KR20140032272A - Apparatus and method of forming alignment layer - Google Patents

Apparatus and method of forming alignment layer Download PDF

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Publication number
KR20140032272A
KR20140032272A KR1020120098968A KR20120098968A KR20140032272A KR 20140032272 A KR20140032272 A KR 20140032272A KR 1020120098968 A KR1020120098968 A KR 1020120098968A KR 20120098968 A KR20120098968 A KR 20120098968A KR 20140032272 A KR20140032272 A KR 20140032272A
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South Korea
Prior art keywords
discharge
nozzle
alignment
alignment liquid
pattern
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KR1020120098968A
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Korean (ko)
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이승후
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엘지디스플레이 주식회사
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Priority to KR1020120098968A priority Critical patent/KR20140032272A/en
Publication of KR20140032272A publication Critical patent/KR20140032272A/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/145—Arrangement thereof
    • B41J2/155—Arrangement thereof for line printing
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/1303—Apparatus specially adapted to the manufacture of LCDs
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2202/00—Embodiments of or processes related to ink-jet or thermal heads
    • B41J2202/01—Embodiments of or processes related to ink-jet heads

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Mathematical Physics (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Liquid Crystal (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)

Abstract

The present invention relates to a method for forming an alignment layer to form a uniform alignment layer. The method for forming an alignment layer comprises the steps of: outputting a discharging pattern of alignment liquid to be loaded on a substrate; comparing an actual discharging amount and a set detecting amount to detect an error of a discharging amount; adjusting the number of nozzles opened in the area where the error occurs and a discharging frequency of the opened nozzles to correct the error of the discharging pattern; detecting non-discharging nozzles which cannot discharge; adjusting the nozzles opened in the area surrounding an abnormal nozzle and the discharging frequency of the nozzle to correct the discharging pattern; discharging the alignment liquid to be coated according to the corrected discharging pattern; and curing the coated alignment liquid. [Reference numerals] (AA,CC) No; (BB,DD) Yes; (S201) Input a thickness of a target alignment layer; (S202) Output a discharging amount and a discharging pattern based on various information; (S203) Discharge; (S204) The discharging amount is different ?; (S205) Adjust the number of a nozzle being opened and adjust the frequency discharged from the opened nozzle; (S206) Abnormal nozzle exists?; (S207) Adjust the nozzle around the abnormal nozzle; (S208) Correct dithering

Description

Alignment film forming apparatus and forming method {APPARATUS AND METHOD OF FORMING ALIGNMENT LAYER}

The present invention relates to an alignment film forming apparatus and a method for forming the same, and in particular, by identifying the position of an abnormally unejected nozzle in an inkjet method and adjusting an amount of the alignment liquid discharged from another nozzle, an alignment film having a uniform thickness can be formed. An alignment film forming apparatus and a forming method.

Recently, with the development of various portable electronic devices such as mobile phones, PDAs, notebook computers, and facing TVs, the demand for flat panel display devices for light and small sized devices is gradually increasing. It is becoming. Such flat panel displays are being actively researched, such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), FED (Field Emission Display), VFD (Vacuum Fluorescent Display), but mass production technology, ease of driving means, Background Art Liquid crystal display devices (LCDs) are in the spotlight for reasons of implementation and large scale.

1 schematically illustrates a cross section of a general liquid crystal display device. The liquid crystal display element 1 is constituted by a lower substrate 5 and an upper substrate 3 and a liquid crystal layer 7 formed between the lower substrate 5 and the upper substrate 3 . Although the lower substrate 5 is a driving element array substrate, although not shown in the drawing, a plurality of pixels are formed on the lower substrate 5, and each pixel is driven such as a thin film transistor. An element is formed. The upper substrate 3 is a color filter substrate, and a color filter layer for realizing color is formed. A pixel electrode and a common electrode are formed on the lower substrate 5 and the upper substrate 3, respectively, and an alignment film for aligning the liquid crystal molecules of the liquid crystal layer 7 is applied.

The lower substrate 5 and the upper substrate 3 are bonded by a sealing material 9, and a liquid crystal layer 7 is formed therebetween, and is driven by a driving element formed on the lower substrate 5. Information is displayed by controlling the amount of light passing through the liquid crystal layer by driving the liquid crystal molecules.

The manufacturing process of the liquid crystal display device can be largely divided into a driving element array substrate process of forming a driving element on the lower substrate 5, a color filter substrate process of forming a color filter on the upper substrate 3, and a cell process. However, the process of the liquid crystal display will be described with reference to FIG. 2.

First, a plurality of gate lines and data lines arranged on the lower substrate 5 to define a pixel region are formed by a driving element array process, and the gate line and the data are formed in each of the pixel regions. A thin film transistor which is a driving element connected to the line is formed (S101). In addition, a pixel electrode connected to the thin film transistor through the driving element array process and driving the liquid crystal layer as a signal is applied through the thin film transistor is formed.

In addition, the upper substrate 3 is formed with a color filter layer and a common electrode of R, G, B to implement the color by the color filter process (S104).

