JP2011161342A - Droplet ejection method, method of manufacturing color filter, and droplet ejection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a droplet ejection method capable of finely adjusting, for each area, the amount of a functional liquid to be applied onto a plurality of areas. <P>SOLUTION: The invention relates to a droplet ejection method whereby droplets 29 are ejected multiple times onto a first application area 37 disposed on a substrate, which method comprises setting an ejection target value, namely the target value of the total amount of the droplets 29 to be ejected onto the first application area 37, and ejecting the droplets 29 under an ejection condition wherein the value of an integer multiple of the ejection amount comes close to the ejection target value, which ejection condition is selected from a plurality of ejection conditions each different in terms of the ejection amount, i.e. the amount of the droplets 29. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a droplet discharge method, and more particularly to a method of applying a functional liquid to a plurality of regions having different areas.

  A method of forming a film by applying an ink jet method in which a functional liquid is discharged as droplets and solidifying the applied functional liquid is widely used. As the functional liquid, various kinds of liquid materials such as a liquid material having a function of coloring by including a dye or a pigment and a liquid material having a function of forming metal wiring by including metal particles are used.

  In the production of the color filter, a functional liquid that colors the regions partitioned in a matrix is applied. At this time, in order to improve the quality of the color tone of light transmitted through the color filter, it is necessary to apply the amount of the functional liquid with high quality.

  Patent Document 1 discloses a droplet discharge device that applies a functional liquid to a substrate using an inkjet method. The droplet discharge device includes a droplet discharge head, and a plurality of nozzles that discharge droplets are formed in the droplet discharge head. The droplet discharge head is provided with a cavity communicating with each nozzle and a vibrator for increasing / decreasing the volume of the cavity. The vibrator increases or decreases the volume of the cavity, so that the liquid filled in the cavity is discharged as a droplet from the nozzle.

  The droplet discharge device includes a workpiece moving mechanism that moves a workpiece and a head moving mechanism that moves a droplet discharge head. The workpiece and the droplet discharge head move in a direction orthogonal to each other. Then, when the droplet discharge head is located at a location opposite to the location where the functional liquid is applied, the droplet is discharged from the droplet discharge head. Thus, a predetermined pattern is drawn on the work by causing the droplet to land at a predetermined position.

JP 2008-94044 A

  By forming a plurality of types of color filters on a single substrate, a plurality of types of color filters can be manufactured simultaneously. As a result, a required type of color filter can be manufactured quickly. In the color filter, the size of each pixel, which is a colored region, is different for each type. Therefore, it is necessary to apply a predetermined amount of functional liquid to each region having a different width. The amount of the functional liquid applied to this region is an amount obtained by multiplying the amount of droplets and the number of ejections. Conventionally, the number of droplets to be discharged is one. The adjustment of the amount of the functional liquid to be applied was selected from an amount that is an integral multiple of the amount of droplets. Therefore, there has been a demand for a droplet discharge method capable of finely adjusting the amount of the functional liquid to be applied for each region where the functional liquid is applied.

  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]
The droplet discharge method according to this application example is a droplet discharge method in which droplets are discharged a plurality of times toward a film formation region provided on a substrate, and the total amount of the droplets to be discharged to the film formation region The discharge condition in which a value obtained by multiplying the discharge amount by an integer is close to the discharge target value among a plurality of discharge conditions having different discharge amounts as the droplet amount with respect to the discharge target value as the target value of The liquid droplets are selected and discharged.

  According to this droplet discharge method, a film formation region is provided on the base material, and a discharge target value of a droplet to be discharged is set in this film formation region. Then, a predetermined discharge amount of droplets is discharged a plurality of times toward the film formation region. A plurality of discharge conditions are prepared for discharging droplets, and the discharge amount changes when the discharge conditions are changed. A droplet is discharged using one discharge condition among a plurality of discharge conditions. The total amount of droplets discharged to the film formation region is an amount obtained by multiplying the discharge amount discharged at one time by the number of discharges. Then, a discharge condition capable of reducing the difference between the total amount of discharged liquid droplets and the discharge target value is selected, and the liquid droplets are discharged using the discharge conditions. Accordingly, it is possible to eject a droplet having an amount close to the ejection target value in the film formation region.

[Application Example 2]
In the droplet discharge method according to the application example, the plurality of discharge conditions include the discharge condition in which a value obtained by multiplying the discharge amount by an integer is the discharge target value.

  According to this droplet discharge method, discharge conditions are prepared in which the total amount of droplets discharged to the film formation region is equal to the discharge target value. Therefore, by using this discharge condition, it is possible to discharge the same amount of droplets as the discharge target value in the film formation region.

[Application Example 3]
In the droplet discharge method according to the application example, the base material includes a plurality of types of film formation regions having different discharge target values, and the droplets are used under the discharge conditions selected for each type of the film formation region. It is characterized by discharging.

  According to this droplet discharge method, the substrate has a plurality of types of film formation regions having different discharge target values. Then, a discharge condition with a small difference between the total amount of liquid droplets to be discharged and a discharge target value is selected for each type of film formation region, and the liquid droplets are discharged using the discharge conditions. Accordingly, it is possible to discharge a droplet having an amount close to the target discharge value in each film formation region.

[Application Example 4]
In the droplet discharge method according to the application example described above, a drive element provided for each nozzle is driven by a drive waveform that is an electrical signal so that the droplet is discharged from the nozzle, and the drive waveform is changed when the discharge condition is switched. It is characterized by switching.

  According to this droplet discharge method, the drive element is driven by an electrical signal. Then, the driving condition of the element is switched by switching the driving waveform. Switching the driving waveform can be easily switched by a simple electric circuit, so that the element driving conditions can be switched by a simple device.

[Application Example 5]
In the droplet discharge method according to the application example, the drive element is an element whose discharge amount changes according to an applied voltage, and the drive waveform is a waveform maintained at a predetermined drive voltage in a predetermined section. The drive voltage of the drive waveform is switched when the discharge condition is switched.

  According to this droplet discharge method, the discharge conditions are switched by switching the drive voltage of the drive waveform. Since the voltage can be switched by a simple electric circuit, it can be controlled by a simple device.

[Application Example 6]
In the droplet discharge method according to the application example, the droplet is discharged from the nozzle while relatively moving the base material and the nozzle, and the base material and the nozzle are relatively moved when the discharge condition is switched. It is performed between.

  According to this droplet discharge method, the discharge conditions are switched while the base material and the nozzle are relatively moved. That is, the ejection condition is switched while moving from one film formation region to another film formation region. Therefore, it is possible to discharge the droplets with higher productivity than in the case where the relative movement between the base material and the nozzle and the switching of the discharge conditions are successively performed.

[Application Example 7]
The color filter manufacturing method according to this application example is a method of manufacturing a color filter having a colored film in a plurality of film forming regions partitioned on a substrate, and the total amount of droplets discharged to the film forming region A discharge target value that is a target value of the liquid droplet is set, and a value obtained by multiplying the discharge amount by an integer among a plurality of discharge conditions having different discharge amounts that are the amount of droplets is close to the discharge target value. And discharging the droplets.

  According to this method for manufacturing a color filter, a film formation region is provided on a base material, and a discharge target value for droplets discharged to the film formation region is set. Then, a predetermined discharge amount of droplets is discharged a plurality of times toward the film formation region. A plurality of discharge conditions are prepared for discharging droplets, and the discharge amount changes when the discharge conditions are changed. A droplet is discharged using one discharge condition of a plurality of discharge conditions. The total amount of droplets discharged to the film formation region is an amount obtained by multiplying the discharge amount discharged at one time by the number of discharges. Then, a discharge condition capable of reducing the difference between the total amount of discharged liquid droplets and the discharge target value is selected, and the liquid droplets are discharged using this discharge condition. Accordingly, it is possible to discharge a droplet having an amount close to the discharge target value to the film formation region. As a result, the colored film can be formed with good quality.

