discharge head 217 inside and outside the head unit 254.

(Sixth embodiment)
Subsequently, a droplet discharge device according to a sixth embodiment will be described. The difference between the present embodiment and the above embodiment is the configuration of the nozzle row in the droplet discharge head, and the other configurations are common. Therefore, in the following description, the same members and configurations as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

  FIG. 7 is an enlarged view of a main part of the head unit 354 according to the present embodiment as viewed from the nozzle plate 376 (nozzle forming surface 376a) side. As shown in FIG. 7, the droplet discharge head 317 according to the present embodiment has a larger number of nozzle rows when arranged on the inner side than that arranged on the outer side of the nozzle forming surface 376 a. ing. Specifically, the droplet discharge head 317 disposed on the outermost side of the nozzle forming surface 376a has two nozzle rows 378a and 378b, and the droplet disposed on the inner side of one of the nozzle forming surfaces 376a adjacent thereto. The discharge head 317 has four nozzle rows 378a, 378b, 378c, and 378d, and the droplet discharge head 317 disposed in the center of the nozzle forming surface 376a has eight nozzle rows 378a, 378b, 378c, 378d, 378e, 378f, 378g, and 378h.

  According to this configuration, in each droplet discharge head 317, since a relatively large number of nozzle rows are arranged inside the nozzle formation surface 376a, the operation rate of each discharge nozzle 378 can be suppressed, and as a result. The amount of heat generated inside the nozzle forming surface 376a is reduced, and the occurrence of temperature fluctuations can be suppressed.

  Further, outside the nozzle forming surface 376a, the number of nozzle rows arranged is relatively reduced, so that the operation rate of each discharge nozzle 378 is increased and the amount of heat generation is increased. On the other hand, since the outside of the nozzle forming surface 376a is cooled by touching the outside air and the temperature does not rise easily compared to the inside of the nozzle forming surface 376a, the occurrence of temperature fluctuation is suppressed. Therefore, a head unit including a plurality of droplet discharge heads 317 by suppressing temperature fluctuations inside and outside the nozzle forming surface 376a in each droplet discharge head 317 to make the temperature of the entire droplet discharge head 317 uniform. By making the temperature of the entire 354 uniform, good drawing processing can be performed on the workpiece W.

  DESCRIPTION OF SYMBOLS 1 ... Droplet discharge device, 17, 117, 217, 317 ... Droplet discharge head, 54, 154, 254, 354 ... Head unit, 76a, 176a, 276a, 376a ... Nozzle formation surface, 78a, 178a to 178h, 378a ~ 378h ... Nozzle row

Claims (8)

In a droplet ejection apparatus having a head unit in which a plurality of droplet ejection heads that eject liquid droplets onto a medium are arranged,
Each of the droplet discharge heads discharges the different liquid onto the medium,
In the head unit, the droplet discharge head that discharges the liquid of a type that has a small viscosity change with respect to a predetermined temperature change is disposed inside the head unit, and the viscosity change with respect to the predetermined temperature change has a large type. A liquid droplet ejection apparatus, wherein the liquid droplet ejection head for ejecting liquid is disposed outside the head unit. In a droplet discharge device having a droplet discharge head for discharging a liquid droplet onto a medium,
The droplet discharge head has a nozzle forming surface on which a plurality of nozzle rows are formed,
In the plurality of nozzle rows, a nozzle row for discharging the liquid of a type having a small viscosity change with respect to a predetermined temperature change is disposed inside the nozzle forming surface, and the type of the liquid having a large viscosity change with respect to the predetermined temperature change. A droplet ejection apparatus, wherein a nozzle row for ejecting is disposed outside the nozzle formation surface.   The droplet discharge device according to claim 2, further comprising a head unit including a plurality of the droplet discharge heads. In a droplet ejection apparatus having a head unit in which a plurality of droplet ejection heads that eject liquid droplets onto a medium are arranged,
Each of the droplet discharge heads discharges the different liquid onto the medium,
In the head unit, the droplet discharge head that discharges the type of liquid whose amount is smaller than a predetermined reference is disposed inside the head unit, and the type of the discharge amount that is higher than the predetermined reference is A liquid droplet ejection apparatus, wherein the liquid droplet ejection head for ejecting liquid is disposed outside the head unit. In a droplet discharge device having a droplet discharge head for discharging a liquid droplet onto a medium,
The droplet discharge head has a nozzle forming surface on which a plurality of nozzle rows are formed,
In the plurality of nozzle rows, a nozzle row for discharging the liquid of a type whose discharge amount is smaller than a predetermined reference is disposed inside the nozzle formation surface of the droplet discharge head, and the discharge amount is lower than the predetermined reference. 2. A droplet discharge device, wherein a plurality of types of nozzle rows for discharging the liquid are arranged outside the nozzle formation surface.   The liquid droplet ejection apparatus according to claim 5, comprising a plurality of the liquid droplet ejection heads. In a droplet ejection apparatus having a head unit in which a plurality of droplet ejection heads that eject liquid droplets onto a medium are arranged,
In the head unit, the liquid droplet ejection apparatus is arranged so that the number of the liquid droplet ejection heads is larger on the inner side than on the outer side of the head unit. In a droplet discharge device having a droplet discharge head that discharges liquid droplets from each nozzle of a plurality of nozzle rows to a medium,
In the liquid droplet ejection head, the liquid droplet ejection apparatus is characterized in that a larger number of the nozzle rows are arranged on the inner side with respect to the outer side of the nozzle forming surface on which the nozzles are formed.

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