TWI457181B - A discharge device for a liquid material, a coating apparatus and a coating method therefor - Google Patents

Description

Discharge device for liquid material, coating device and coating method thereof

The present invention relates to an apparatus and method for accurately discharging a droplet of liquid material or dropping it by droplets, and more particularly to minimizing the re-aspiration action in a coating operation without lowering the discharge precision. Limit discharge device and method.

Conventional devices which are excellent in the accuracy of dripping or dropping liquid materials, such as those disclosed in Patent Documents 1 to 4 developed by the applicant of the present invention.

In the above-described conventional discharge device, the liquid material sucked into the metering portion is intermittently moved forward by the plunger which is disposed in a watertight and impervious manner, and the discharge mode of the liquid droplets is discharged in each forward movement.

(Patent Document 1) Japanese Patent Laid-Open Publication No. 2003-190871

(Patent Document 2) Japanese Patent Laid-Open Publication No. 2004-160314

(Patent Document 3) Japanese Patent Laid-Open Publication No. 2004-160276

(Patent Document 4) Japanese Patent Laid-Open Publication No. 2005-40770

The discharge mode of the conventional device is limited in the amount of suction to the measuring tube, and there is a case where the liquid material required for the entire workpiece cannot be sucked. In this case, it is necessary to perform the re-suction operation in the middle of the coating operation, and there is a problem that the productivity is lowered.

Here, when the size of the measuring tube is increased, there are the following problems:

That is, when the diameter of the measuring tube is increased to increase the suction amount of the liquid material, the diameter of the plunger is also inevitably enlarged, so that a large amount of liquid material is dripped with a slight movement of the plunger, and as a result, it is difficult to perform minute discharge. The problem.

On the other hand, when the length of the measuring tube is increased, in addition to the increase in size of the device, there is also a problem that it is difficult to improve the discharge accuracy.

It is an object of the present invention to provide a discharge apparatus and method that minimizes the re-suction operation during a coating operation without reducing the discharge accuracy.

The apparatus of the present invention is constructed as follows. that is:

The liquid material discharge device according to the first aspect of the present invention includes a storage portion having a liquid material, a plurality of metering portions through which the plunger is inserted, a plunger driving device, and a plurality of nozzles corresponding to the respective metering portions in one-to-one correspondence; A liquid material discharge device that discharges the liquid material to the metering portion in plural times; wherein the plunger driving device is a plunger driving device that moves all the plungers forward and backward simultaneously.

According to a second aspect of the invention, in the first aspect of the invention, the measuring unit is configured to have the same capacity.

According to a third aspect of the invention, in the first or second aspect of the invention, the metering unit is provided with a switching valve having a first position that allows the metering unit to communicate with the nozzle and a second position that connects the metering unit and the storage unit, and is provided There is a valve drive device that can switch the positions of the respective switching valves at the same time.

According to a third aspect of the invention, the plunger driving device and the valve driving device are disposed in a vertical direction with respect to the plurality of measuring units.

According to a fifth aspect of the present invention, in the third or fourth aspect of the present invention, a block body in which the switching valve is disposed is provided, and a flow path in which a liquid material flows from the storage container toward each switching valve branch is provided in the block body.

According to a sixth aspect of the invention, the measuring unit is configured by a measuring tube attachable to the block, and is disposed adjacent to each other.

According to a seventh aspect of the invention, in the fifth aspect, the measuring unit is formed in the block.

According to a seventh aspect of the invention, in the seventh aspect of the invention, the storage unit is formed in the block.

The coating device according to a ninth aspect of the invention includes a gantry having a platform, and a frame extending over the gantry and movable in one direction, and the casing is provided with the discharge device according to any one of the first to eighth aspects.

The method of the present invention is constructed as follows. that is:

According to a tenth aspect of the present invention, in the method of discharging a liquid material, the liquid material is filled in the measuring portion of the insertion plunger from the storage portion, and the liquid material in the measuring portion is repeatedly used by repeatedly moving in and out of the plunger and stopping the inflow and out. a method for discharging a discharged liquid material; wherein a plurality of measuring portions and a plurality of nozzles corresponding to each of the measuring portions are provided, and a plurality of plungers are simultaneously moved by a plunger driving device, thereby simultaneously discharging Liquid material in all metering sections.