Subsequently, an alignment layer is applied to the upper substrate 3 and the lower substrate 5, respectively, and then the alignment control force or surface fixing force (ie, the liquid crystal molecules of the liquid crystal layer formed between the upper substrate 3 and the lower substrate 5). In order to provide a pretilt angle and an orientation direction, the alignment layer is rubbed (S102 and S105). Thereafter, liquid crystal is dropped onto the set area of the lower substrate 5 and the sealing material 9 is applied to the outer portion of the upper substrate 3, and then the pressure is applied to the lower substrate 5 and the upper substrate 3. To be added (S103, S106, S107). The liquid crystal dropped on the lower substrate is uniformly spread over the entire substrates 3 and 5 as the lower substrate 5 and the upper substrate 3 are bonded together to form a liquid crystal layer.

On the other hand, the lower substrate 5 and the upper substrate 3 are made of a glass substrate having a large area. In other words, a plurality of panel regions are formed on the glass substrate of a large area, and a TFT and a color filter layer serving as driving elements are formed in each of the panel regions, so that the glass substrates are cut to produce a single liquid crystal panel. The process is separated into a unit liquid crystal panel (S108). Thereafter, the liquid crystal display device is manufactured by inspecting each separated liquid crystal panel (S109).

The liquid crystal display device manufactured through the above process utilizes the electro-optic effect of the liquid crystal. The electro-optic effect is determined by the anisotropy of the liquid crystal itself and the molecular arrangement state of the liquid crystal. It will greatly affect the stabilization of the display quality of the liquid crystal display device.

Therefore, the alignment film forming process for more effectively aligning the liquid crystal molecules is very important in relation to the image quality characteristics in the liquid crystal cell process.

3A illustrates a conventional alignment film forming method using an inkjet method. As shown in the drawing, conventional alignment film formation is performed by discharging an alignment liquid onto a substrate using a plurality of heads having a plurality of nozzles formed thereon.

As shown in FIG. 3A, the alignment film forming apparatus is an inkjet ejecting apparatus, which includes an inkjet head portion 20 for directly discharging the alignment liquid onto the substrate 3 and an alignment liquid supply portion for supplying the alignment liquid to the inkjet head portion 20. (Not shown) and a connection wiring portion (not shown) for mechanically connecting the inkjet head portion 20 and the alignment liquid supply portion (not shown).

As shown in FIG. 3B, the head portion 20 includes two head portions of the first head portion 20a and the second head portion 20b, and includes the first head portion 20a and the second head portion ( 20b) A plurality of nozzles 21a and 21b are formed on the lower surface thereof, and the alignment liquid supplied from the alignment liquid supply part to the head portions 20a and 20b is discharged through the nozzles 21a and 21b.

When discharging the alignment liquid, the first head portion 20a opens the odd-numbered nozzles to discharge the alignment liquid, but even-numbered nozzles are closed to discharge the alignment liquid, and the second head portion 20b uses the odd-numbered nozzles. The even-numbered nozzle is opened to discharge the alignment liquid without closing and discharging the alignment liquid. That is, the alignment liquid is zigzagly discharged from the nozzles 21a and 21b of the two head portions 20a and 20b to form an alignment film on the substrate.

As described above, in the conventional alignment film forming apparatus, two head portions 20a and 20b are provided and the zigzag discharge of the alignment liquid from each nozzle 21a and 21b is performed to maintain the discharge interval of the discharged alignment film at a constant distance. to be. For example, when the alignment liquid is discharged to one head, an amount larger than the set amount is discharged when the gap between the nozzles is small, and an amount less than the set amount is discharged when the gap between the nozzles is wide to form an alignment film having various thicknesses. It cannot be formed.

However, by providing the two head portions 20a and 20b, it is possible to maintain an appropriate ejection interval so as to eject a desired amount of the alignment liquid.

However, such an alignment film forming apparatus has the following problems. As shown in FIG. 3B, the supply pipes 23a and 23b are connected to both side surfaces of the head portions 20a and 20b, respectively, so that the alignment liquid is supplied into the head portions 20a and 20b from the alignment liquid supply portion not shown.

Therefore, when driving the head portions 20a and 20b to discharge the alignment liquid, the discharge amount of the alignment liquid discharged from the regions where the alignment liquid is supplied, i.e., both sides of the head portions 20a and 20b, is the center of the head portions 20a and 20b. Is larger than the discharge amount of the alignment liquid discharged from the.

That is, as shown in FIG. 4, the discharge amount of the alignment liquid discharged increases from the central regions of the head portions 20a and 20b to the outer region, so that the alignment layer moves from the side of the substrate toward the center when the actual alignment layer is formed. The thickness of the film is reduced, so that an uneven thickness of the alignment film is formed over the entire substrate, and the thickness of the non-uniform alignment film is a fatal cause that causes the liquid crystal display device to be defective, such as spots on the image when the liquid crystal display device is completed. Becomes

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an alignment film capable of always forming an alignment film having a uniform thickness by inspecting a discharge error of an alignment liquid and an abnormal non-ejection nozzle and calculating a discharge pattern of the alignment liquid based on the result. It is an object to provide a forming apparatus and a manufacturing method thereof.

In order to achieve the above object, the alignment film forming apparatus according to the present invention comprises a stage on which a substrate is loaded; A head part disposed on one side of the stage and having a plurality of nozzles formed on a lower surface thereof to discharge the alignment liquid supplied therein to the substrate through the nozzle while moving the upper part of the stage; A weight measuring unit which measures a discharge amount of the alignment liquid discharged from the head unit by measuring a weight of the alignment liquid discharged from the head unit; A nozzle inspection unit which photographs a discharge dot discharged from the head unit and determines whether the nozzle of the head unit is normally operated; And a control unit for calculating a discharge pattern based on various kinds of information, correcting the discharge amount and the discharge pattern of the alignment liquid based on the information input from the weighing unit and the nozzle inspection unit, and driving the head unit to discharge the alignment liquid to the substrate. .

