JP2006126790A - Liquid crystal application device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet type liquid crystal application device with which application is uniformly and accurately controlled over an entire substrate while the liquid crystal is quickly applied. <P>SOLUTION: In relation to the device to apply the liquid crystal to the substrate in the LCD manufacturing process, the device has a stage 110 to support the substrate, a head portion 130 to apply the liquid crystal to the substrate on the stage while moving relative to the stage, and a driving portion 140 to make the stage and the head portion move relative to each other. The liquid crystal application device is characterized by including an image pickup unit 133 to pick up an image of the state of the liquid crystal applied with the head portion, and a control portion 150 to judge suitability of the liquid crystal application based on the image picked up with the image pickup unit and to control the driving portion so as to adjust the speed of the relative motion based on the judgement of the suitability. Thereby, the transfer speed of the liquid crystal on the liquid crystal application is adjusted, based on the judgement of the suitability of the liquid crystal application. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for applying a liquid crystal on a substrate in an LCD manufacturing process, and more particularly to a liquid crystal application apparatus that can determine the suitability of liquid crystal to be applied and adjust the transfer speed of the liquid crystal application.

  In general, as shown in FIG. 1, an LCD (Liquid Crystal Display) is assembled by a lower substrate 10 on which a drive circuit such as a TFT (Thin Film Transistor) is formed and an upper substrate 20 on which a color filter is formed. Join and complete. In this process, the liquid crystal 11 is dropped on the lower substrate 10, and a sealing material 21 is applied to the frame portion of the upper substrate 20, and is fixed when the substrates 10 and 20 are joined to prevent liquid crystal leakage.

  Here, the dropping of the liquid crystal has been performed by a liquid crystal dropping device. That is, as shown in FIG. 2, the liquid crystal 11 is dropped in a drop shape from the liquid crystal dropping device 30 installed on the lower substrate 10 at a constant interval. Usually, the liquid crystal dropping device 30 is fixed and drops the liquid crystal 11 at a constant time interval, and the liquid crystal 11 is arranged at a constant interval while the lower substrate 10 is moved below the liquid crystal dropping device 30 in the X and Y directions. It is dripped. In this case, the adjustment of the thickness of the liquid crystal layer between the LCD substrates is achieved by adjusting the distance between the liquid crystals 11 or adjusting the amount of liquid crystal dropped once.

  However, according to such a liquid crystal dropping method, it is difficult to form a liquid crystal layer having a desired thickness because the liquid crystal 11 cannot be dropped from the liquid crystal dropping device 30 in a uniform amount every time. In some cases, the amount of dripping of the liquid crystal is excessive and insufficient, resulting in a luminance problem in the bonded LCD. In addition, there is a problem that the peripheral edge of the liquid crystal evaporates during the time until the liquid crystal is dropped after the liquid crystal is dropped and the substrate is stained, thereby increasing the defect occurrence rate of the bonded product.

In order to solve such a problem, Patent Document 1 discloses an ink jet type liquid crystal coating method. According to this method, as shown in FIG. 3, the liquid crystal is discharged through the plurality of nozzles provided in the ink jet apparatus 40. In other words, if an oscillator (Resonator) 41 of the ink jet apparatus 40 generates a vibration having a constant frequency, a certain amount of liquid crystal 44 is discharged from the discharge portion 43 onto the substrate 10 by the vibration of the oscillation plate 42 connected to the oscillator. Discharged. Accordingly, there is an advantage that the liquid crystal is applied quickly and the liquid crystal can be evenly distributed on the substrate.
US Patent Application Publication No. 2002/167638

  However, even when using such an ink jet method, the amount of liquid crystal applied to the substrate is not accurately controlled as in the case of the liquid crystal dropping method, and the liquid crystal application amount is excessive or insufficient. There was a problem.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet type liquid crystal coating apparatus capable of controlling liquid crystal coating in a uniform and accurate amount over the entire substrate while being rapidly applied.

  In order to achieve the above object, the present invention provides a stage for supporting a substrate, a head part for applying liquid crystal to the substrate on the stage while moving relative to the stage, and a relative movement between the stage and the head part. In the liquid crystal coating apparatus including the driving unit, the imaging device that captures the state of the liquid crystal applied by the head unit, and whether or not the applied liquid crystal is appropriate based on the image captured by the imaging device And a control unit that controls the driving unit to adjust the speed of the relative motion based on the determination of suitability.

  Here, the imaging device may include a first camera attached to the head unit.

