KR20060001665A - Apparatus for dispensing liquid crystal and method of dispensing liquid crystal using thereof - Google Patents

Abstract

The present invention is to accurately measure and correct the amount of liquid crystal dropping to always drop the correct amount of liquid crystal on the substrate, a container filled with the liquid crystal, a discharge pump for sucking and discharging the liquid crystal filled in the container, And a nozzle for dropping the liquid crystal discharged from the discharge pump onto the substrate, and a flowmeter for measuring the flow rate of the liquid crystal flowing out of the container and detecting the drop amount of the liquid crystal dropped on the substrate.

Liquid crystal dropping, dripping amount, flow meter, temperature, dripping correction

Description

Liquid crystal dropping device and liquid crystal dropping method {APPARATUS FOR DISPENSING LIQUID CRYSTAL AND METHOD OF DISPENSING LIQUID CRYSTAL USING THEREOF}

1 is a cross-sectional view of a general liquid crystal display device.

2 is a flowchart showing a conventional method for manufacturing a liquid crystal display device.

3 is a view showing liquid crystal injection of a conventional liquid crystal display device.

4 is a view showing a liquid crystal display device manufactured by the liquid crystal dropping method according to the present invention.

5 is a flowchart illustrating a method of manufacturing a liquid crystal display device by the liquid crystal dropping method.

6 is a view showing a basic concept of the liquid crystal dropping method.

7 is a perspective view showing the structure of the liquid crystal droplets according to the present invention.

8 is an exploded perspective view showing the structure of the liquid crystal droplets according to the present invention.

FIG. 9 is an enlarged view of region A of FIG. 8 and illustrates a structure in which a flowmeter is installed to be liquid crystal.

Figure 10a is a perspective view showing the structure of the liquid crystal discharge pump of the liquid crystal drop according to the present invention.

10B is an exploded perspective view showing the structure of a liquid crystal discharge pump.

11 is a view showing a state in which the liquid crystal discharge pump is fixed to the fixed portion.

12A to 12D are views showing the operation of the liquid crystal discharge pump.

13 is a view showing the structure of the liquid crystal discharge pump with a fixed angle increased.

14 is a block diagram showing the structure of a control unit of the liquid crystal dropping apparatus according to the present invention;

15 is a flowchart showing a liquid crystal dropping method by the liquid crystal dropping apparatus according to the present invention.

Explanation of symbols on main parts of drawing

120: liquid crystal drop 122: liquid crystal container

123: Case 128: Pin

131,133: motor 134: liquid crystal volume adjusting member

136: rotation axis 137: control lever

140: liquid crystal discharge pump 142: cylinder

145: piston 145a: groove

147: liquid crystal suction opening 148: liquid crystal discharge opening

149: fixing part 150: nozzle

154, 162 sensor 160 connector

190: flow meter 192: heater

194,196: temperature sensor 200: control unit

202: dripping amount setting unit 204: temperature difference detection unit

206: load detection unit 208: load compensation

210: motor drive unit 212: output unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal dropping device, and more particularly, to a liquid crystal dropping device and a liquid crystal dropping method capable of precisely dropping a precise amount of liquid crystal onto a substrate to prevent a defect from occurring in the liquid crystal display device.

Recently, with the development of various portable electronic devices such as mobile phones, PDAs, and notebook computers, there is a growing demand for flat panel display devices for light and thin applications. 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, Liquid crystal display devices (LCDs) are in the spotlight for reasons of implementation.

LCD is a device for displaying information on the screen using the refractive anisotropy of the liquid crystal. As shown in FIG. 1, the LCD 1 is composed of 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. The lower substrate 5 is a drive element array substrate. Although not shown in the figure, a plurality of pixels are formed on the lower substrate 5, and a driving element such as a thin film transistor (hereinafter referred to as TFT) is formed in each pixel. The upper substrate 3 is a color filter substrate, and a color filter layer for real color is formed. In addition, 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 liquid crystal molecules of the liquid crystal layer 7 is coated.