According to a tenth aspect of the invention, the metering unit is provided with a switching valve having a first position that allows the measuring unit to communicate with the nozzle and a second position that allows the measuring unit to communicate with the storage unit, and transmits the driving The device simultaneously switches the switching valves to discharge the liquid material.

According to the present invention, a small amount of liquid material can be dripped from a plurality of nozzles with high precision.

Furthermore, the device can be constructed by two driving sources, and the device can be formed elongated by longitudinally arranging them.

Further, since the supplied liquid material can be branched into the apparatus and introduced into the plurality of measuring portions, the amount of the liquid material remaining in the storage portion can be reduced, and the liquid material can be used without waste.

A preferred embodiment of the present invention is, for example, a liquid material discharge device including a plurality of metering portions arranged adjacent to each other, wherein the metering portion includes a plunger and a nozzle, and is provided with a plurality of plungers moving forward and backward simultaneously Drive unit.

The measuring unit temporarily stores a space for discharging the liquid material from the nozzle through the movement of the plunger, and the volume is configured to be suitable for discharging a small amount of liquid material with high precision. The reason why the measuring unit is provided in plural is that the volume of the entire measuring unit is not increased, but the volume of the entire measuring unit is increased. For example, the configuration of the measuring unit may be such that the plurality of measuring units are a plurality of measuring tubes attached to the valve body, and the valve body includes a flow path for branching the liquid material into the respective measuring tubes from the storage container. As another configuration of the measuring unit, it is possible to disclose a configuration in which a plurality of metering holes are provided in the metering block and a flow path in which the liquid material branches into the metering holes from the storage container. Regardless of the aspect, the horizontal position of the front end of the nozzle is aligned.

The reason why the metering portion and the nozzle are configured in one-to-one correspondence is that in the case where two nozzles are dropped from one metering portion, the delicate fluid of the liquid material pressurized by the plunger in the metering portion is equalized, and liquid may not be present. The case where the nozzles flow equally on both nozzles. In this regard, when each of the measuring portions has a nozzle, the flow path from each of the measuring portions to the nozzle discharge port can be made to have the same closed shape (although a switching valve can be disposed), so that the accuracy can be accurately performed. Execution.

Further, when the capacity between the plunger tip end and the switching valve is made equal when the liquid material is filled, the plunger sliding in the metering portion is simultaneously introduced and discharged, and the flow path can be generated as the plunger enters and exits. The volume reduction is up to the same ratio. It is also possible to set all the measuring sections to the same capacity and simultaneously discharge the same amount of liquid material from all the nozzles.

Further, if a seal portion (large diameter projection portion) wider than the rod is provided at the end portion of the plunger, the sliding area is reduced, and the plunger can be moved at a high speed. At this time, it is preferable that the flow path that connects the metering portion and the nozzle is formed as a substantially straight line.

Further, it is preferable that each of the measuring units includes a switching valve and a driving device that simultaneously switches the switching valves. The switching valve may be of a sliding type, a one-way rotating type, or a reciprocating rotating type.

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited by the examples.

[Example 1] "Overall composition"

The apparatus of this embodiment will be described with reference to Figs. Further, in Fig. 4, a plunger A30 is provided on the back surface of the plunger B31, a nozzle A55 is provided on the back surface of the nozzle B56, a valve A57 is provided on the back surface of the valve B58, and a valve plug is provided on the back surface of the valve insertion hole B62. Set hole A61.

In the discharge device of the present embodiment, a plate A11, a plate B12, and a plate C13 are attached to the base 10 to form a frame, and the frame is provided with a [1] plunger driving portion, [2] a plunger portion, and [ 3] Liquid delivery section and [4] valve section.

[1] The plunger drive unit is composed of a motor A20, a carriage 21, and a slider 22.

The plunger driving portion is configured to be rotationally driven by the motor A20 fixed to the plate B12, so that the slider 22 can be moved in the extending direction of the slider 21 on the slider 21 fixed to the base 10. The components of the plunger drive portion are arranged in line symmetry with respect to the central axis of the base 10.

[2] A part of the plunger is composed of a plunger A30, a plunger B31, a measuring tube A32, and a measuring tube B33.

In the plunger portion, the plunger A30 and the plunger B31 are respectively fixed to the slider 22 of the plunger driving portion via the screw A34 and the screw B35. The plunger A30 is slidably inserted into the inner wall surface of the measuring tube A32, and the plunger B31 is slidably inserted into the inner wall surface of the measuring tube B33.