The control unit may include a discharge pattern calculator configured to calculate a discharge amount and a single discharge amount of the alignment liquid to be dropped onto the substrate, and calculate a discharge pattern formed on the substrate based on the discharge amount; A discharge amount error detection unit for detecting a discharge amount error by comparing the actual discharge amount input by the weighing unit with a set detection amount; A non-ejection nozzle inspection unit that detects a non-ejection nozzle whose outlet is blocked based on an image of the test discharge input from the nozzle inspection unit; A discharge pattern correcting unit correcting the discharge pattern based on the error of the discharge amount detected by the discharge amount error detecting unit and the abnormal discharge nozzle information checked by the non-ejecting nozzle inspection unit; And a head driver driving the head unit to discharge the alignment liquid along the corrected discharge pattern, wherein the discharge pattern corrector corrects the discharge pattern by adjusting the number of open nozzles and the number of discharges of the open nozzles.

In addition, the alignment film forming method according to the present invention includes the steps of calculating the discharge pattern of the alignment liquid to be dropped onto the substrate; Detecting the discharge amount error by comparing the actual discharge amount with a set detection amount; Correcting the error of the ejection pattern by adjusting the number of open nozzles and the number of ejections of the open nozzles in an area where an error occurs; Detecting a non-eject nozzle that cannot be discharged; Correcting the error of the discharge pattern by adjusting the number of ejection of the nozzle and the nozzle being opened in the region around the abnormal nozzle; Discharging the alignment liquid along the corrected discharge pattern to apply the alignment liquid; And curing the applied alignment liquid.

The calculating of the discharge pattern includes calculating the discharge amount and the single discharge amount of the alignment liquid to be dropped onto the substrate based on the thickness of the alignment layer, the characteristics of the alignment liquid, the size of the panel, and the display mode of the panel, and forming the discharge pattern based on the discharge pattern. Wherein the inspecting the non-ejected nozzle comprises: testing the nozzle; Photographing the test-discharged dots; And detecting no discharge lines based on the captured image.

Further, the corrected ejection pattern distributes dots of the ejection pattern by dithering correction. The dithering correction classifies the ejection pattern into a plurality of groups consisting of a plurality of rows, and then, each of the groups by a distance set along the column direction. Each step consists of moving in different directions.

In the present invention, when an error occurs in the discharge amount of the alignment liquid, the amount of the alignment liquid is always discharged by adjusting the number of nozzles opened in the head and the number of times the open nozzles are actually discharged. In addition, when a part of the nozzle of the head portion is blocked by the residue of the alignment liquid or the like, the number of openings of other nozzles around the non-ejecting nozzle or the number of openings of the ladle is increased, thereby correcting the discharge amount of the alignment liquid not discharged by the non-ejecting nozzle. An alignment liquid having a uniform thickness is applied onto the substrate.

In the present invention, when a large amount of the discharging dot of the alignment liquid is formed in a specific region by the correction of the discharge amount, it is impossible to apply the uniform liquid on the substrate as a whole. Therefore, dithering correction is performed to discharge all of the discharge dots gathered. By dispersing the pattern and arranging the dots relatively uniformly, an alignment film having a more uniform thickness can be formed.

1 is a sectional view of a general liquid crystal display device.
2 is a flow chart showing a conventional method of manufacturing a liquid crystal display element;
3 is a view showing the structure of a conventional alignment film forming apparatus.
4 is a view showing a discharge amount error according to a nozzle position in a conventional alignment film forming apparatus.
5 is a view showing the structure of an alignment film forming apparatus according to the present invention.
6A and 6B show the structure of the head portion of the alignment film forming apparatus.
Fig. 7 is a block diagram showing the structure of a control unit of the alignment film forming apparatus of the present invention.
8 is a flowchart showing a method for forming an alignment film according to the present invention.
9A to 9D are views showing the opening, closing, and discharge patterns of the nozzles of the head drive unit.

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

In the present invention, when an error occurs in the discharge amount of the alignment liquid, in order to correct this, not only the number of nozzles opened in the head part but also the number of discharges actually discharged to the opened nozzles are adjusted. Particularly, in the present invention, when a part of the nozzle of the head portion is blocked by the residue of the alignment liquid or the like, the nozzle is discharged by increasing the number of opening or opening of other nozzles around the non-ejecting nozzle so that the alignment liquid of uniform thickness is always applied on the substrate. .

In addition, in the present invention, when many discharge dots of the alignment liquid are formed in a specific region by the correction of the discharge amount, it is impossible to apply the uniform alignment liquid as a whole on the substrate. Therefore, dithering correction is performed to discharge all of the discharge dots collected. Disperse the pattern and arrange dots relatively uniformly.

5 is a view showing the structure of the alignment film forming apparatus 100 according to the present invention.