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 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, the pixel electrode is connected to the thin film transistor through the driving element array process to drive the liquid crystal layer as a signal is applied through the thin film transistor.

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). Subsequently, a spacer is disposed on the lower substrate 5 to maintain a constant cell gap, and a sealing material 9 is applied to an outer portion of the upper substrate 3, and then the lower substrate 5 is disposed. And the upper substrate 3 by applying pressure (S103, S106, S107).

On the other hand, the lower substrate 5 and the upper substrate 3 is made of a large area glass substrate. In other words, a plurality of panel regions are formed on a large area glass substrate, and a TFT and a color filter layer, which are driving elements, are formed in each of the panel regions. Must be processed (S108). Thereafter, the liquid crystal is injected into the liquid crystal panel processed as described above through the liquid crystal inlet, and the liquid crystal inlet is encapsulated to form a liquid crystal layer. Then, the liquid crystal display is manufactured by inspecting each liquid crystal panel (S109 and S110). .

The liquid crystal is injected through the liquid crystal inlet formed in the panel. At this time, the injection of the liquid crystal is made by the pressure difference. 3 shows an apparatus for injecting liquid crystal into the liquid crystal panel. As shown in FIG. 3, a container 12 filled with liquid crystal is provided in a vacuum chamber 10, and a liquid crystal panel 1 is positioned on an upper portion thereof. The vacuum chamber 10 is connected to a vacuum pump to maintain a set vacuum state. In addition, although not shown in the drawing, an apparatus for moving the liquid crystal panel is installed in the vacuum chamber 10 to move the liquid crystal panel 1 from the upper part of the container 12 to the container. 16) is brought into contact with the liquid crystal 14 (this method is referred to as a liquid crystal dipping injection method).

As described above, when nitrogen (N ₂ ) gas is supplied into the vacuum chamber 10 while the injection port 16 of the liquid crystal panel 1 is in contact with the liquid crystal 14, the vacuum degree of the chamber 10 is reduced. The liquid crystal 14 is injected into the panel 1 through the injection hole 16 by the pressure difference between the pressure inside the liquid crystal panel 1 and the vacuum chamber 10 and the liquid crystal is completely filled in the panel 1. The liquid crystal layer is formed by sealing the injection hole 16 with a sealing material (this method is called vacuum injection of liquid crystal).

However, the method of forming the liquid crystal layer by injecting liquid crystal through the injection hole 16 of the liquid crystal panel 1 in the vacuum chamber 10 as described above has the following problems.

First, the liquid crystal injection time to the panel 1 is long. In general, the distance between the driving element array substrate and the color filter substrate of the liquid crystal panel is very narrow, such as several μm, so that only a very small amount of liquid crystal is injected into the liquid crystal panel per unit time. For example, when manufacturing a liquid crystal panel of about 15 inches takes about 8 hours to completely inject the liquid crystal, the liquid crystal panel manufacturing process is lengthened by the long-term liquid crystal injection, the manufacturing efficiency is lowered.

Second, the liquid crystal consumption rate is high in the liquid crystal injection method as described above. Of the liquid crystals 14 filled in the container 12, the amount injected into the liquid crystal panel 1 is very small. Meanwhile, when the liquid crystal is exposed to the atmosphere or a specific gas, the liquid crystal not only deteriorates by reacting with the gas, but also deteriorates due to impurities introduced upon contact with the liquid crystal panel 1. Therefore, even when the liquid crystal 14 filled in the container 12 is injected into the plurality of liquid crystal panels 1, the liquid crystal 14 remaining after the injection must be discarded. This leads to an increase in manufacturing cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object thereof is to provide a liquid crystal dropping device and a liquid crystal dropping method for directly dropping a liquid crystal onto a large glass substrate including at least one liquid crystal panel.

Another object of the present invention is to provide a liquid crystal dropping device and a liquid crystal dropping method capable of accurately measuring the amount of liquid crystal dropped on a substrate in real time.