The measuring tube A32 and the measuring tube B33 are attached and fixed to the holes formed in the valve body 50, and the plunger A30 and the plunger B31 are respectively tightly connected to the measuring tube A32 and the measuring tube B33 by the driving of the motor A20. Sliding on the wall.

Here, the tip end of each of the plunger A30 and the plunger B31 on the side of the measuring tube can be formed to have a larger diameter (that is, a sealing portion) than the diameter of the main body of the plunger shaft in order to be surely adhered to the inside of the measuring tube.

The metering tube A32 and the metering tube B33 are line-symmetrical with respect to the central axis of the base 10 and are disposed close to each other. Thus, in the present embodiment, one metering tube is not increased or widened, and the discharge amount is increased by providing a plurality of numbers to prevent an increase in size of the discharge device.

The apparatus of the present embodiment is configured such that the plunger A30 and the plunger B31 are simultaneously moved forward or backward in the measuring tube by the rotation of the motor A20. That is, when the plunger A30 moves forward in the measuring tube A32, the plunger B31 also moves forward in the measuring tube B33, and when the plunger A30 moves backward in the measuring tube A32, the plunger B31 At the same time, the retreating movement is performed in the measuring tube B33 at the same time.

[3] The liquid delivery unit is composed of a storage container 40 and a liquid delivery tube 41.

More specifically, the liquid delivery unit is composed of a storage container 40 that stores a liquid material, and a liquid delivery tube 41 that communicates the storage container 40 with the valve body 50.

The liquid delivery tube 41 is in communication with the liquid delivery tube 43 extending toward the bottom of the storage container 40, and the liquid material stored in the storage container 40 is stored by the air pressure supplied from the pressure supply tube 42 reaching the upper end of the storage container 40. The pressure is sent to the valve body 50.

The storage container 40 is placed on the plate B12 so as to be inclined, and the plate A11 is detachably held and fixed by being supported by the main body portion.

[4] The valve portion is composed of a valve body 50, a motor B51, a gear train 52, a shaft A53, a shaft B54, a nozzle A55, a nozzle B56, and a rotation detecting mechanism 70.

The valve portion is configured to be rotated by the motor B51 supported by the susceptor 10, and the two shafts arranged in parallel (ie, the shaft A53 and the shaft B54) are rotated via the gear train 52, and the valve fixed to the plate C13 is fixed. The two valves (i.e., valve A57 and valve B58) disposed in the valve insertion hole A61 and the valve insertion hole B62 of the body 50 are rotatable. Each of the valves includes a through hole that allows each of the measuring tubes to communicate with each of the nozzles, and a groove that extends in a longitudinal direction (horizontal direction) of the valve on a circumferential surface orthogonal to the through hole, the grooves and valves The inner wall surfaces of the insertion holes interact to form a flow path for connecting the respective measuring tubes to the storage container 40.

The rotation detecting mechanism 70 is composed of a sensor 71 and a detecting plate 72. The detecting plate 72 is a disk having a notch and is rotated in accordance with the rotation of the motor B51. The detection plate 72 is located in the formation The shape of the sensor 71 is a recess of the sensor 71. In the sensor 71, the upper end of the concave portion is a light-emitting portion, and the lower end of the concave portion serves as a light-receiving portion. By detecting the notch of the plate 72, the light emitted by the light-emitting portion can be lighted or blocked by the light-receiving portion. Thereby, the rotational position of the valve B58 is controlled based on the light from the light-emitting portion to the position at which the light-receiving portion of the sensor 71 starts to be shielded or the position at which the light-emitting is started.

A nozzle A55 and a nozzle B56 are detachably disposed at the bottom of the valve body 50.

In the holes penetrating the valve body 50, the metering tubes A and B are attached and fixed. Further, of course, the hole body portion that is bored on the valve body 50 may be configured as a metering tube.

The valve body 50 is provided with a flow path having a branch path for conveying the liquid material supplied through the liquid material supply port 59 communicating with the liquid delivery pipe 41 to the valve A57 and the valve B58, respectively. Thus, since it is configured to flow into the measuring tubes A and B via the branch of the supplied valve body 50, it is not necessary to provide a plurality of storage containers.