[Application Example 8]
The liquid droplet ejection apparatus according to this application example is a liquid droplet ejection apparatus that ejects liquid droplets a plurality of times toward a film formation region provided on a substrate, and stores a plurality of ejection conditions with different ejection amounts. A value obtained by multiplying the discharge amount by an integer among the discharge conditions is close to the discharge target value with respect to a discharge target value that is a target value of the total amount of the droplets discharged to the film forming region. And a discharge condition setting unit that selects the discharge condition, and a discharge unit that discharges the droplets under the discharge condition selected by the discharge condition setting unit.

  According to this droplet discharge device, a film formation region is provided on the base material, and a discharge target value for droplets discharged to the film formation region is set. Then, a predetermined discharge amount of droplets is discharged a plurality of times toward the film formation region. A plurality of discharge conditions are stored in the storage unit when the droplets are discharged. When changing the discharge conditions, the discharge amount changes. The ejection unit ejects droplets using one ejection condition among a plurality of ejection conditions. The total amount of droplets discharged to the film formation region is an amount obtained by multiplying the discharge amount discharged at one time by the number of discharges. The ejection condition setting unit selects ejection conditions that can reduce the difference between the total amount of ejected droplets and the ejection target value, and the ejection unit ejects droplets using the ejection conditions. Therefore, this droplet discharge device can discharge a quantity of droplets close to the discharge target value in the film formation region.

In connection with the first embodiment, (a) is a schematic plan view showing a color filter, and (b) is a schematic sectional view of the color filter. (A) is a schematic perspective view showing the configuration of the droplet discharge device, (b) is a schematic plan view showing the arrangement of the droplet discharge head, and (c) is a diagram for explaining the structure of the droplet discharge head FIG. (A) is a schematic cross section which shows a discharge amount measuring apparatus, (b) is a schematic top view which shows the board | substrate arrange | positioned on a mounting surface. The electric control block diagram of a droplet discharge device. (A) is an electric control block diagram of a droplet discharge head, (b) is a time chart showing a drive waveform. The flowchart which shows the manufacturing process which discharges a droplet to a board | substrate and manufactures a color filter. The schematic diagram for demonstrating the drawing method using a droplet discharge apparatus. The schematic diagram for demonstrating the drawing method using a droplet discharge apparatus. The schematic diagram for demonstrating the drawing method using a droplet discharge apparatus. The time chart for demonstrating the drive waveform of the piezoelectric element in connection with 2nd Embodiment. The figure for demonstrating the discharge conditions concerning 3rd Embodiment.

  Hereinafter, specific embodiments will be described with reference to the drawings. In addition, each member in each drawing is illustrated with a different scale for each member in order to make the size recognizable on each drawing.

(First embodiment)
An example of a droplet discharge device according to the present embodiment and an example of a characteristic manufacturing method for forming a color filter by discharging droplets using the droplet discharge device will be described with reference to FIGS.

(Color filter)
First, the color filter 1 will be described with reference to FIG. FIG. 1A is a schematic plan view showing a color filter. FIG. 1B is a schematic cross-sectional view taken along the line AA ′ of the color filter of FIG. The color filter 1 is used in a display device such as a liquid crystal television, and forms a color image by allowing white light having a luminance distribution corresponding to an image signal to pass through the color filter 1. As shown in FIG. 1, the color filter 1 includes a substrate 2 as a base material. The substrate 2 is only required to be light transmissive and strong enough not to be broken by tension, and a glass plate, a plastic plate, a plastic sheet or the like can be used. In the present embodiment, for example, a glass plate is employed. On the upper surface of the substrate 2, the coloring elements 3 are formed so as to be arranged vertically and horizontally. The coloring elements 3 are composed of red, blue and green coloring elements 3, and the coloring elements 3 of each color are arranged and arranged for each column. In FIG. 1A, the colored elements 3 are arranged in the order of the red element row 3a, the blue element row 3b, and the green element row 3c from the top. And it arrange | positions in stripe form by repeating this order from the top to the bottom in the figure.

  The coloring element 3 includes a partition wall 4 formed in a lattice shape, and the partition wall 4 is formed of a colored resin material. This prevents light from passing through the partition 4. Colored films 5 such as a red colored film 5a, a blue colored film 5b, and a green colored film 5c are formed at locations partitioned by the partition 4 into rectangles. A red colored film 5a is formed on the colored elements 3 of the red element row 3a, and a blue colored film 5b and a green colored film 5c are formed on the blue element row 3b and the green element row 3c, respectively.

(Droplet discharge device)
Next, a droplet discharge device 6 that forms droplets on the substrate 2 to form the colored film 5 will be described with reference to FIG. There are various types of droplet discharge devices, but a device using an ink jet method is preferable. The ink jet method is suitable for microfabrication because it can discharge minute droplets.

  FIG. 2A is a schematic perspective view showing the configuration of the droplet discharge device. Droplets are ejected by the droplet ejection device 6. As shown in FIG. 2A, the droplet discharge device 6 includes a base 7 formed in a rectangular parallelepiped shape. In the present embodiment, the longitudinal direction of the base 7 is the Y direction, and the direction orthogonal to the Y direction on the horizontal plane is the X direction. The vertical direction is the Z direction. The direction in which the droplet discharge head and the object to be discharged move relative to each other when discharging droplets is defined as a main scanning direction. The direction orthogonal to the main scanning direction is defined as the sub scanning direction. The sub-scanning direction is a direction in which the droplet discharge head and the discharge target object move relative to each other when a line feed is made. In this embodiment, the Y direction is the main scanning direction, and the X direction is the sub scanning direction.

  On the upper surface 7a of the base 7, a pair of guide rails 8 extending in the Y direction are provided so as to protrude over the entire width in the Y direction. A stage 9 having a linear motion mechanism (not shown) corresponding to the pair of guide rails 8 is attached to the upper side of the base 7. As the linear motion mechanism of the stage 9, a mechanism such as a linear motor or a screw type linear motion mechanism can be used. In this embodiment, for example, a linear motor is employed. The stage 9 moves forward or backward along the Y direction at a predetermined speed. Repeating forward and backward movement is called scanning movement. Further, a main scanning position detection device 10 is disposed on the upper surface 7 a of the base 7 in parallel with the guide rail 8, and the position of the stage 9 is detected by the main scanning position detection device 10.

  A placement surface 11 is formed on the upper surface of the stage 9, and a suction-type substrate chuck mechanism (not shown) is provided on the placement surface 11. A substrate 2 is placed on the mounting surface 11, and the substrate 2 is fixed to the mounting surface 11 by a substrate chuck mechanism. A partition wall 4 is formed on the substrate 2.

  A pair of support bases 12 are erected on both sides in the X direction of the base 7, and a guide member 13 extending in the X direction is installed on the pair of support bases 12. On the upper side of the guide member 13, a storage tank 14 is installed for storing functional liquid to be discharged. The storage tank 14 stores a functional liquid containing a dye or a pigment.

  Under the guide member 13, a guide rail 15 extending in the X direction is installed over the entire width in the X direction. The carriage 16 attached so as to be movable along the guide rail 15 is formed in a substantially rectangular parallelepiped shape. The carriage 16 includes a linear motion mechanism. As the linear motion mechanism, for example, a mechanism similar to the linear motion mechanism included in the stage 9 can be used. Then, the carriage 16 scans and moves along the guide rail 15. A sub-scanning position detection device 17 is disposed between the guide member 13 and the carriage 16 to measure the position of the carriage 16. A head unit 18 is installed on the lower side of the carriage 16, and a droplet discharge head (not shown) is projected on the stage 9 side of the head unit 18.

  A discharge amount measuring device 19 is disposed on a side surface of the base 7 on the −X direction side and facing the guide member 13. The discharge amount measuring device 19 includes an electronic balance and has a function of measuring the weight of droplets discharged from the droplet discharge head.

  FIG. 2B is a schematic plan view showing the arrangement of the droplet discharge heads. As shown in FIG. 2B, in one head unit 18, droplet discharge heads 22 as three discharge units are arranged at equal intervals in the Y direction. Red, blue, and green functional liquids are supplied to the three droplet discharge heads 22. The droplet discharge heads 22 that discharge the functional liquids of the respective colors are arranged in a staggered manner in the X direction.