It is still another object of the present invention to provide a liquid crystal dropping apparatus and a liquid crystal dropping method capable of always dropping an accurate amount of liquid crystal onto a substrate.

In order to achieve the above object, the liquid crystal dropping apparatus according to the present invention is to drop the container filled with the liquid crystal, the discharge pump for sucking and discharging the liquid crystal filled in the container, and the liquid crystal discharged from the discharge pump to the substrate It consists of a nozzle and the flowmeter which measures the flow volume of the liquid crystal which flows out from the said container, and detects the dripping amount of the liquid crystal dropped on a board | substrate.

The discharge pump is inserted into the cylinder, the cylinder, a groove is formed in a predetermined lower portion of the piston to suck and discharge the liquid crystal as the rotation and up and down movement, and the liquid crystal is sucked and discharged as the piston moves It is composed of a suction port and a discharge port, the discharge pump further comprises a fixing part including a rotating member fixed to the piston to rotate the piston. In addition, a bar is formed in the piston and a hole is formed in the rotating member so that the bar is rotatably inserted into the hole so that the piston is fixed to the rotating member. The liquid crystal volume of the discharge pump varies depending on the angle at which the piston is fixed to the rotating member.

The flow meter is installed in a first connecting tube disposed between the liquid crystal container and the discharge pump, and heating means for heating the first connecting tube, and installed at two points of the first connecting tube, It consists of a 1st temperature sensor and a 2nd temperature sensor which measure the temperature difference of the two loads of a connection pipe. In this case, the heating means, the first temperature sensor and the second temperature sensor may be installed in the second connecting pipe provided between the discharge pump and the nozzle.

The flow rate of the liquid crystal measured by the flowmeter is input to the control unit, wherein the control unit detects the difference between the temperatures measured by the first temperature sensor and the second temperature sensor, and the liquid crystal based on the temperature difference detected by the temperature difference detection unit. The dripping detection unit detects the actual dripping amount of the load, and the dripping correction unit corrects the dripping amount of the liquid crystal by the difference when a difference occurs by comparing the set dripping amount and the actual dripping amount detected by the dripping amount detecting unit.

In addition, the liquid crystal dropping apparatus according to the present invention includes the steps of loading a substrate on which a plurality of liquid crystal panels are formed, setting a dropping amount of the liquid crystal, dropping the liquid crystal onto the substrate by operating a liquid crystal discharge pump, Measuring the temperature of the flow path to detect the actual amount of the liquid crystal and the step of correcting the amount of drop by comparing the set amount of drop and the actual drop.

In order to overcome the shortcomings of the conventional liquid crystal injection method such as the liquid crystal dipping method or the liquid crystal vacuum injection method, a method proposed in recent years is a liquid crystal layer forming method by the liquid crystal dropping method. The liquid crystal dropping method does not inject the liquid crystal by the pressure difference between the inside and the outside of the panel, but directly drops and dispenses the liquid crystal onto the substrate, and uniformly spreads the liquid crystal dropped by the bonding pressure of the panel. The liquid crystal layer is formed by distribution. Since the liquid crystal dropping method directly drops the liquid crystal onto the substrate for a short time, the liquid crystal layer formation of the large area liquid crystal display device can be performed very quickly, and only the required amount of liquid crystal is directly dropped onto the substrate. Since it is possible to minimize the consumption of the liquid crystal display device has the advantage that can significantly reduce the manufacturing cost.

4 is a view showing a basic concept of the liquid crystal dropping method. As shown in the figure, in the liquid crystal dropping method, before the lower substrate 105 and the upper substrate 103 on which the driving element and the color filter are formed, respectively, the liquid crystal 107 is droplet-shaped on the lower substrate 105. Dropping The liquid crystal 107 may be dropped on the substrate 103 on which the color filter is formed. In other words, the substrate to be the liquid crystal dropping method in the liquid crystal dropping method can be either a TFT substrate or a CF substrate. However, when the substrates are bonded, the substrate on which the liquid crystal is dropped must be placed at the bottom.