  The imaging device may include a second camera that is arranged in parallel with the substrate and supported by the stage, and that images the state of the liquid crystal applied on the purge plate on which the test liquid crystal application is performed. . At this time, the stage includes a transfer guide that is coupled to the second camera so that the second camera can reciprocate along the purge plate, and a drive unit that drives reciprocating transfer of the second camera. It can also be included.

  As described above, according to the liquid crystal coating apparatus according to the present invention, liquid crystal can be applied not only quickly but also in a uniform and accurate amount over the entire substrate.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 4, one embodiment of the liquid crystal coating apparatus according to the present invention is coupled to a stage 110 that supports the substrate 1 and each component, a guide unit 120 that slides on the stage 110, and a guide unit 120. A head unit 130 that applies liquid crystal to the substrate 1 while being transferred, a drive unit 140 (see FIG. 6) that drives the guide unit 120, and a control unit 150 (see FIG. 6) that controls the operation of each unit. The

  The guide unit 120 includes a beam-shaped Y-axis guide 121 and two X-axis guides 122 fixedly coupled to lower portions of both ends of the Y-axis guide 121. The X-axis guide 122 slides on the transfer rail 111 formed in the X direction at both ends of the stage 110. The head plate 131 of the head unit 130 is slidably coupled to the Y-axis guide 121 and transferred in the Y direction on the Y-axis guide 121.

  The head unit 130 includes a head plate 131 slidably coupled to the Y-axis guide 121, a plurality of inkjet jet heads 132 fixedly arranged in a row at the lower end of the head plate 131, and an upper portion of each jet head 132. The first camera 133 is provided.

  As shown in FIG. 5, the jet head 132 is filled from the liquid crystal storage tank 134 through the pump 135 and the supply line 136. Each jet head 132 has 256 nozzles (not shown) arranged in a row, and each nozzle of the jet head 132 is individually controlled by the control unit 150 to operate.

  A plurality of first cameras 133 for measuring the liquid crystal application state of the jet head 132 in real time are attached to the head unit 130. The first camera 133 images the liquid crystal discharged from the nozzle of the jet head 132 to be imaged onto the substrate 1. The liquid crystal image captured by the first camera 133 is transmitted to the control unit 150 (see FIG. 6), and the control unit 150 transmits the liquid crystal through each nozzle of the jet head 132 based on the image received from the first camera 133. Whether or not to discharge is determined. Detection of nozzles that do not actually discharge liquid crystal is observed on the substrate 1 in line form.

  The controller 150 determines the number of lines on which the liquid crystal is not ejected, and after the application is completed, the controller 150 reapplies the non-applied line portion. That is, the head unit 130 is rotated by operating other nozzles adjacent to the nozzles from which the liquid crystal was not discharged. If all the nozzles provided in one jet head 132 do not operate, a belt-like shape is observed on the substrate 1. In this case, the Y-axis guide 121 is driven to move the adjacent jet head 132 in the Y direction. After a predetermined amount of movement, liquid crystal is jetted onto the band portion.

  A plurality of the first cameras 133 can be installed in the same number as the number of jet heads 121 installed, but can be used by installing only one of the jet heads 121. In order to secure a viewing angle, the image can be transferred in the horizontal direction (Y direction) and the vertical direction (Z direction).

  On the other hand, a purge plate 112 is positioned on one side of the substrate 1 on the stage 110. The purge plate 112 is for test discharge of liquid crystal, and enables the discharge amount to be tested before or after applying the liquid crystal to the substrate 1 when the substrate is changed.

  The stage 110 further includes a second camera 113 so that the purge plate 112 can be imaged. The second camera 113 can image while moving along the purge plate 112. A transfer guide 114 and drive means (not shown) are provided. Here, the second camera 113 is used to calculate the nozzle ejection amount and the transfer speed of the head unit 130 by measuring the excess and deficiency of the liquid crystal applied to the purge plate 112 and the presence or absence of ejection. That is, if the image of the liquid crystal test-applied on the purge plate 112 is transmitted to the control unit 150 through the second camera 113 (see FIG. 6), the control unit 150 calculates the amount of liquid crystal through the transmitted image. The controller 150 is provided with a liquid crystal amount corresponding to various liquid crystal ejection modes as a database, and the liquid crystal amount is measured by a method of matching the transmitted image with the database.

  The controller 150 compares the measured amount of liquid crystal with the total amount of liquid crystal applied on the substrate 1 to calculate the total number of liquid crystal discharged. Then, the total number of liquid crystal discharged is divided by the total number of nozzles to calculate the number of liquid crystal discharged per unit nozzle. On the other hand, since the number of liquid crystal discharged per unit time of the nozzle is fixed, the liquid crystal discharge time of the nozzle is calculated based on the number of liquid crystal discharged, and as a result, the transfer speed of the head unit 130 is calculated.