  A nozzle plate 23 is disposed on the surface of the droplet discharge head 22, and a plurality of nozzles 24 are formed on the nozzle plate 23. The number and arrangement of the nozzles 24 may be set according to the pattern to be ejected and the size of the substrate 2. In the present embodiment, for example, one nozzle plate 23 has an array of nozzles 24 formed in one row, and 15 nozzles 24 are arranged in each row.

  FIG. 2C is a schematic cross-sectional view of a main part for explaining the structure of the droplet discharge head. As shown in FIG. 2C, the droplet discharge head 22 includes a nozzle plate 23, and a nozzle 24 is formed on the nozzle plate 23. A cavity 25 as a pressure chamber communicating with the nozzle 24 is formed on the upper side of the nozzle plate 23 in the drawing and at a position facing the nozzle 24. A functional liquid 26 as a liquid material stored in the storage tank 14 is supplied to the cavity 25 of the droplet discharge head 22 via a flow path (not shown).

  Above the cavity 25, a vibration plate 27 that vibrates in the vertical direction (Z direction) and expands and contracts the volume in the cavity 25, and a piezoelectric element as a drive element that expands and contracts in the vertical direction to vibrate the vibration plate 27. 28 is disposed. When the droplet discharge head 22 receives an element drive signal for controlling and driving the piezoelectric element 28, the piezoelectric element 28 expands and contracts. Thereby, the diaphragm 27 pressurizes the cavity 25 by enlarging / reducing the volume in the cavity 25. As a result, the functional liquid 26 corresponding to the reduced volume is ejected as droplets 29 from the nozzles 24 of the droplet ejection head 22.

  FIG. 3A is a schematic cross-sectional view showing a discharge amount measuring apparatus. In FIG. 3A, the discharge amount measuring device 19 includes a base 30, and an exterior part 31 having a cavity therein is installed on the base 30. Three electronic balances 32 are arranged in the Y direction inside the exterior portion 31. A tray 33 is disposed on each electronic balance 32, and a sponge-like absorber 34 is installed on the Z direction side of the tray 33. The droplets 29 discharged from the droplet discharge head 22 to the tray 33 are prevented from jumping out of the tray 33. The droplets 29 that have landed on the receiving tray 33 are combined to form a liquid pool of the functional liquid 26, pass through the absorber 34, and are accumulated on the receiving tray 33. The electronic balance 32 measures the weight of the droplet 29 discharged to the receiving tray 33 and the receiving tray 33 before and after discharging the droplet 29 multiple times by the droplet discharging head 22. Then, by calculating the difference between the weights of the trays 33 before and after the discharge, the discharge amount measuring device 19 calculates the weight of the discharged droplets 29. Then, by dividing the calculated weight of the droplet 29 by the number of ejections, the ejection amount measuring device 19 can detect the weight of the droplet 29 in one ejection.

  FIG. 3B is a schematic plan view showing the substrate disposed on the placement surface. In FIG. 3B, two first patterns 35 and three second patterns 36 are formed on the substrate 2 by the partition walls 4. The first pattern 35 and the second pattern 36 are similar patterns, and the first pattern 35 is a figure obtained by enlarging the second pattern 36. In the first pattern 35, the region divided into the partition walls 4 is a first application region 37 as a film formation region, and in the second pattern 36, the region divided into the partition walls 4 is a second application region 38 as a film formation region. . The first application region 37 and the second application region 38 are places where the functional liquid 26 is applied by the droplet discharge device 6. The two first patterns 35 are arranged side by side in the X direction, and the three second patterns 36 are also arranged side by side in the X direction. The first pattern 35 and the second pattern 36 are arranged side by side in the Y direction, which is the main scanning direction. Therefore, when the substrate 2 moves in the main scanning direction, the first application region 37 and the second application region 38 are located in a place opposite to the droplet discharge head 22.

  A rectangular cutting planned line 39 is set so as to surround the first pattern 35 and the second pattern 36. The planned cutting line 39 is a line that forms the outer shape of the color filter 1. The substrate 2 becomes individual color filters 1 by being separated along the planned cutting line 39.

  FIG. 4 is an electric control block diagram of the droplet discharge device. As shown in FIG. 4, the droplet discharge device 6 includes a control device 41 as a control unit that controls the operation of the droplet discharge device 6. The control device 41 includes a CPU (Central Processing Unit) 42 that performs various arithmetic processes as a processor, and a memory 43 as a storage unit that stores various information.

  The main scanning drive device 44, the main scanning position detection device 10, the sub scanning drive device 45, and the sub scanning position detection device 17 are connected to the CPU 42 via the input / output interface 46 and the data bus 47. Further, a head drive circuit 48 that drives the droplet discharge head 22, a discharge amount measuring device 19, an input device 49, and a display device 50 are also connected to the CPU 42 via an input / output interface 46 and a data bus 47.

  The main scanning drive device 44 is a device that controls the movement of the stage 9, and the sub-scanning drive device 45 is a device that controls the movement of the carriage 16. The main scanning position detecting device 10 detects the position of the stage 9 and the main scanning driving device 44 drives the stage 9 so that the stage 9 can be moved and stopped to a desired position. Similarly, the sub-scanning position detecting device 17 detects the position of the carriage 16 and the sub-scanning driving device 45 drives the carriage 16 so that the carriage 16 can be moved and stopped at a desired position.

  The input device 49 is a device for inputting various processing conditions for ejecting the droplets 29. For example, the input device 49 is a device that receives and inputs coordinates for ejecting the droplets 29 onto the substrate 2 from an external device (not shown). The display device 50 is a device that displays processing conditions and work conditions, and an operator performs an operation using the input device 49 based on information displayed on the display device 50.

  The memory 43 is a concept including a semiconductor memory such as a RAM and a ROM, and an external storage device such as a hard disk and a DVD-ROM. Functionally, a storage area for storing the program software 51 in which the operation control procedure in the droplet discharge device 6 is described is set. Furthermore, a storage area for storing discharge position data 52, which is coordinate data of discharge positions discharged onto the substrate 2, is also set.

  In addition, a plurality of discharge conditions such as drive voltage data 53 which is data indicating the relationship between the drive waveform and the discharge amount when driving the droplet discharge head 22 and drive waveform data 54 which drives the droplet discharge head 22 are stored. A storage area is set. Further, a storage area is set for storing discharge plan data 55 that is drive voltage data at each discharge location. In addition, a work area for the CPU 42, a storage area that functions as a temporary file, and other types of storage areas are set.

  The CPU 42 performs control for ejecting the droplet 29 to a predetermined position on the substrate 2 according to the program software 51 stored in the memory 43. As a specific function realization unit, a drawing control unit 56 that performs control for discharging and drawing the droplet 29 from the droplet discharge head 22 is provided. If the drawing control unit 56 is divided in detail, the drawing control unit 56 has a main scanning control unit 57 that performs control for moving the stage 9 at a predetermined speed in the main scanning direction. In addition, the drawing control unit 56 includes a sub-scanning control unit 58 that performs control for moving the droplet discharge head 22 in the sub-scanning direction by a predetermined sub-scanning amount. Further, the drawing control unit 56 includes a discharge control unit 59 that controls which of the plurality of nozzles in the droplet discharge head 22 activates the droplet discharge head 22 to discharge the droplet 29, and the like. It has various arithmetic units and control units.

  In addition, it includes a discharge amount measurement control unit 60 that drives the droplet discharge head 22 and the discharge amount measuring device 19 to measure the weight of the droplet 29 discharged by the droplet discharge head 22. Furthermore, a discharge condition setting unit 61 is provided for setting the discharge amount and the number of discharges of the droplet 29 discharged from the nozzle 24 from the amount and discharge characteristics of the functional liquid 26 discharged to the first application region 37 and the second application region 38. In addition, a discharge plan setting unit 62 that sets the drive waveform of the piezoelectric element 28 at each location where the droplet 29 is discharged is provided.

  FIG. 5A is an electric control block diagram of the droplet discharge head. As shown in FIG. 5A, the droplet discharge head 22 is electrically connected to a head drive circuit 48, and the head drive circuit 48 is electrically connected to a control device 41. The head drive circuit 48 is a circuit that drives the droplet discharge head 22, and the control device 41 is a device that controls the operation of the droplet discharge device 6.