In this case, a sealing material 109 is applied to the outer region of the upper substrate 103 to apply pressure to the upper substrate 103 and the lower substrate 105 so that the upper substrate 103 and the lower substrate 105 are bonded together. At the same time, droplets of the liquid crystal 107 are spread out by the pressure to form a liquid crystal layer having a uniform thickness between the upper substrate 103 and the lower substrate 105. In other words, the biggest feature of the liquid crystal dropping method is that the liquid crystal 107 is previously dropped on the lower substrate before the panel 101 is bonded, and then the panel is bonded by the sealing material 109.

The liquid crystal display device manufacturing method to which the above liquid crystal dropping method is applied is shown in FIG. 5. As shown in the figure, TFT and color filter layers, which are driving elements, are formed on the lower substrate 150 and the upper substrate 103 through the TFT array process and the color filter process (S201 and S202). The TFT array process and the color filter process are the same as those of the conventional manufacturing method shown in FIG. 2 and are collectively performed on a large-area glass substrate on which a plurality of panel regions are formed. In particular, since the liquid crystal dropping method is applied in the manufacturing method, it can be usefully used in a larger glass substrate, for example, a large area glass substrate having an area of 1000 × 1200 mm ² or more compared with the conventional manufacturing method.

Subsequently, after the alignment film is applied to the lower substrate 105 on which the TFT is formed and the upper substrate 103 on which the color filter layer is formed, rubbing is performed (S202 and S205), the liquid crystal panel region of the lower substrate 105 is formed. 107 is dropped and a sealing material 109 is applied to the liquid crystal panel outer region of the upper substrate (S203, S206).

Thereafter, pressure is applied while the upper substrate 103 and the lower substrate 105 are aligned, and the upper substrate 105 and the lower substrate 103 are bonded together by a sealing material 109 and at the same time the application of pressure is applied. The liquid crystal 107 dropped by this is spread evenly over the whole panel (S207). Through this process, a plurality of liquid crystal panels having a liquid crystal layer are formed on glass substrates (lower substrates and upper substrates) having a large area. The glass substrates are processed and cut and separated into a plurality of liquid crystal panels. By inspecting, a liquid crystal display device is produced (S208, S209).

Comparing the difference between the method of manufacturing the liquid crystal display device to which the liquid crystal drop method shown in FIG. 5 is applied and the method of manufacturing the liquid crystal display device to which the conventional liquid crystal injection method shown in FIG. 2 is applied, the difference between the vacuum injection and the liquid crystal drop of the liquid crystal and In addition to the difference in the processing time of the large-area glass substrate it can be seen that there are other differences. That is, in the method of manufacturing a liquid crystal display device to which the liquid crystal injection method shown in FIG. 2 is applied, the injection hole must be sealed by an encapsulant after the liquid crystal is injected through the injection hole. This eliminates the need for sealing of these inlets. In addition, although not shown in FIG. 2, in the manufacturing method to which the liquid crystal injection method is applied, since the substrate contacts the liquid crystal when the liquid crystal is injected, the outer surface of the panel is contaminated by the liquid crystal. In the manufacturing method in which the liquid crystal dropping method is applied, since the liquid crystal is directly dropped on the substrate, the panel is not contaminated by the liquid crystal, and as a result, the cleaning process is unnecessary. As described above, the manufacturing method of the liquid crystal display device by the liquid crystal dropping method is a simple process by the manufacturing method by the liquid crystal injection method, so that not only the manufacturing efficiency can be improved but also the yield can be improved.

In the manufacturing method of the liquid crystal display device in which the liquid crystal dropping method is introduced as described above, the most important factors for accurately forming the liquid crystal layer to a desired thickness are the position of the liquid crystal to be dropped and the amount of liquid crystal dropping. In particular, since the thickness of the liquid crystal layer has a close relationship with the cell gap of the liquid crystal panel, the accurate dropping position and the dropping amount of the liquid crystal are very important factors for preventing defects of the liquid crystal panel. Therefore, there is a need for an apparatus for dropping the correct amount of liquid crystal at the correct position, and the present invention provides such liquid crystal droplets.