  The stage unit 110 further includes a cleaning container 115 and a wiper 116 for cleaning the jet head 132. The cleaning container 115 is filled with a solvent, and when the nozzle of the jet head 132 is clogged or foreign matter is attached to the jet head 132, it plays a role of cleaning and removing this, and the wiper 116 is cleaned. Play a role. Wiping by the wiper 116 is performed while the head unit 130 moves back and forth on the wiper.

  An example of the operation process of the liquid crystal coating apparatus having the above configuration is as follows.

  First, as a preparation stage, the liquid crystal is test-coated with the head unit 130 positioned on the purge plate 112, and the liquid crystal image is captured while the second camera 113 is transported along the transport guide 114. The control unit 150 measures the amount of liquid crystal ejected based on the liquid crystal image received from the second camera 113 and then calculates the transfer speed of the total liquid crystal application amount comparison head unit 130 applied to the target substrate 1. Then, a control signal for the driving unit 140 is generated.

  When the target substrate 1 is loaded on the stage 110, the driving unit 140 applies liquid crystal while moving the head unit 130 at a constant speed according to a control signal from the control unit 150. During the application process of the liquid crystal, the first camera 133 images the application state in real time, transmits this to the control unit 150 to measure the unapplied part, and the liquid crystal application is again applied to the unapplied part when the head unit 130 is forwarded. Applied.

  On the other hand, the head unit 130 can operate some or all of the plurality of jet heads 121 depending on the size of the substrate 1 to be loaded. The jet head 121 can be operated part by part.

  In the disclosed embodiment of the present invention, the stage 110 is fixed and the head unit 130 is reciprocally transferred at the top of the stage 110. However, the head unit 130 is fixed and the stage 110 is the head unit. It can also be set as the structure transferred below 130, and such embodiment is also contained in the indication range of the present invention.

  Further, the liquid crystal coating apparatus disclosed above is provided with a plurality of jet heads 132 and first cameras 133, but the case where one each is provided is also included in the disclosure scope of the present invention. In this case, the liquid crystal application by the head unit 130 is performed such that the front and rear transfer (X direction) and the left and right transfer (Y direction) are performed in parallel as in the printing method of the ink jet printer.

It is a conceptual diagram for demonstrating the conventional board | substrate joining process. It is a conceptual diagram for demonstrating the conventional liquid crystal dropping apparatus. It is a conceptual diagram for demonstrating the conventional liquid crystal coating device of the inkjet system. It is a perspective view which shows one Example of this invention. It is the schematic for demonstrating the liquid-crystal supply line of FIG. It is a block diagram which shows the control relationship of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 10 Lower substrate 11 Liquid crystal 20 Upper substrate 21 Sealing material 30 Liquid crystal dropping device 40 Inkjet device 42 Oscillating plate 43 Discharge unit 110 Stage 111 Transfer rail 112 Purge plate 113 Second camera 114 Transfer guide 115 Cleaning tank 116 Wiper 120 Guide unit 121 Y-axis guide 122 X-axis guide 130 Head part 131 Head plate 132 Jet head 133 First camera 134 Liquid crystal storage tank 135 Pump 136 Supply line 140 Drive part 150 Control part

Claims (5)

In a liquid crystal coating apparatus comprising: a stage that supports a substrate; a head unit that applies liquid crystal to the substrate on the stage unit while relatively moving with the stage; and a drive unit that relatively moves the stage and the head unit.
An imaging device for imaging the state of the liquid crystal applied by the head unit;
Based on the image picked up by the image pickup device, it is determined whether or not the applied liquid crystal is appropriate, and the drive unit is controlled to adjust the speed of the relative movement based on the determination of suitability. A liquid crystal coating apparatus comprising: a control unit.   The liquid crystal coating apparatus according to claim 1, wherein the imaging device includes a first camera mounted on the head unit.   The liquid crystal coating apparatus according to claim 1, further comprising a purge plate that is arranged in parallel with the substrate and is supported by the stage and to which a test liquid crystal coating is applied.   The liquid crystal coating apparatus according to claim 3, wherein the imaging apparatus includes a second camera that is mounted on the stage and images a state of liquid crystal applied to the purge plate. The stage includes a transfer guide coupled to the second camera to allow the second camera to reciprocate along the purge plate, and a driving unit that drives reciprocating transfer of the second camera. The liquid crystal coating apparatus according to claim 4, wherein the liquid crystal coating apparatus is characterized.

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