  The control device 41 outputs data relating to the nozzle 24 that ejects the functional liquid 26, drive signal data for driving the piezoelectric element 28 and ejection timing data, and the like to the head drive circuit 48. The head drive circuit 48 mainly includes a discharge control circuit 65, nine drive signal circuits 66, and a power supply circuit 67. The discharge control circuit 65 is electrically connected to the drive signal circuit 66 and the power supply circuit 67. Yes. Nine droplet discharge heads 22 are arranged in the head unit 18, and one drive signal circuit 66 and one power supply circuit 67 are arranged for one droplet discharge head 22. The number of the discharge control circuit 65, the drive signal circuit 66, and the power supply circuit 67 is not limited to this, and it is preferable to arrange an appropriate number according to the specifications of the apparatus.

  Data output from the control device 41 to the head drive circuit 48 is input to the ejection control circuit 65. The discharge control circuit 65 classifies the input data relating to the nozzle 24 and the drive signal data for each droplet discharge head 22. Then, the discharge control circuit 65 outputs the divided drive signal data and discharge timing data to the drive signal circuit 66, and outputs the divided drive voltage data to the power supply circuit 67. The drive signal circuit 66 forms a discharge waveform signal using the input data such as discharge waveform data and discharge timing data.

  The droplet discharge head 22 includes a distribution circuit 68 and a piezoelectric element 28, and the drive signal circuit 66 and the power supply circuit 67 are electrically connected to the distribution circuit 68. Further, the distribution circuit 68 is electrically connected to the piezoelectric element 28. The drive signal circuit 66 outputs a voltage signal having a drive waveform for driving the piezoelectric element 28 to the distribution circuit 68 in accordance with the timing of discharging the functional liquid 26. Further, the power supply circuit 67 outputs a supply voltage corresponding to the input drive voltage data to the distribution circuit 68.

  The distribution circuit 68 outputs a drive waveform to each piezoelectric element 28 using the input ejection waveform signal and supply voltage. Each piezoelectric element 28 receives a drive waveform, contracts in accordance with the drive waveform, and then expands. Thereby, the functional liquid 26 is discharged from the droplet discharge head 22.

  FIG. 5B is a time chart showing drive waveforms. In FIG.5 (b), a vertical axis | shaft shows a voltage and the upper side is a voltage higher than lower side. The horizontal axis shows the passage of time, and the time changes from left to right in the figure. An ejection waveform signal 69 indicates a signal output from the drive signal circuit 66 to the distribution circuit 68. The waveform of the discharge waveform signal 69 is formed in a trapezoidal shape. The discharge waveform signal 69 rises to a unit voltage and falls after maintaining a predetermined interval voltage. At the timing when the voltage rises, the piezoelectric element 28 contracts and the volume of the cavity 25 increases. At the timing when the voltage drops, the piezoelectric element 28 extends and the volume of the cavity 25 decreases. Accordingly, the functional liquid 26 flows into the cavity 25 at the timing when the voltage increases, and the droplet 29 is ejected at the timing when the voltage decreases. A substantially constant interval is maintained between the timing when the voltage rises and the timing when the voltage falls. Thereby, the discharge amount is controlled with good quality.

  A supply voltage waveform 70 shows a waveform of the supply voltage 71 output from the power supply circuit 67 to the distribution circuit 68. The first voltage 71 a, the second voltage 71 b, and the third voltage 71 c are examples of the supply voltage 71. In this example, the voltage decreases in the order of the first voltage 71a, the second voltage 71b, and the third voltage 71c. In the supply voltage waveform 70, the supply voltage 71 is switched before the timing when the discharge waveform signal 69 rises, and the supply voltage 71 is switched after the timing when the discharge waveform signal 69 falls.

  A drive waveform 72 is a waveform of a voltage output from the distribution circuit 68 to the piezoelectric element 28. The drive waveform 72 is formed by multiplying the ejection waveform signal 69 and the supply voltage waveform 70. Since the voltage of the ejection waveform signal 69 is a unit voltage, the voltage of the drive waveform 72 is the same voltage as the supply voltage waveform 70. The drive waveforms 72 when the supply voltage 71 is the first voltage 71a, the second voltage 71b, and the third voltage 71c are referred to as a first drive waveform 72a, a second drive waveform 72b, and a third drive waveform 72c, respectively. The voltage that the drive waveform 72 rises and is maintained for a predetermined period is referred to as a drive voltage 73. At this time, the first drive voltage 73a, which is the drive voltage 73 of the first drive waveform 72a, is the same voltage as the first voltage 71a. Similarly, the second drive voltage 73b, which is the drive voltage 73 of the second drive waveform 72b, is the same voltage as the second voltage 71b, and the third drive voltage 73c, which is the drive voltage 73 of the third drive waveform 72c, is the third voltage. It becomes the same voltage as 71c.

  The distribution circuit 68 outputs a voltage signal having a drive waveform 72 to the piezoelectric element 28. At this time, the distribution circuit 68 outputs a voltage signal of the drive waveform 72 only to the piezoelectric element 28 corresponding to the nozzle 24 that is to eject the droplet 29. The drive waveform 72 of the same supply voltage 71 is output to the piezoelectric element 28 in one droplet discharge head 22. Since the voltage of the supply voltage 71 of the supply voltage waveform 70 is switched for each discharge, the supply voltage 71 of the drive waveform 72 can be changed each time the discharge is performed.

(Drawing method)
Next, a drawing method for drawing by drawing on the substrate 2 from the droplet discharge head 22 using the above-described droplet discharge device 6 will be described with reference to FIGS. FIG. 6 is a flowchart showing a manufacturing process for manufacturing a color filter by discharging droplets onto a substrate. 7 to 9 are schematic diagrams for explaining a drawing method using a droplet discharge device.

  Step S1 corresponds to a discharge characteristic measuring step. In this step, droplets are ejected from the nozzle by changing the drive waveform for driving the piezoelectric element. And it is the process of measuring the quantity of the droplet discharged when a drive waveform is changed. Next, the process proceeds to step S2. Step S2 corresponds to a voltage-discharge position setting step. This step is a step of setting a drive waveform for driving the piezoelectric element for each position of the droplet discharge head on the substrate. Next, the process proceeds to step S3. Step S3 corresponds to a material supply process, and is a process of placing the substrate on the placement surface of the stage. Next, the process proceeds to step S4. Step S4 corresponds to a discharge condition setting step. In this step, a preset driving voltage of the piezoelectric element is set in the power supply circuit. Then, after the second and subsequent scanning movements, the stage is changed to change the stage moving direction. Next, the process proceeds to step S5. Step S5 corresponds to an ejection process, and is a process of ejecting droplets from the nozzle while moving the stage. Next, the process proceeds to step S6. Step S6 corresponds to an end determination step, and is a step for determining whether or not droplets have been discharged to all locations where droplets are to be discharged. Since there is a place which has not yet been discharged, the process proceeds to step S4 when the discharge is continued. Since the liquid droplets are discharged to all the planned locations, the process proceeds to step S7 when the discharge is finished. The process from step S4 to step S6 is combined into a drawing process of step S11. This step is a step of drawing a predetermined pattern on the substrate. Next, the process proceeds to step S7. Step S7 corresponds to a material removal process, which is a process of moving the substrate from the placement surface to the next process. Step S8 corresponds to a solidification step and is a step of solidifying the functional liquid applied to the substrate to form a film. Next, the process proceeds to step S9. Step S9 corresponds to a separation step, and is a step of cutting the substrate and dividing it into individual color filters. This completes the manufacturing process for manufacturing the color filter by discharging droplets onto the substrate.

  Next, a manufacturing method for manufacturing the color filter 1 by discharging the droplets 29 from the droplet discharge head 22 in correspondence with the steps shown in FIG. 6 will be described in detail with reference to FIGS. FIG. 7A and FIG. 7B are diagrams corresponding to the ejection characteristic measurement process in step S1. As shown in FIG. 7A, the ejection characteristics of the droplet ejection head 22 are measured in step S1. The discharge amount measurement control unit 60 sets the drive voltage 73 of the drive waveform 72 to a predetermined voltage. Then, the discharge amount measurement control unit 60 discharges the droplet 29 from the nozzle 24. Then, the discharge amount measurement control unit 60 detects the discharge amount that is the weight of the discharged droplet 29 by driving the discharge amount measuring device 19.