As shown in FIG. 5, the alignment layer forming apparatus 100 of the present invention includes a frame 130, a stage 132 disposed on the frame 130, and a substrate loaded from the outside, and the stage 132. A head part 120 disposed at one side of the head and discharging the alignment liquid supplied therein to the substrate loaded on the stage 132 while moving the upper portion of the stage 132 along the y-direction, and an end portion of the frame 130. A weight measuring unit 134 disposed at the end of the frame 130 to measure the amount of the alignment liquid discharged from the head unit 120 to measure the discharge amount of the alignment liquid discharged from the head unit 120. The nozzle inspection unit 136 which determines whether the nozzle of the head unit 120 operates normally by photographing a discharge dot discharged from the head unit 120 and the head unit 120 is controlled to discharge the alignment liquid. The discharge pattern is calculated based on various kinds of information, and the weight measuring unit 134 is used. And a controller for correcting the discharge amount and the discharge pattern of the alignment liquid based on the information input from the nozzle inspection unit 136.

Although not shown in the drawing, a guide is installed in the frame 130 so that the head 120 moves from one end to the other end of the frame 130 along the guide. At this time, the head portion 120 is moved by a driving means such as a motor, the alignment liquid is discharged from the head portion 120 on the substrate while moving on the substrate loaded on the stage 132.

6A is a view illustrating the head 120 in detail. In the present invention, the number of the head portion varies depending on the thickness of the liquid crystal display element on which the alignment layer is formed, etc. For example, three or more head portions may be used when manufacturing a large liquid crystal display element. However, in the drawings, only the structure in which two heads 120a and 120b are arranged for the sake of simplicity is illustrated, but the present invention is not limited to these two heads.

 As shown in FIG. 6A, the head part 120 includes a first head part 120a and a second head part 120b disposed at predetermined intervals, and the two head parts 120a and 120b are formed. The alignment liquid is discharged on the substrate 103 disposed on the stage 132 while moving from one side to the other side in the y-direction.

As shown in FIG. 6B, the first head part 120a and the second head part 120b include a plurality of first nozzles 121a and second nozzles 121b, respectively. At this time, the length of the first head portion 120a and the second head portion 120b and the first nozzle 121a and the second nozzle formed on the first head portion 120a and the second head portion 120b, respectively. The number of 121b varies depending on the size of the liquid crystal display element on which the alignment film is formed. The plurality of first nozzles 121a and the second nozzles 121b respectively formed on the first head portion 120a and the second head portion 120b may operate as a single unit, or a large-area agent. In the case of the first head portion 120a and the second head portion 120b, the plurality of first nozzles 121a and the second nozzles 121b operate as one group, and a plurality of such groups are formed. In this way, by controlling the nozzles by grouping the plurality of nozzles in groups, it is possible to easily and partially control the amount of the ejection liquid.

Although the first head portion 120a and the second head portion 120b may continuously discharge the alignment liquid while continuously moving on the substrate 103, the first head portion 120a and the second head portion 120b may be discharged. ) Is discharged in a dot shape in the state of stopping after moving a certain distance, and after moving a certain distance again, the alignment liquid is discharged in a dot shape. Substantially, the first head portion 120a and the second head portion 120b discharge the alignment liquid along a predetermined discharge pattern (a shape formed by a plurality of alignment liquid discharge dots).

As shown in FIG. 5, the weighing unit 134 is installed at one end region of the frame 130. Although not shown in the drawing, the weighing unit 134 is provided with a scale for measuring the weight of the container in which the alignment liquid is discharged from the nozzle of the head unit 120 and the container containing the alignment liquid. The weight of the alignment liquid discharged from a nozzle is measured. That is, after the first head portion 120a and the second head portion 120b move to the end region of the frame 134 along the guide (not shown), the alignment liquid is discharged into the container and the weight is measured.

At this time, since the discharge amount of one dot is very small, the container is discharged a predetermined number of times, for example, 100 dots and the weight is measured, and then the average weight of one dot is calculated by dividing the measured weight by 100 times. (I.e., 1 dot) the discharge amount is measured. The discharge amount is measured for both the first nozzle 121a and the second nozzle 121b formed in the first head portion 120a and the second head portion 120b. That is, while the weighing unit 134 moves along the x-direction by a moving means such as a motor, the alignment liquid is discharged from each nozzle to measure the discharge amount of each nozzle.

The nozzle inspection unit 136 inspects whether the first nozzle 121a and the second nozzle 121b formed in the first head part 120a and the second head part 120b operate normally. Typically, since the alignment liquid is a liquid material having a viscosity, a part of the alignment liquid remains in the nozzle when discharged through the first nozzle 121a and the second nozzle 121b. Nozzle is blocked.

If the nozzle is clogged and the nozzle does not operate normally, discharge of the alignment liquid through the nozzle does not occur. Therefore, when the alignment liquid is discharged according to the set discharge pattern, the discharge does not occur in the same manner as the actual discharge pattern. Application of the alignment film of thickness becomes impossible.

The nozzle inspection unit 136 detects the non-ejected nozzle by inspecting that the nozzle is blocked and operating abnormally. Although not shown in the drawing, a dummy substrate is formed on the nozzle inspection unit 136 with a transparent material such as glass or plastic, so that the first nozzle 121a and the second head 120a and the second head 120b are formed. The nozzle 121b discharges the alignment liquid on the dummy substrate once. In this case, a camera 138 is installed at the lower portion of the dummy substrate to photograph the test discharged alignment liquid, and analyze the photographed image to inspect the clogged nozzle.

The setting of the amount of the alignment liquid discharged to the substrate 103, the setting of the discharge pattern, the correction of the discharged amount, and the like are made by the controller.