6 is a view showing a basic concept of dropping the liquid crystal 107 on the substrate (large area glass substrate) 105 using the liquid crystal drop according to the present invention. As shown in the figure, the liquid crystal droplets 120 are provided on the substrate 105. Although not shown in the figure, the liquid crystal is filled in the liquid crystal dropper 120 to fill a predetermined amount on the substrate.

Typically, the liquid crystal is dropped onto the substrate in the form of droplets. Since the substrate 105 moves at a set speed in the x and y directions, and liquid crystals discharge liquid crystals at set time intervals, the liquid crystals 107 dropped on the substrate 105 are spaced at regular intervals in the x and y directions. Is placed. Of course, the liquid crystal dropping substrate 105 may be fixed and the liquid crystal dropping 120 may move in the x and y directions to drop the liquid crystal at a predetermined interval. However, in this case, since the droplet-shaped liquid crystals are shaken by the movement of the liquid crystal dropping 120, an error may occur in the dropping position and the dropping amount of the liquid crystal. Therefore, the liquid crystal dropping 120 is fixed and the substrate 105 is moved. It is desirable to.

FIG. 7 is a perspective view showing the structure of the liquid crystal dropper 120 according to the present invention, and FIG. 8 is a perspective exploded view of the liquid crystal dropper 120. As illustrated in FIGS. 7 and 8, in the liquid crystal dropper 120, a cylindrical liquid crystal container 122 is accommodated in the case 123. The liquid crystal container 122 is made of polyethylene, and the liquid crystal 107 is filled therein, and the case 123 is made of stainless steel so that the liquid crystal container 122 is formed therein. It is stored. In general, polyethylene is mainly used as the liquid crystal container 122 because it is easy to form a container having a desired shape because of its excellent moldability and does not react with the liquid crystal when the liquid crystal 107 is filled. However, since the polyethylene is weak in strength, the polyethylene is easily deformed by a weak external shock. In particular, when polyethylene is used as the liquid crystal container 122, the container 122 may be deformed to drop the liquid crystal 107 in the correct position. Since it is not present, it is stored in a case 123 made of stainless steel with high strength, and used.

On the other hand, although not shown in the figure, a gas supply pipe is connected to the upper portion of the liquid crystal container 122 is supplied with a gas such as nitrogen from the outside. This gas supply prevents the pressure drop in the region where the liquid crystal is not filled in the liquid crystal container 122 when the liquid crystal is dropped, thereby preventing the liquid crystal dropping.

The liquid crystal container 122 may be formed of a metal such as stainless steel. In this case, since the liquid crystal container 122 is not deformed by an external impact, the outer case 123 is not necessary. Therefore, the manufacturing cost of the liquid crystal dropper 120 can be reduced. As such, when the liquid crystal container 122 is formed of a metal, it is preferable to apply a fluorine resin film therein to prevent the filled liquid crystal 107 from causing a chemical reaction with the metal.

The liquid crystal discharge pump 140 is disposed below the liquid crystal container 122. The liquid crystal discharge pump 140 discharges a predetermined amount of liquid crystal of the liquid crystal container 122 and drops the liquid on the substrate. The liquid crystal is discharged as the liquid crystal discharge pump 140 is connected to the liquid crystal container 122. The liquid crystal suction opening 147 and the liquid crystal suction opening 147 are formed opposite to each other, and the liquid crystal discharge pump 140 operates to discharge the liquid crystal.