  Specifically, first, the discharge amount measurement control unit 60 causes the electronic balance 32 to measure the weight of the tray 33. Next, the discharge amount measurement control unit 60 drives the head drive circuit 48 to discharge from the nozzle 24 of the droplet discharge head 22 a predetermined number of times. At this time, a single droplet discharge head 22 discharges droplets 29 from all the nozzles 24 used in the drawing process of step S11. The number of nozzles 24 that eject the droplets 29 is defined as the number of ejection nozzles. The greater the number of ejections, the better the measurement accuracy, but the greater the amount of functional liquid 26 consumed. Therefore, the smaller the number of ejections, the better the required measurement accuracy. The number of discharges is not particularly limited, but is set to, for example, 1000 times in the present embodiment.

  After discharging the droplet 29, the discharge amount measurement control unit 60 causes the electronic balance 32 to measure the weight of the tray 33 again. And the difference of the weight of the saucer 33 before discharging the droplet 29 from the weight of the saucer 33 after discharging the droplet 29 is calculated. Thereafter, the amount of droplet 29 ejected once from one nozzle 24 is calculated by dividing the value of the difference in weight by the number of ejections and the number of ejection nozzles. That is, this discharge amount is an average value of the discharge amount in one droplet discharge head 22.

  Subsequently, the ejection amount measurement control unit 60 changes the drive voltage 73 of the drive waveform 72. Then, the discharge amount measurement control unit 60 detects the discharge amount by the same method. The discharge amount measurement control unit 60 detects the correlation between the drive voltage 73 and the discharge amount by repeatedly changing the drive voltage 73 and measuring the discharge amount.

  As a result, a graph showing the relationship between the drive voltage and the discharge amount is obtained as shown in FIG. In FIG. 7B, the horizontal axis indicates the drive voltage 73, and the right side is higher than the left side. The vertical axis indicates the discharge amount, and the upper side is larger than the lower side. The drive voltage discharge amount correlation line 74 is a correlation line indicating the relationship between the drive voltage 73 and the discharge amount. The drive voltage discharge amount correlation line 74 has a correlation in which the discharge amount increases as the drive voltage 73 increases. Since this relationship varies depending on the ejection characteristics of the droplet ejection head 22, it is preferable to measure for each droplet ejection head 22.

  In the example of the drive voltage discharge amount correlation line 74 shown in the figure, when the first drive voltage 73a is 27 volts, the discharge amount is 11 ng, and this discharge amount is defined as the first discharge amount 75a. Similarly, when the second drive voltage 73b is 26 volts, the discharge amount is 10 ng, and this discharge amount is defined as the second discharge amount 75b. The discharge amount measurement control unit 60 outputs and stores the data of the drive voltage discharge amount correlation line 74 as the drive voltage data 53 to the memory 43.

  FIGS. 7C and 7D are diagrams corresponding to the voltage-discharge position setting step of step S2. As shown in FIG. 7C, in step S <b> 2, the discharge condition setting unit 61 sets a discharge target value that is a target value of the total amount of droplets 29 discharged to the first application region 37 and the second application region 38. . The ejection target value is calculated by multiplying the areas of the first application region 37 and the second application region 38 by the thickness of the colored film 5 and dividing the result by the volume reduction rate before and after the functional liquid 26 is solidified. In the present embodiment, for example, the discharge target value in the first application region 37 is 1100 ng, and the discharge target value in the second application region 38 is 600 ng.

  Subsequently, the discharge condition setting unit 61 sets the discharge amount in each region. At this time, the discharge condition setting unit 61 sets the discharge amount so that a value obtained by multiplying the discharge amount by an integer is close to the discharge target value. More preferably, the value obtained by multiplying the discharge amount by an integer is the same as the target discharge value.

  In the first application region 37, the functional liquid 26 can be applied in an amount corresponding to the target discharge value of 1100 ng by discharging 100 times with the discharge amount being 11 ng of the first discharge amount 75 a. Since the driving voltage 73 corresponding to 11 ng of the first discharge amount 75a is 27 volts of the first driving voltage 73a, the driving voltage 73 for driving the piezoelectric element 28 in the first application region 37 is set to 27 volts of the first driving voltage 73a. To do. Similarly, in the second application region 38, the functional liquid 26 can be applied in an amount corresponding to the target discharge value of 600 ng by discharging 60 times with the discharge amount being 10 ng of the second discharge amount 75b. Since the driving voltage 73 corresponding to the second discharge amount 75b is 26 volts of the second driving voltage 73b, the driving voltage 73 for driving the piezoelectric element 28 in the second application region 38 is set to 26 volts of the second driving voltage 73b.

  That is, when the first discharge amount 75a and the second discharge amount 75b are selected, the first discharge amount 75a and the second discharge amount 75a are set such that a value obtained by multiplying the first discharge amount 75a and the second discharge amount 75b by an integer is the discharge target value. The discharge amount 75b is selected. Thereby, the total amount of droplets 29 to be ejected can be made equal to the ejection target value. When such a discharge condition cannot be found within a range in which the discharge amount can be selected, a value obtained by multiplying the first discharge amount 75a and the second discharge amount 75b by an integer is a value close to the discharge target value. It is preferable to select the first discharge amount 75a and the second discharge amount 75b.

  As shown in FIG. 7D, the ejection plan setting unit 62 sets the nozzle 24 that ejects the droplet 29 and the drive voltage 73 of the piezoelectric element 28 for each position where the droplet ejection head 22 moves. In the present embodiment, for example, the discharge plan setting unit 62 sets to discharge 100 times to the first application region 37 and 60 times to the second application region 38. Then, the position of the droplet discharge head 22 that discharges the droplet 29 and the nozzle 24 that discharges at that position are set so that the number of discharges is reached. Further, the discharge plan setting unit 62 sets the drive voltage 73 for driving the piezoelectric element 28 to 27 volts of the first drive voltage 73a in the first application region 37 and 26 volts of the second drive voltage 73b in the second application region 38. Set. Thereby, the discharge plan setting unit 62 can set the amount of the functional liquid 26 applied to the first application region 37 and the second application region 38 to the discharge target value. The discharge plan setting unit 62 stores the set position for discharging the functional liquid 26 and the data of the drive voltage 73 in the memory 43 as the discharge plan data 55.

  FIG. 8A is a diagram corresponding to the material supply process in step S3. As shown in FIG. 8A, the operator places the substrate 2 on the placement surface 11 of the stage 9 in step S3. A partition wall 4 is formed on the substrate 2 in advance. The partition 4 can be manufactured using a photolithography method. In addition, this manufacturing method is a well-known method, and description is abbreviate | omitted. Next, the droplet discharge device 6 drives the suction-type substrate chuck mechanism to fix the substrate 2 to the placement surface 11. For the sake of clarity, only one droplet discharge head 22 and nozzle 24 are shown in the figure, and the other droplet discharge head 22, nozzle 24, and head unit 18 are omitted.

  FIG. 8B is a diagram corresponding to the discharge condition setting step in step S4. As shown in FIG. 8B, in step S4, the drawing control unit 56 sets the drawing condition by dividing the scanning moving section into five sections. The first setting section 76a is a section for setting drawing conditions while the substrate 2 moves once in the Y direction. The drawing control unit 56 inputs the discharge plan data 55 from the memory 43. Then, in each section, preparation is made for outputting data of the nozzle 24 and the driving voltage 73 to be ejected corresponding to the position of the substrate 2 facing the droplet ejection head 22 to the head driving circuit 48.