7 is a block diagram showing the structure of the controller 180 of the alignment film forming apparatus according to the present invention.

As shown in FIG. 7, the controller 180 calculates a discharge amount of an alignment liquid to be dropped onto a substrate and a discharge amount of one time (one dot), and calculates a discharge pattern formed on the substrate based on the discharge pattern calculator 181. And a discharge amount error detection unit 183 for detecting a discharge amount error by detecting the actual discharge amount and comparing with the set detection amount by inputting the weight of the discharge amount measured by the weighing unit 134, and a test input from the nozzle inspection unit 136 The non-ejection nozzle inspection unit 184 detects a non-ejection nozzle that cannot be ejected based on the image of the ejection, and the error of the ejection amount detected by the ejection amount error detection unit 183 and the abnormal ejection inspected by the non-ejection nozzle inspection unit 184. The discharge pattern correction unit 186 corrects the discharge pattern calculated by the discharge pattern calculation unit 181 based on the discharge nozzle information, and the head pattern 120a and 120b are driven to correct the discharge pattern correction unit 186. Discharge It consists of the head drive part 188 which discharges an alignment liquid along a pattern.

The discharge pattern calculator 181 calculates the discharge amount of the alignment liquid to be dropped onto the substrate in consideration of the size, display mode, thickness of the alignment layer, characteristics of the alignment liquid, etc. of the liquid crystal display device to be manufactured, and based on the discharge amount To calculate the discharge pattern. In general, since the shapes of electrodes (for example, gate lines and data lines) formed on the substrate vary according to the display mode of the liquid crystal display device, the flow direction of the alignment liquid varies when the alignment liquid is discharged onto the substrate. Of course, the viscosity of the alignment liquid is not large, and thus the degree of flow of the alignment liquid is not relatively large compared with that of other liquid materials, but it affects the flow direction or the spreading direction of the alignment liquid according to the shape of the electrode. The shape of the discharge pattern is changed according to the display mode.

Similarly, the characteristics of the alignment liquid, for example, the viscosity of the alignment liquid and the like also affect the flow direction or the spreading direction of the alignment liquid, so that the shape of the discharge pattern varies according to the characteristics of the alignment liquid.

The discharge amount error detecting unit 183 inputs the actual discharge amount of each nozzle measured by the weight measuring unit 134, and detects an error of the discharge amount by comparing the measured discharge amount with the set discharge amount. As shown in FIG. 4, since the discharge amount discharged from the nozzle increases from the center of the substrate to the outer region, the discharge amount variation in the center and the outer portion of the substrate is increased. That is, the error of the discharge amount hardly occurs in the outer region of the substrate, and increases with the center region. Of course, this criterion differs at which point the set discharge amount and the actual measured discharge amount are designed identically. That is, in the case where the discharge amount measured in the center region is almost the same as the set discharge amount, the error of the discharge amount hardly occurs in the center region of the substrate and increases toward the outer region, and the discharge amount measured between the center region and the outer region of the substrate is set. When the discharge amount is almost equal to the discharge amount, the error of the discharge amount hardly occurs between the center region and the outer region of the substrate, and increases from the corresponding region to the outer region and the central region.

In the present invention, although the set discharge amount and the measured discharge amount are designed to be the same in the outermost region of the substrate, and the error of the discharge amount becomes larger toward the center region, it may be designed differently as necessary.

The non-ejection nozzle inspecting unit 184 analyzes an image of the test ejection photographed by the nozzle inspecting unit 136 and inspects an abnormal non-ejecting nozzle. In the nozzle inspection unit 136, the alignment liquid is discharged once to the dummy substrate while all the nozzles 121a and 121b of the first head part 120a and the second head part 120b are opened, and the discharge is performed by a camera. The alignment liquids of all the dots thus obtained are photographed and input to the non-eject nozzle inspection unit 184. The non-ejection nozzle inspection unit 184 transmits and stores the positional information about the nozzles 121a and 121b of the first head portion 120a and the second head portion 120b to which the test ejection proceeds, and analyzes the photographed image. By comparing the coordinates of the region (that is, the position of the ejecting nozzle) in which the specific shape is not photographed with the position information of the stored nozzles 121a and 121b, the ejecting nozzle is checked.

The discharge pattern correcting unit 186 receives not only the discharge pattern calculated by the discharge pattern calculator 181 but also the error information of the discharge amount detected by the discharge amount error detection unit 183 and the unexhausted nozzle inspection unit 184. Discharge nozzle information is input.

The discharge pattern correction unit 186 corrects the discharge pattern based on the error information of the discharge amount input from the discharge amount error detection unit 183. That is, in the outer region of the substrate having little discharge amount error, the calculated discharge pattern is applied as it is, and the number of dottings in which the alignment liquid is discharged is increased toward the center region so that the alignment layer is coated with a uniform thickness throughout the substrate.

As will be described later, this increase in the number of dots is achieved by increasing the number of open nozzles by opening the closed nozzles, and adjusting the number of actual ejections from the open nozzles.

In addition, the discharge pattern correction unit 186 corrects the discharge pattern already corrected on the basis of the non-eject nozzle information input from the non-eject nozzle inspection unit 184. That is, when the nozzle at a specific position does not work abnormally, by opening other closed nozzles around, by adjusting the number of discharge through the open nozzle to compensate the amount of the alignment liquid as not discharged from the non-ejection nozzle to the entire substrate An alignment film of uniform thickness is applied over.