The shaft A53 is configured to be detachably coupled to the valve A57 (in addition, in FIGS. 2 and 4, the shaft A53 is located on the back surface of the shaft B54). The valve A57 is rotated by the shaft A53 to obtain a first position in which the measuring tube A32 communicates with the liquid delivery tube 41 and a second position in which the measuring tube A32 communicates with the nozzle A55.

The shaft B54 is configured to be detachably coupled to the valve B58. The valve B58 is rotated by the shaft B54 to obtain a first position that allows the metering tube B33 to communicate with the liquid delivery tube 41, and a second position that allows the metering tube B33 to communicate with the nozzle B56.

The valve A57 and the valve B58 are configured to be simultaneously switched between the respective first and second positions by the rotation of the motor B51.

In other words, the motor A20 and the motor B51 are connected to the control device 60, and operate according to the command of the control device 60.

Thus, the apparatus of this embodiment is provided with two motors. Moreover, the plurality of plungers are simultaneously moved by one of the motors, and the plurality of valves simultaneously act by the other motor. In such a configuration, the motor A20 and the motor B51 are vertically arranged via the slider. With this configuration, the device can be formed elongated. Further, the motor A20 and the motor B51 are preferably disposed coaxially on the center or near the center of the base 10.

When a plurality of drip devices are mounted on a mobile robot moving in the XY direction, such a slim configuration can increase the number of dripping devices, which is preferable.

Furthermore, since all the plungers and all the valves can be operated by the two motors, the device can be configured lightly, and in the coating device equipped with the dropping device, the dropping device is oriented in the X direction or the Y direction. It is convenient when moving.

"Liquid discharge operation"

The motor B51 is rotated, the valve A57 and the valve B58 are placed at the first position, and the measuring tube A32 and the measuring tube B33 are respectively connected to the liquid delivery tube 41.

Next, the motor A20 is rotated, the plunger A30 and the plunger B31 are moved backward, and a necessary amount of liquid material is sucked into the measuring tube A32 and the measuring tube B33.

Next, the motor B51 is operated to bring the valve A57 and the valve B58 to the second position, and the measuring tube is connected to the nozzle. That is, the metering tube A32 is communicated with the nozzle A55, and the metering tube B33 is communicated with the nozzle B56.

In order to discharge a desired amount of the liquid material, the motor A20 is rotated, and the plunger A30 and the plunger B31 are moved forward by a predetermined amount, and the liquid material is discharged from the nozzle A55 and the nozzle B56.

At this time, the plunger A30 and the plunger B31 are quickly stopped by the rapid advancement, and a small amount of the liquid material can be dripped from the nozzle with high precision. The liquid material can be continuously dropped by the rapid advancement and subsequent rapid stop action.

In order to allow the liquid material to continuously drip, it is of course necessary to pump the necessary amount in advance.

Here, by the rapid continuation of the rapid advancement of the plunger, a small amount of liquid material is dripped from the nozzle with high precision. For example, by moving the plunger in and out of the inner wall surface of the measuring tube to move in and out, the discharge amount of the liquid droplet discharged from the discharge port communicating with the measuring tube is adjusted, and thus the amount of liquid droplets is adjusted. The adjustment method is a method of adjusting the movement speed from the start of the deceleration to the stop of the plunger moving in and out, so that the droplet discharged from the discharge port maintains a certain amount of droplets per discharge. Removing the plunger to move the liquid material into the measuring tube from the storage container, and repeating the movement of the plunger in and out and stopping the inflow and out, thereby separating the liquid material in the measuring tube several times. discharge. Further, regarding the discharge method, the applicant of the present application has disclosed it in Patent Document 4.

After the drip operation of the desired number of times is performed, the motor B51 is again rotated, the valve A57 and the valve B58 are set to the first position, and the discharge operation can be continuously performed by repeating the above-described operation.

The coating device 5 equipped with a plurality of the dropping device 1 of the present embodiment is shown in Fig. 5 .