  The second setting section 76 b is a section for discharging the droplets 29 to the first application region 37 of the first pattern 35. At this time, the drive voltage 73 of the piezoelectric element 28 is set to 27 volts of the first drive voltage 73a. The third setting section 76 c is a section for switching the driving voltage 73 of the piezoelectric element 28. At this time, the drive voltage 73 of the piezoelectric element 28 is switched from 27 volts of the first drive voltage 73a to 26 volts of the second drive voltage 73b. The fourth setting section 76 d is a section in which the droplets 29 are ejected to the second application region 38 of the second pattern 36. At this time, the drive voltage 73 of the piezoelectric element 28 is set to 26 volts of the second drive voltage 73b.

  The fifth setting section 76e is a section for setting drawing conditions while the substrate 2 moves once in the -Y direction. Similar to the first setting section 76 a, the drawing control unit 56 outputs to the head driving circuit 48 the data of the nozzle 24 and the driving voltage 73 that are ejected corresponding to the position of the substrate 2 facing the droplet ejection head 22 in each section. Make preparations. Further, the sub-scanning control unit 58 moves the carriage 16 to perform a line feed operation, and the main scanning control unit 57 changes the moving direction of the stage 9.

  The droplet discharge head 22 moves from the fifth setting section 76e toward the first setting section 76a. Thereafter, in the first setting section 76a, the drawing control unit 56 outputs the data of the nozzle 24 and the driving voltage 73 that are ejected corresponding to the position of the substrate 2 facing the droplet ejection head 22 in each section to the head driving circuit 48 again. Prepare to do. Further, the sub-scanning control unit 58 moves the carriage 16 to perform a line feed operation, and the main scanning control unit 57 changes the moving direction of the stage 9. As described above, discharge preparation is performed while the droplet discharge head 22 and the substrate 2 are relatively moved in one direction in the first setting section 76a and the fifth setting section 76e. Then, the discharge conditions are set so that the droplet discharge head 22 and the substrate 2 are discharged while relatively reciprocating.

  FIG. 8C to FIG. 9B are diagrams corresponding to the discharge process of step S5. As shown in FIG. 8C, in step S5, the drawing control unit 56 drives the stage 9 and the carriage 16 to move the droplet ejection head 22 to a location opposite to the location where the droplet 29 is ejected. . Then, the discharge controller 59 discharges the droplets 29 from the nozzle 24 to the first application region 37 and the second application region 38.

  As shown in FIG. 9A, in the first setting section 76a, the ejection control unit 59 outputs an instruction signal to the power supply circuit 67 so as to output the first drive voltage 73a. Then, the power supply circuit 67 switches the drive voltage 73 to 27 volts of the first drive voltage 73a and outputs it to the distribution circuit 68 of the droplet discharge head 22. In the second setting section 76b, the droplet 29 is discharged toward the first application region 37. Since the piezoelectric element 28 is driven by the first drive waveform 72a of 27 volts which is the first drive voltage 73a, the 11 ng droplet 29 having the first discharge amount 75a is discharged from the nozzle 24. Then, 1100 ng of the functional liquid 26, which is a discharge target value, is applied to the first application region 37 by performing 100 discharges.

  As shown in FIG. 9B, in the third setting section 76c, the discharge control unit 59 outputs an instruction signal to the power supply circuit 67 so as to output 26 volts of the second drive voltage 73b. Then, the power supply circuit 67 switches the drive voltage 73 to the second drive voltage 73b of 26 volts and outputs it to the distribution circuit 68 of the droplet discharge head 22. The drive voltage 73 is switched in parallel with the movement of the stage 9. Then, the drive voltage 73 is switched while the droplet discharge head 22 moves from a location facing the first pattern 35 to a location facing the second pattern 36. Thereby, in the fourth setting section 76d, the piezoelectric element 28 is driven by the second drive waveform 72b of 26 volts which is the second drive voltage 73b. As a result, a 10 ng droplet 29 having a second discharge amount 75 b is discharged from the nozzle 24. Then, 600 ng of the functional liquid 26 that is a discharge target value is applied to the second application region 38 by performing discharge 60 times.

  When the stage 9 moves and reaches a place where a line break occurs in the first setting section 76a and the fifth setting section 76e, the main scanning control unit 57 switches the moving direction of the stage 9, and the sub-scanning control unit 58 moves the carriage 16. Let Then, the main scanning control unit 57 scans and moves the stage 9.

  When the droplet discharge head 22 moves from the fourth setting section 76d to the second setting section 76b via the third setting section 76c, the discharge controller 59 outputs 27 volts of the first drive voltage 73a in the third setting section 76c. An instruction signal is output to the power supply circuit 67 so as to do so. Then, the power supply circuit 67 switches the drive voltage 73 to 27 volts of the first drive voltage 73a and outputs it to the distribution circuit 68 of the droplet discharge head 22. At this time, the driving voltage 73 is switched in parallel with the movement of the stage 9. Then, the drive voltage 73 is switched while the droplet discharge head 22 moves from a location facing the second pattern 36 to a location facing the first pattern 35. In the second setting section 76b, the droplet 29 is discharged toward the first application region 37. Since the piezoelectric element 28 is driven by the first drive waveform 72a of 27 volts which is the first drive voltage 73a, the 11 ng droplet 29 having the first discharge amount 75a is discharged from the nozzle 24. Then, 1100 ng of the functional liquid 26, which is a discharge target value, is applied to the first application region 37 by performing 100 discharges.

  The drawing process of step S11 is performed until it is confirmed that the droplets 29 have been discharged to all the locations planned in the end determination process of step S6. When the droplets 29 are ejected to all the planned locations, the process proceeds to the material removal process in step S7. In step S7, the operator releases the substrate chuck mechanism and moves the substrate 2 from the placement surface 11 to the next process.

  FIG. 9C is a diagram corresponding to the solidification step of step S8. As shown in FIG. 9C, the substrate 2 on which the functional liquid 26 is applied is placed in the drying device 79 in step S8. The drying device 79 includes a drying chamber 80. The drying chamber 80 includes a mounting table 81, and the substrate 2 is installed on the mounting table 81. The drying chamber 80 is connected to a drying gas supply unit 84 via an upper supply pipe 82 and a supply valve 83 in the drawing. Further, the drying chamber 80 is connected to an exhaust unit 87 via an exhaust pipe 85 and an exhaust valve 86 on the lower side in the drawing. Then, the dry gas 88 supplied from the dry gas supply unit 84 is supplied to the drying chamber 80 via the supply valve 83 and the supply pipe 82. Next, the dry gas 88 flows along the functional liquid 26 applied to the substrate 2. At this time, the functional liquid 26 is dried by evaporating and removing the solvent and the dispersion medium contained in the functional liquid 26 to the dry gas 88. And the colored film 5 is formed when the functional liquid 26 dries. Next, the dry gas 88 containing the solvent and the dispersion medium passes through the exhaust pipe 85 and the exhaust valve 86 and is exhausted to a processing apparatus (not shown) by the exhaust unit 87.

  In the separation step of step S9, the substrate 2 is separated. When the substrate 2 is a glass plate, the operator slides the glass cutter along the planned cutting line 39 that forms the outer shape of the color filter 1 on the substrate 2. As a result, a crack is formed in the substrate 2 along the planned cutting line 39. And the board | substrate 2 is parted by applying a stress to the board | substrate 2 so that a crack may open. The same process is performed for each color filter 1 to separate all the color filters 1. Thereby, the color filter 1 is completed. Through the above steps, the manufacturing process for manufacturing the color filter 1 by discharging the droplets 29 onto the substrate 2 is completed.

As described above, this embodiment has the following effects.
(1) According to the present embodiment, discharge conditions are prepared such that the total amount of droplets 29 discharged to the first application region 37 and the second application region 38 is equal to the discharge target value of each application region. Therefore, by using this discharge condition, it is possible to discharge the amount of droplets 29 close to the discharge target value in each application region.

  (2) According to this embodiment, the substrate 2 includes the first application region 37 and the second application region 38 having different ejection target values. Then, an ejection condition that reduces the difference between the total amount of droplets 29 to be ejected for each application region and the ejection target value is selected, and the droplets 29 are ejected using the ejection conditions. Accordingly, even when the ejection target values of the application areas are different, it is possible to apply the functional liquid 26 in an amount close to the ejection target values of the application areas.