The discharge pattern correction unit 186 performs dithering correction. Dithering correction corrects the discharge pattern by moving the corrected discharge pattern in matrix units based on the discharge amount error information and the undischarge nozzle information. That is, when the nozzle in the column direction specific to the discharge pattern corrected on the basis of the discharge amount error information and the non-eject nozzle information is opened much more than the nozzles in the other column direction, the area of the substrate corresponding to this column direction In comparison, a much larger amount of alignment liquid is added. Of course, the alignment liquid has a certain spreading property, and the alignment liquid dropped onto the substrate from the nozzle in the row spreads to another region, so that the amount of the alignment liquid in the region decreases, but since the alignment liquid has a certain viscosity, the degree of spreading is limited. Therefore, the thickness of the alignment layer becomes larger in the corresponding region or in the peripheral region thereof than in the other region, and when the liquid crystal display device is manufactured, staining occurs in this region.

The ejection pattern correcting unit 186 performs dithering correction to move the corrected ejection pattern in units of rows so as to disperse the dotting gathered along a specific column around so that a large amount of alignment liquid is not ejected to a specific region.

The head driver 188 drives the first head part 120a and the second head part 120b to discharge the alignment liquid according to the calculated and corrected discharge pattern.

Hereinafter, a method of forming the actual alignment film using the alignment film forming apparatus having the above structure will be described in detail.

8 is a flowchart illustrating a method of forming an alignment layer according to the present invention, and FIGS. 9A to 9D are views illustrating whether the nozzle of the head unit 120 is actually opened or closed and a discharge pattern discharged to a substrate.

First, as shown in Figure 8, after setting the thickness of the alignment film of the liquid crystal display device to be produced (S201), the substrate in consideration of the size of the liquid crystal display device, the display mode, the thickness of the alignment film, the characteristics of the alignment liquid, etc. The discharge amount of the alignment liquid to be added to the liquid is calculated, and the discharge pattern of the alignment liquid discharged from the head unit 120 is calculated based on the discharge amount (S202).

The discharge pattern calculated in FIG. 9A is shown. As shown in FIG. 9A, in the ejection pattern, the first nozzle 121a of the first head part 120a is odd-numbered, the even number is closed, and the second nozzle 121b of the second head part 120b is closed. Is odd-numbered closed and even-numbered opened. That is, since the nozzles of the first head portion 120a and the second head portion 120b are zigzag-opened to each other, the nozzle pattern is formed in the substrate 103 by alternately forming dot and mid-dot regions in a matrix form.

Subsequently, after loading the substrate on the stage 132, the first head portion 120a and the second head portion 120b are driven to move the upper portion of the substrate to the first head portion 120a and the second head portion 120b. (A), the alignment liquid is discharged and the alignment liquid is discharged onto the substrate along the discharge pattern (S203). The alignment liquid is discharged in the form of dots on the substrate and is spread by the viscosity of the alignment liquid to meet the alignment liquid of other dots, so that a uniform thickness is applied to the entire substrate.

Thereafter, the weight of the discharge amount measured by the weighing unit 134 is input to detect the actual discharge amount, and it is determined whether there is an error in the discharge amount by comparing with the actually set detection amount (S204).

If there is no error in the discharge amount, since the set amount of the alignment liquid is discharged, the discharge proceeds continuously without further correction, and if the error occurs in the discharge amount, the discharge pattern is corrected (S205).

Since the alignment liquid supplied to the first head portion 120a and the second head portion 120b from the external alignment liquid supply portion is supplied through both end portions of the first head portion 120a and the second head portion 120b. In addition, the amount of the alignment liquid remaining in the end regions of the first head portion 120a and the second head portion 120b is greater than that of the central region, and the pressure applied to the alignment liquid is also greater than that of the central region. Therefore, as shown in FIG. 9A, the error of the discharge amount increases from the outer region of the substrate to the center region as shown in the graph.

The error of the discharge amount depends on the structure of the alignment film forming apparatus and the like. For example, when the alignment liquid is supplied from the alignment liquid supplying portion to the center region of the first head portion 120a and the second head portion 120b, the center of the first head portion 120a and the second head portion 120b is provided. Since the amount of the alignment liquid remaining in the area is larger than the other area and the pressure of the alignment liquid in the center area is larger than the other area, the error graph of the discharge amount will be convex in the center area of the nozzle position, and the discharge is corrected in the discharge amount. The pattern will also be calculated according to this discharge amount error graph.

Correction of the discharge amount is made by increasing the number of open nozzles in the area corresponding to the region with a high error and adjusting the number of discharges actually discharged through the open nozzles.

As shown in FIG. 9B, in the nozzle corresponding to the region where the error of the discharge amount occurs, a part of the nozzle that is closed at the time of calculating the initial discharge pattern is opened and the alignment liquid is discharged through the nozzle to correct the discharge amount error. As shown in the error graph of the error, the error becomes more severe from the outer region to the center region, so that the number of openings of the error correction nozzles increases from the outside of the first head portion 120a and the second head portion 120b toward the center region. The discharge amount of the alignment liquid for error correction increases as it goes to the center area. In the figure, the portion indicated by the arrow in the upward direction is a nozzle which is originally designed to be closed in the second head portion 120b to open for discharge amount error correction.