The coating device 5 includes a gantry 7, a movable frame A81, and a movable frame B82. The gantry 7 has a platform 6 on which a workpiece is placed, and the movable frame A81 is supported by a pair of supports fixed on the gantry 1. The body is supported and spans the short side direction (X direction) of the gantry 1, and the movable frame B82 similarly straddles the X direction of the gantry 1. On the side faces of the movable frame body A81 and the movable frame body B82, a plurality of dropping devices 1 are movably attached via the movable member in the X direction. The drip device 1 is composed of a discharge device and a Z-direction drive device that can move the discharge device in the vertical direction (Z direction). The platform 6 is configured to be movable in the X direction by the X rail, and is configured to be movable in the Y direction by the Y slider and the Y rail provided with the X rail. Further, the platform 6 may be provided with a θ rotation means for moving the workpiece in the θ-axis direction and positioning at a predetermined angle. The rails in the X direction and the Y direction may be configured to include a linear motor magnet and a linear slide. However, the present invention is not limited thereto. For example, the slide may be provided with a motor and interlocked with the motor. The rotating ball screw has a nut that is linearly moved in conjunction with the rotation of the ball screw.

This embodiment is important in that it is not a drop from a metering tube branch to the two nozzles. That is, the nozzle, the measuring tube, and the plunger are configured in a single combination, and the discharge device is provided with a plurality of such combinations.

In the case where the branch is dropped from the measuring tube to the two nozzles, the delicate fluid of the liquid material pressurized by the plunger in the measuring tube is equalized, and the fluid cannot flow uniformly to both nozzles, but by the embodiment The composition can reliably drop the liquid material.

In the present embodiment, a discharge device configured with two nozzles is exemplified, but the technical idea of the present embodiment naturally also covers a discharge device configuration in which two or more nozzles are disposed.

Furthermore, since the nozzle, the metering tube and the plunger are a combination, it is of course also necessary to have the same number of metering tubes and plungers as the number of nozzles.

[Embodiment 2] "Overall composition"

The apparatus of the second embodiment will be described with reference to Figs. 6 to 8 . Further, in Fig. 8, a plunger A30 is provided on the back surface of the plunger B31, a nozzle A55 is provided on the back surface of the nozzle B56, a valve A57 is provided on the back surface of the valve B58, and a valve insertion hole A61 is provided on the back surface of the valve insertion hole B62. A metering hole A64 is provided on the back side of the metering hole B65.

The discharge device of the present embodiment is different from the discharge device of the first embodiment in that the valve insertion holes A61 and B62, the storage portion 63, and the metering block 36 in which the metering holes A64 and B65 are formed are provided.

The metering block 36 is fixed to the plate C13, and is provided with a hole through which the plungers A31 and B31 are inserted, and a side surface provided with a liquid material supply port 59 communicating with the liquid delivery pipe 41. The liquid material supplied from the liquid material supply port 59 is temporarily stored in the storage portion 63 formed inside the metering block 36. The liquid material stored in the storage portion 63 is sent to the metering hole A64 and the metering hole B65 via the grooves formed on the respective circumferential surfaces of the valve A57 and the valve B58. The liquid suction step of the discharge device is the same as that of the first embodiment, and the storage portion 63 is kept in communication with the metering hole A64 and the metering hole B65, and the plunger A30 and the plunger B31 are simultaneously retracted and moved by the motor A20.

The liquid discharge step of the discharge device is also the same as in the first embodiment. First, by rotating the motor B51 supported by the susceptor 10, the two shafts arranged in parallel (ie, the shaft A53 and the shaft B54) are rotated via the gear train 52, whereby the metering holes and the nozzles are respectively provided. The through holes of the valve are in communication. Then, the plunger A30 and the plunger B31 are simultaneously advanced by the motor A20, and then stopped abruptly, whereby a small amount of liquid material is dripped from the nozzle with high precision. This action is repeated several times to perform the discharge operation until the liquid material sucked into the metering holes A64 and B65 is exhausted.

In the discharge device of this embodiment, two or more metering holes, plungers, and nozzles may be disposed. Further, the discharge device of the present embodiment can of course be mounted on the coating device 5 of the first embodiment.

(industrial availability)

The present invention is applicable to a flat panel display manufacturing step, such as a liquid crystal dropping step in a liquid crystal panel manufacturing step.