  (3) According to this embodiment, the piezoelectric element 28 is driven by an electrical signal. Then, the driving condition of the piezoelectric element 28 is switched by switching the driving waveform 72. Switching the driving waveform 72 can be easily switched by a simple electric circuit, so that the driving conditions of the piezoelectric element 28 can be switched by a simple device.

  (4) According to the present embodiment, the ejection conditions are switched by switching the drive voltage 73 of the drive waveform 72. Since the voltage can be switched by a simple electric circuit, it can be controlled by a simple device.

  (5) According to the present embodiment, the drive voltage 73 is switched while the substrate 2 and the droplet discharge head 22 are relatively moved in the third setting section 76c. That is, the drive voltage 73 is switched while moving from the first pattern 35 to the second pattern 36. Accordingly, it is possible to eject the droplets 29 with higher productivity than when the relative movement between the substrate 2 and the droplet ejection head 22 and the switching of the drive voltage 73 are performed separately.

  (6) According to the present embodiment, the discharge condition in the first application region 37 is such that the discharge amount is 11 ng of the first discharge amount 75a and the number of discharges is 100 times. Thereby, the discharge target value is set to 1100 ng. The discharge condition for the discharge target value to be 1100 ng is possible even when the discharge amount is 10 ng of the second discharge amount 75b and the discharge number is 110 times. The number of discharges is reduced by selecting the discharge condition in which the number of discharges is 100 out of these two discharge conditions. The smaller the number of ejections, the less the number of times the piezoelectric element 28 is driven, so that the functional liquid 26 can be applied to save resources.

(Second Embodiment)
Next, an embodiment of the droplet discharge device will be described with reference to a time chart for explaining the drive waveform of the piezoelectric element of FIG. This embodiment is different from the first embodiment in that the shape of the drive waveform 72 shown in FIG. 5B is different. Note that description of the same points as in the first embodiment is omitted.

  That is, in the present embodiment, an example is shown in which the ejection conditions are switched by changing the shape of the drive waveform as shown in FIG. The horizontal axis of the figure shows the passage of time, and the time changes from left to right. The vertical axis represents voltage, and the upper side is higher than the lower side. In FIG. 10A, a first waveform 91a, a second waveform 91b, and a third waveform 91c are examples of the driving waveform 91 having different wavelengths 92. The wavelengths 92 of the first waveform 91a, the second waveform 91b, and the third waveform 91c are a first wavelength 92a, a second wavelength 92b, and a third wavelength 92c, respectively. In these three drive waveforms 91, the first wavelength 92a is the longest and the third wavelength 92c is the shortest.

  The droplet discharge head 22 of the present embodiment has a characteristic that a longer wavelength 92 has a larger discharge amount than a shorter wavelength 92. This characteristic differs depending on the structure of the droplet discharge head 22. Then, the supply voltage 71 is fixed to a predetermined voltage and the wavelength 92 is changed in the ejection characteristic measurement step of step S1. Then, the ejection amount measurement control unit 60 drives the piezoelectric element 28 with the drive waveform 91 of each wavelength 92. Thereby, a wavelength discharge amount correlation line indicating a relationship of the discharge amount with respect to the wavelength 92 can be set. This wavelength discharge amount correlation line is a line corresponding to the drive voltage discharge amount correlation line 74 in the first embodiment. Then, the first wavelength 92a of the drive waveform 91 where the discharge amount becomes the first discharge amount 75a and the second wavelength 92b of the drive waveform 91 where the discharge amount becomes the second discharge amount 75b are calculated. In the discharge process of step S5, the wavelength 92 of the drive waveform 91 is switched corresponding to the discharge amount. Thereby, the drawing control unit 56 can control the amount of the functional liquid 26 applied to the first application region 37 and the second application region 38 so as to become the discharge target value.

  In FIG. 10B, a third waveform 93a, a fourth waveform 93b, and a fifth waveform 93c show examples of drive waveforms 93 having different waveforms. The driving waveform 93 is composed of a trapezoidal positive voltage front waveform 94 and a trapezoidal negative voltage rear waveform 95 following this waveform. The front drive voltage 96 of the front waveform 94 is set to the same voltage for each drive waveform 93. On the other hand, the rear drive voltage 97 of the rear waveform 95 is set to a different voltage for each drive waveform 93. For example, the third rear drive voltage 97a in the third waveform 93a is set to a negative voltage lower than the fourth rear drive voltage 97b in the fourth waveform 93b. In the fifth waveform 93c, the rear drive voltage 97 is 0 volts, and the rear waveform 95 is not formed.

  The droplet discharge head 22 of the present embodiment has a characteristic that the lower the rear drive voltage 97 is, the higher the discharge amount is compared to the higher one. This characteristic differs depending on the structure of the droplet discharge head 22. Then, the rear drive voltage 97 is changed in the ejection characteristic measuring step in step S1. Then, the ejection amount measurement control unit 60 drives the piezoelectric element 28 with the driving waveform 93 of each rear driving voltage 97. Thereby, a voltage discharge amount correlation line showing the relationship of the discharge amount with respect to the rear drive voltage 97 can be set. This voltage discharge amount correlation line is a line corresponding to the drive voltage discharge amount correlation line 74 in the first embodiment. Then, the third rear drive voltage 97a of the drive waveform 93 in which the discharge amount is the first discharge amount 75a and the fourth rear drive voltage 97b of the drive waveform 93 in which the discharge amount is the second discharge amount 75b are calculated. In the discharge process of step S5, the rear drive voltage 97 of the drive waveform 93 is switched corresponding to the discharge amount. Thereby, the drawing control unit 56 can control the amount of the functional liquid 26 applied to the first application region 37 and the second application region 38 so as to become the discharge target value.

  In FIG. 10C, a seventh waveform 98a, an eighth waveform 98b, and a ninth waveform 98c indicate drive waveforms 98 having different waveforms. The drive voltage 99 of the drive waveform 98 is set to the same voltage for each drive waveform 98. In the drive waveform 98, the drop time 100 required for the voltage to drop in the trapezoidal waveform is set to a different time for each drive waveform 98. For example, the first fall time 100a that is the fall time 100 in the seventh waveform 98a is set to be shorter than the second fall time 100b that is the fall time 100 in the eighth waveform 98b. The second fall time 100b in the eighth waveform 98b is set to be shorter than the third fall time 100c, which is the fall time 100 in the ninth waveform 98c.

  The droplet discharge head 22 of the present embodiment has a characteristic that the discharge time is larger when the drop time 100 is shorter than when the drop time 100 is longer. This characteristic differs depending on the structure of the droplet discharge head 22. In the discharge characteristic measuring step in step S1, the fall time 100 of the drive waveform 98 is changed. Then, the discharge amount measurement control unit 60 drives the piezoelectric element 28 with the driving waveform 98 of each descent time 100. Thereby, the descent time discharge amount correlation line indicating the discharge amount with respect to the drop time 100 can be set. This fall time discharge amount correlation line is a line corresponding to the drive voltage discharge amount correlation line 74 in the first embodiment. Then, a first fall time 100a of the drive waveform 98 where the discharge amount becomes the first discharge amount 75a and a second fall time 100b of the drive waveform 98 where the discharge amount becomes the second discharge amount 75b are calculated. In the discharge process of step S5, the descent time 100 of the drive waveform 98 is switched corresponding to the discharge amount. Thereby, the drawing control unit 56 can control the amount of the functional liquid 26 applied to the first application region 37 and the second application region 38 so as to become the discharge target value.

As described above, this embodiment has the following effects.
(1) According to the present embodiment, the drive waveforms 91, 93, and 98 for driving the piezoelectric element 28 are switched in accordance with the discharge amount and discharged. At this time, the drive waveforms 91, 93, and 98 are obtained using data indicating the relationship between the conditions of the drive waveforms 91, 93, and 98 and the number of discharges when the total amount obtained by multiplying the discharge amount and the number of discharges is set to the discharge target value. The number of discharges is switched. Accordingly, the total discharge amount can be set as the discharge target value.

(Third embodiment)
Next, an embodiment of the droplet discharge apparatus will be described with reference to the drawing for explaining the discharge conditions in FIG. This embodiment is different from the first embodiment in that the discharge target value shown in FIG. 7C is not divisible by the discharge amount. Note that description of the same points as in the first embodiment is omitted.