On the other hand, correction of the discharge amount error is not performed by adjusting only the number of nozzles to be opened. If the nozzle is always discharged by opening the open nozzle to correct the error of the discharge amount, the nozzle may be larger than the actual error amount of the discharge amount of the alignment liquid in this area, so the open nozzle is always opened to correct the error of the discharge amount. Instead of adjusting the number of openings appropriately, the error can be corrected accurately.

In FIG. 9B, the discharge pattern in which the actual number of discharges of the nozzle in which the area indicated by the lower arrow is opened is controlled is controlled. As shown in FIG. 9B, the number of discharges from the open nozzle 121b (ie, the error correction nozzle) toward the center area, that is, the number of dotting times increases, thereby appropriately correcting the discharge error.

As illustrated in FIG. 8, after correcting the discharge error, it is checked whether there is a non-ejection nozzle whose outlet is blocked by an abnormal nozzle, that is, an alignment liquid residue or the like (S206).

If there is no non-ejection nozzle, the alignment liquid continues to proceed as with the corrected ejection pattern, and when the non-ejection nozzle is detected, the ejection pattern is corrected again (S207).

As shown in Fig. 9C, when a part of the nozzle to which the alignment liquid is to be discharged is clogged (nozzle indicated in black in the drawing), the area of the discharge pattern corresponding to this nozzle is not discharged at all so that no discharge dot exists. Therefore, the thickness of the alignment film in this area is different from the thickness of the alignment film in other areas.

The discharge pattern correction unit 186 increases the number of open nozzles by changing the nozzle state around the abnormal nozzle from the closed state to the open state in order to correct the deviation of the discharge amount of the undischarged area by the non-eject nozzle. The number of discharges from the discharged nozzle is adjusted. 9C is a discharge pattern in which a row of the discharge patterns indicated by a, b, c, and d open nozzles and control the number of discharges thereof, compared with FIG. 9B, in which the discharge dots are not generated at all by an abnormal nozzle. It can be seen that more dots are formed in the.

In the drawing, the correction for the discharge error and the error due to the abnormal nozzle are corrected sequentially, but two steps of correction may be performed at the same time. That is, the discharge pattern can be corrected at once by the information on the discharge error and the information on the abnormal nozzle.

After correcting the error due to the abnormal nozzle as described above, dithering correction is performed (S208).

Among the discharge patterns shown in FIG. 9C, the columns indicated by a, b, c, and d have more dots in which the alignment liquid is discharged compared to other columns. Therefore, when the actual alignment liquid is discharged, the thickness of the alignment film in this area becomes larger than the thickness of other areas, making it impossible to form an alignment film of uniform thickness.

Dithering correction is to correct the discharge pattern by moving it in matrix units. For example, in the case of an ejection pattern consisting of N rows and M columns, the ejection pattern is corrected by moving the n rows to the left or the right in units of m columns.

9D is a diagram showing some examples of such dithering corrections. In FIG. 9D, a discharge pattern is formed of 12 rows and 35 columns, and four rows of the 12 rows are classified into one group. The first four groups G1 are moved by three columns in the left direction, and the three rows of discharge patterns are designed to move to areas where the discharge patterns are emptied by the movement. Also, the second group G1 does not move, and the third group G3 moves by three columns in the right direction. Similarly, the three rows of ejection patterns are filled in the areas vacated by the movement.

The dithering correction is performed by the discharge pattern correcting unit 186. The dots of the a ', b', c ', and d' columns of the discharge pattern dithered in FIG. 9D are a, b, c, and d shown in FIG. 9C. It can be seen that the dots are dispersed in the dithered ejection pattern compared to the dot of the column. Although the amount of dots discharged to the substrate, that is, the total discharge amount of the alignment liquid discharged to the substrate is the same in the discharge pattern shown in FIG. 9C or the discharge pattern shown in FIG. 9D, the dithered discharge pattern shown in FIG. This means that more dots are jetted than the discharge pattern shown in FIG. 9C, and thus, when the actual alignment liquid is discharged to the substrate, an alignment film having a more uniform thickness can be formed.

In the drawing, four rows of the discharge pattern are classified into one group and then moved by three columns for the dither correction. However, the rows forming the group can be set variously according to various data such as the size of the liquid crystal display device. You can also vary the distance you travel.

In addition, although the first group G1 and the third group G3 move in opposite directions and do not move the second group G2 in the drawing, the second group G2 is opposite to the first group G1. Direction and the third group G3 may be moved in the opposite direction to the second group G2. In other words, you can move all groups or only some groups as needed.

When the discharge pattern is dither corrected, the head driver 188 drives the first head part 120a and the second head part 120b to discharge the alignment liquid along the calculated and dither corrected discharge pattern to apply the alignment layer. The alignment film is formed by applying heat or the like to the applied alignment film to cure the same.

As described above, in the present invention, the discharge pattern is formed in consideration of the discharge amount error of the alignment liquid, the presence of abnormal nozzles, the deviation of the alignment dot, and the like, and the alignment film is always discharged by discharging the alignment liquid according to the discharge pattern. It becomes possible.

On the other hand, in the above-described detailed description, an alignment film forming apparatus and a method of forming a specific structure are disclosed, but the present invention is not limited to such a specific structure and method, and a driving structure and which can be derived using the basic concept of the present invention. The method may also be applied.