1. . . Drip device

5. . . Coating device

6. . . platform

7. . . shelf

10. . . Pedestal

11. . . Board A

12. . . Board B

13. . . Board C

20. . . Motor A

twenty one. . . Slide

twenty two. . . Slider

30. . . Plunger A

31. . . Plunger B

32. . . Measuring tube A

33. . . Metering tube B

34. . . Screw A

35. . . Screw B

36. . . Metering block

40. . . Storage container

41. . . Liquid delivery tube

42. . . Pressure supply pipe

43. . . Liquid delivery tube

44. . . Liquid material

50. . . Valve body

51. . . Motor B

52. . . Gear set

53. . . Axis A

54. . . Axis B

55. . . Nozzle A

56. . . Nozzle B

57. . . Valve A

58. . . Valve B

59. . . Liquid material supply port

60. . . Control device

61. . . Valve insertion hole A

62. . . Valve insertion hole B

63. . . Storage department

64. . . Metering hole A

65. . . Metering hole B

70. . . Rotating detection mechanism

71. . . Sensor

72‧‧‧Test board

81‧‧‧ movable frame A

82‧‧‧ movable frame B

Fig. 1 is a front elevational view showing the dripping device of the first embodiment.

Figure 2 is a side elevational view of the apparatus of Figure 1.

Figure 3 is a front cross-sectional view of the position of the broken line in Figure 2.

Figure 4 is a side cross-sectional view of the position of the broken line in Figure 1.

Fig. 5 is a perspective view of a coating device on which the dropping device shown in Fig. 1 is mounted.

Fig. 6 is a front elevational view showing the dripping device of the second embodiment.

Figure 7 is a side elevational view of the apparatus of Figure 6.

Figure 8 is a front cross-sectional view of the position of the broken line of Figure 7.

10‧‧‧ Pedestal

11‧‧‧ Board A

12‧‧‧ Board B

13‧‧‧ Board C

20‧‧‧Motor A

21‧‧‧Slide

22‧‧‧Sliding parts

30‧‧‧Plunger A

31‧‧‧Plunger B

32‧‧‧Measuring tube A

33‧‧‧Measuring tube B

34‧‧‧ Screw A

35‧‧‧ Screw B

50‧‧‧ valve body

51‧‧‧Motor B

55‧‧‧Nozzle A

56‧‧‧Nozzle B

57‧‧‧Valve A

58‧‧‧Valve B

Claims (13)

A liquid material discharge device comprising: a storage portion for liquid material; a plurality of metering portions through which a plunger is inserted; a plunger driving device; a plurality of nozzles corresponding to each metering portion in one-to-one correspondence; and a connecting metering portion a first position of the nozzle and a second position connecting the metering portion and the storage portion, respectively, a switching valve provided to each metering portion; and a valve driving device capable of simultaneously switching the positions of the switching valves; the discharging device is disposed in the coating a frame extending on the platform of the cloth device; wherein the plunger driving device is a plunger driving device that can move all the plungers forward and backward simultaneously, and the plunger driving device and the valve driving device are The plurality of measuring units are disposed in the vertical direction with respect to the plurality of measuring units, and the discharge device is configured to have a small width. The apparatus for discharging a liquid material according to the first aspect of the invention, wherein the measuring unit is configured to have the same capacity. A liquid material discharge device according to claim 1 or 2, wherein a block body in which the switching valve is disposed is provided, and a flow in which the liquid material flows from the storage portion to the switching valve branches is provided in the block body. road. The liquid material discharge device according to claim 3, wherein the measuring unit is configured by a measuring tube attachable to the block, and disposed adjacent to each other. A liquid material discharge device according to claim 3, wherein the meter body is formed in the block body. A liquid material discharge device according to claim 5, wherein the block is formed with a second storage portion for temporarily storing the liquid material from the storage portion. The liquid material discharge device according to claim 3, wherein the storage portion of the liquid material is disposed in a vertical direction with respect to the plurality of metering portions, and the storage portion of the liquid material and the block are connected by a liquid transfer tube. body. A coating apparatus comprising a platform and a frame extending on the platform, wherein the casing is provided with a discharge device according to claim 1 or 2. The coating device of claim 8, wherein the coating device is provided with a plurality of the above-described discharge devices. A method of coating a liquid material, which comprises coating a workpiece placed on a platform using a coating device as described in claim 8 of the patent application. A method of coating a liquid material, which comprises coating a workpiece placed on a platform using a coating device as described in claim 9 of the patent application. The method of coating a liquid material according to claim 10, wherein the liquid material is a liquid crystal. The method of coating a liquid material according to claim 11, wherein the liquid material is a liquid crystal.