  That is, in the present embodiment, as shown in FIG. 11, the case where the ejection target value is 1105 ng and the ejection amount of the droplet 29 ejected from the nozzle 24 is three types of 11 ng, 10 ng, and 9 ng will be described. In the voltage-discharge position setting step in step S2, the discharge condition setting unit 61 calculates the discharge amount in each region. When the discharge amount is 11 ng, 1100 ng can be discharged by setting the number of discharges to 100, and the difference from the discharge target value can be 5 ng. Further, when the number of discharges is 101, 1111 ng can be discharged, and the difference from the discharge target value is 6 ng.

  When the discharge amount is 10 ng, 1100 ng can be discharged by setting the number of discharges to 110, and the difference from the discharge target value can be 5 ng. Further, when the number of discharges is set to 111, 1110 ng can be discharged, and the difference from the discharge target value is 5 ng. When the discharge amount is 9 ng, 1098 ng can be discharged by setting the number of discharges to 122, and the difference from the discharge target value can be 7 ng. When the number of discharges is set to 123, 1107 ng can be discharged, and the difference from the discharge target value is 2 ng. The discharge condition setting unit 61 combines the discharge amount and the number of discharges as described above, and selects the condition that minimizes the difference from the discharge target value. In this embodiment, the discharge condition setting unit 61 selects a condition for discharging 123 times with a discharge amount of 9 ng. The value obtained by multiplying the discharge amount and the number of discharges at this time is 1107 ng, and the difference from the discharge target value is 2 ng. The discharge plan setting unit 62 sets the nozzle 24 that discharges the droplet 29 and the drive voltage 73 of the piezoelectric element 28 for each position where the droplet discharge head 22 moves using this discharge condition.

As described above, this embodiment has the following effects.
(1) According to the present embodiment, a plurality of ejection conditions are prepared for ejecting the droplets 29, and the ejection amount changes when the ejection conditions are changed. Then, a discharge condition with a small difference between the total amount of droplets 29 to be discharged and the discharge target value is selected, and the droplets are discharged using this discharge condition. Accordingly, it is possible to eject a quantity of liquid droplets close to the ejection target value in the application region.

In addition, this embodiment is not limited to embodiment mentioned above, A various change and improvement can also be added. A modification will be described below.
(Modification 1)
In the first embodiment, the first discharge amount 75a is 11 ng, and the second discharge amount 75b is 10 ng. The discharge amount is not limited to an integer, and may be a value including a decimal point. It may be a value that can be easily adjusted to the target discharge value. It is possible to easily set the discharge amount.

(Modification 2)
In the first embodiment, the piezoelectric element 28 is used as the pressurizing means for pressurizing the cavity 25, but other methods may be used. For example, the diaphragm 27 may be deformed and pressurized using a coil and a magnet. In addition, a heater wiring may be disposed in the cavity 25 and the heater wiring may be heated to vaporize the functional liquid 26 or expand the gas contained in the functional liquid 26 and pressurize it. In addition, the diaphragm 27 may be deformed and pressurized using electrostatic attraction and repulsion. When the discharge amount can be controlled by a driving current such as a coil or heater wiring, the driving waveform may be a current waveform. Similarly to the above-described embodiment, the discharge amount can be set to the discharge target value by switching the drive waveform for driving the pressurizing unit in accordance with the number of simultaneous discharge nozzles.

(Modification 3)
In the first embodiment, the power supply circuit 67 is installed for each droplet discharge head 22, but a different voltage may be supplied to each droplet discharge head 22 by one power supply circuit 67. Compared with the case where a plurality of power supply circuits 67 are arranged, the area occupied by the circuits can be reduced by consolidating the functions of the power supply circuit 67 into one circuit.

(Modification 4)
In the first embodiment, the example in which the color filter 1 is manufactured by applying the functional liquid 26 having a coloring function has been described. The functional liquid 26 to be applied is not limited to this. For example, the conductive function liquid 26 may be applied to form wirings and electrodes. In addition, an organic EL (electroluminescence) display device may be formed by applying a functional liquid 26 containing a material for a hole transport layer or a light emitting layer. Also in these cases, by switching the drive waveform for discharging the droplet 29, the discharge amount can be made close to the discharge target value for a plurality of patterns. And the film thickness of the film | membrane formed can be manufactured with sufficient quality.

(Modification 5)
In the first embodiment, the functional liquid 26 is ejected and applied to the substrate 2 of the color filter 1. However, the base material to be applied is not limited to the substrate 2 and has a height in the Z direction such as a rectangular parallelepiped. It can also be applied to objects with unevenness. Also in this case, the droplet 29 having the ejection target value can be ejected.

(Modification 6)
In the first embodiment, the drive waveform 72 is formed by multiplying the ejection waveform signal 69 and the supply voltage waveform 70. Then, the drive voltage 73 was changed by changing the supply voltage 71. However, the height of the ejection waveform signal 69 may be changed without changing the supply voltage 71. In this case as well, the drive voltage 73 of the drive waveform 72 can be changed similarly.

  DESCRIPTION OF SYMBOLS 1 ... Color filter, 2 ... Substrate as base material, 5 ... Colored film, 6 ... Droplet discharge apparatus, 22 ... Droplet discharge head as discharge part, 24 ... Nozzle, 28 ... Piezoelectric element as drive element, 29 ... Liquid droplets 37... First application region as a film formation region 38. Second application region as a film formation region 43. Memory as a storage unit 61 61 Ejection condition setting unit 72, 91, 93, 98 ... drive waveform, 73 ... drive voltage.

Claims (8)

A droplet discharge method for discharging a droplet a plurality of times toward a film formation region provided on a substrate,
For a discharge target value that is a target value of the total amount of the droplets discharged to the film formation region,
The droplets are ejected by selecting the ejection condition in which a value obtained by multiplying the ejection amount by an integer is close to the ejection target value from among a plurality of ejection conditions having different ejection amounts as the amount of the droplets. A droplet discharge method. The droplet discharge method according to claim 1,
The droplet discharge method, wherein the plurality of discharge conditions include the discharge condition in which a value obtained by multiplying the discharge amount by an integer is the discharge target value. The droplet discharge method according to claim 2,
The substrate includes a plurality of types of the film formation regions having different ejection target values, and the droplets are ejected under the ejection conditions selected for each type of the film formation region. Discharge method. The droplet discharge method according to claim 3,
A driving element provided for each nozzle is driven by a driving waveform which is an electric signal, and the droplet is ejected from the nozzle,
A droplet discharge method, wherein the drive waveform is switched when the discharge condition is switched. The droplet discharge method according to claim 4,
The drive element is an element that changes the discharge amount in accordance with an applied voltage, and the drive waveform is a waveform that is maintained at a predetermined drive voltage in a predetermined section, and when the discharge condition is switched, the drive waveform A droplet discharge method, wherein the drive voltage is switched. A droplet discharge method according to claim 5,
Discharging the droplets from the nozzle while relatively moving the substrate and the nozzle;
The droplet discharge method, wherein the switching of the discharge condition is performed while the base material and the nozzle are relatively moved. A method for producing a color filter having a colored film in a plurality of film forming regions partitioned on a substrate,
Set a discharge target value, which is a target value of the total amount of droplets discharged to the film formation region,
The droplets are ejected under the ejection conditions in which a value obtained by multiplying the ejection amount by an integer is close to the ejection target value among a plurality of ejection conditions having different ejection amounts as the amount of the droplets. A method for producing a color filter. A droplet discharge device that discharges droplets a plurality of times toward a film formation region provided on a substrate,
A storage unit for storing a plurality of discharge conditions with different discharge amounts;
The discharge in which a value obtained by multiplying the discharge amount by an integer from the discharge conditions is close to the discharge target value with respect to a discharge target value that is a target value of the total amount of the droplets discharged to the film formation region A discharge condition setting unit for selecting a condition;
A droplet discharge apparatus comprising: a discharge unit that discharges the droplet under the discharge condition selected by the discharge condition setting unit.

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