120: head portion 121a, 12b: nozzle
132: stage 134: weighing unit
136: nozzle inspection unit 180: control unit
181: discharge pattern calculation unit 183: discharge amount error detection unit
184: non-ejection nozzle inspection unit 186: discharge pattern correction unit

Claims (12)

A stage on which the substrate is loaded;
A head part disposed on one side of the stage and having a plurality of nozzles formed on a lower surface thereof to discharge the alignment liquid supplied therein to the substrate through the nozzle while moving the upper part of the stage;
A weight measuring unit which measures a discharge amount of the alignment liquid discharged from the head unit by measuring a weight of the alignment liquid discharged from the head unit;
A nozzle inspection unit which photographs a discharge dot discharged from the head unit and determines whether the nozzle of the head unit is normally operated; And
An alignment film formed of a control unit that calculates a discharge pattern based on various information, corrects the discharge amount and the discharge pattern of the alignment liquid based on information input from the weighing unit and the nozzle inspection unit, and drives the head unit to discharge the alignment liquid to the substrate Device. The alignment film forming apparatus of claim 1, wherein the head parts are arranged in parallel with each other, and each head part includes a plurality of head parts each having a plurality of nozzles formed on a lower surface thereof. The alignment film forming apparatus according to claim 1, wherein the various pieces of information include the size of the liquid crystal display element, the display mode, the thickness of the alignment film, and the characteristics of the alignment liquid. The apparatus of claim 1,
A discharge pattern calculator configured to calculate a discharge amount and a single discharge amount of the alignment liquid to be dropped onto the substrate, and calculate a discharge pattern formed on the substrate based on the discharge amount;
A discharge amount error detection unit for detecting a discharge amount error by comparing the actual discharge amount input by the weighing unit with a set detection amount;
A non-ejection nozzle inspection unit that detects a non-ejection nozzle whose outlet is blocked based on an image of the test discharge input from the nozzle inspection unit;
A discharge pattern correcting unit correcting the discharge pattern based on the error of the discharge amount detected by the discharge amount error detecting unit and the abnormal discharge nozzle information checked by the non-ejecting nozzle inspection unit; And
An alignment film forming apparatus, comprising: a head portion driving portion for driving the head portion to eject the alignment liquid along a corrected discharge pattern. The alignment film forming apparatus of claim 4, wherein the discharge pattern correcting unit adjusts the number of open nozzles and the number of discharge times of the open nozzles. Calculating a discharge pattern of the alignment liquid to be dropped onto the substrate;
Detecting the discharge amount error by comparing the actual discharge amount with a set detection amount;
Correcting the error of the ejection pattern by adjusting the number of open nozzles and the number of ejections of the open nozzles in an area where an error occurs;
Detecting a non-eject nozzle that cannot be discharged;
Correcting the error of the discharge pattern by adjusting the number of ejection of the nozzle and the nozzle being opened in the region around the abnormal nozzle;
Discharging the alignment liquid along the corrected discharge pattern to apply the alignment liquid; And
An alignment film forming method comprising the step of curing the applied alignment liquid. The method of claim 6, wherein the calculating of the discharge pattern comprises calculating the discharge amount and the single discharge amount of the alignment liquid to be dropped onto the substrate based on the thickness of the alignment layer, the characteristics of the alignment liquid, the size of the panel, and the display mode of the panel. Forming an ejection pattern on the basis of the; 7. The method of claim 6, wherein the discharge amount error increases from the outer region of the substrate toward the center region. 10. The method of claim 8, wherein the number of nozzles discharged for error correction and the number of discharges of open nozzles increase from the outer region to the center region. The method of claim 6, wherein the inspecting the non-ejection nozzle,
Testing the nozzle;
Photographing the test-discharged dots; And
The method for forming an alignment film, characterized in that it comprises the step of detecting the non-ejection line based on the captured image. 7. The method of claim 6, further comprising dispersing dots of the discharge pattern by performing dithering correction on the corrected discharge pattern. 12. The method of claim 11, wherein the dithering correction comprises dividing the discharge pattern into a plurality of groups consisting of a plurality of rows, and then moving each group in a different direction by a distance set along the column direction. Alignment film formation method.
KR1020120098968A 2012-09-06 2012-09-06 Apparatus and method of forming alignment layer KR20140032272A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150141893A (en) * 2014-06-10 2015-12-21 캐논 가부시끼가이샤 Imprint apparatus, imprint method, and method of manufacturing article
US9740037B2 (en) 2014-09-15 2017-08-22 Samsung Display Co., Ltd. Liquid crystal display device
US10007149B2 (en) 2015-04-17 2018-06-26 Samsung Display Co., Ltd. Methods of manufacturing a photoalignment layer and a liquid crystal display

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150141893A (en) * 2014-06-10 2015-12-21 캐논 가부시끼가이샤 Imprint apparatus, imprint method, and method of manufacturing article
JP2015233101A (en) * 2014-06-10 2015-12-24 キヤノン株式会社 Imprint device, imprint method and method for manufacturing article
US10197910B2 (en) 2014-06-10 2019-02-05 Canon Kabushiki Kaisha Imprint apparatus, imprint method, and method of manufacturing article
US9740037B2 (en) 2014-09-15 2017-08-22 Samsung Display Co., Ltd. Liquid crystal display device
US10007149B2 (en) 2015-04-17 2018-06-26 Samsung Display Co., Ltd. Methods of manufacturing a photoalignment layer and a liquid crystal display

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