As shown in FIG. 8, the first connection pipe 126 is coupled to the liquid crystal suction opening 147. Although the liquid crystal suction opening 147 is inserted and coupled to the first connection pipe 126 in the drawing, the liquid crystal suction opening 147 and the first connection pipe 126 may be coupled by a coupling means such as a screw. One side of the first connection tube 126 is formed with a pin 128 through which the inside is perforated, such as a needle, and the lower portion of the liquid crystal container 122 that outflows the liquid crystal into the first connection tube 126. And pads (not shown) made of a material having strong shrinkage and sealing properties such as butyl rubber series. The pin 128 is inserted into the liquid crystal container 122 through a pad and flows the liquid crystal 107 of the liquid crystal container 122 into the liquid crystal suction opening 147. Since the pad is strongly contracted into the pin 128 when the pin 128 is inserted, the liquid crystal 107 may be prevented from leaking into the insertion region of the pin 128. As such, since the liquid crystal suction opening 147 and the liquid crystal container 122 are fastened by the pins and the pads, the fastening structure is simplified, and as a result, the fastening and detaching can be easily performed.

The liquid crystal suction opening 147 and the first connection pipe 126 may be integrally formed. In this case, the pin 128 is formed in the liquid crystal suction opening 147 and inserted directly into the liquid crystal container 122 through a pad to leak the liquid crystal of the liquid crystal container 122, thereby simplifying the structure.

In addition, a flow meter 190 is installed in the first connecting pipe 126. The flow meter 190 is for measuring the outflow amount of the liquid crystal flowing out of the liquid crystal container 122, and by measuring the outflow amount of the liquid crystal from the liquid crystal container 122 can detect the drop amount of the liquid crystal dropped in the liquid crystal dropping Will be. As shown in FIG. 9, the flow meter 190 is installed in the first connection pipe 192 and the upper and lower portions of the heater 192 and the first connection pipe 192 to heat the first connection pipe 192. That is, the first temperature sensor 194 and the second temperature sensor 194 are respectively provided upstream and downstream of the liquid crystal from the liquid crystal container 122. The first connection pipe 192 heated by the heater 192 and the temperature is increased, the temperature is lowered by the heat transfer to the liquid crystal as the liquid crystal flows. In particular, as the liquid crystal flows, the temperature decreases from the upstream to the downstream side by heat transfer. The dropping amount of the liquid crystal flowing through the first connector tube 126 is measured based on the temperature drop of the first connector tube 192 according to the flow of the liquid crystal.

As shown in FIG. 9, the temperature measured by the first temperature sensor 194 and the second temperature sensor 194 is input to the controller 200, and the controller 200 flows the liquid crystal based on the input temperature. Detects the amount of the liquid crystal dropping by detecting and compares the detected dropping amount with the set amount and then corrects the dropping amount so that the correct amount of liquid crystal is always dropped on the substrate.

The nozzle 150 is installed below the liquid crystal discharge pump 140. The nozzle 150 is connected to the liquid crystal discharge port 148 of the liquid crystal discharge pump 140 through the second connection pipe 160 to drop the liquid crystal 107 discharged from the liquid crystal discharge pump 150 on a substrate. .

The second connection pipe 160 may be formed of an opaque material, but may be formed of a transparent material. As described above, the reason for forming the second connection tube 160 made of a transparent material is as follows.

Generally, bubbles are contained in the liquid crystal 107 when the liquid crystal is dropped, and the drop amount of the liquid crystal 107 dropped on the substrate cannot be accurately controlled. Therefore, bubbles must be removed when the liquid crystal 107 is dropped. Meanwhile, bubbles are already included in the liquid crystal 107 filled in the liquid crystal container 122. Although bubbles in the liquid crystal 107 can be removed by the bubble removing device, it is virtually impossible to remove all bubbles even in this case. In addition, bubbles may occur when the liquid crystal 107 is introduced into the liquid crystal discharge pump 140 from the liquid crystal container 122. As a result, it is almost impossible to completely remove bubbles from the dropped liquid crystal 107. Therefore, when bubbles are generated, removing bubbles by discontinuing the operation of the liquid crystal droplets may be the best way to prevent defects.

The second connecting tube 160 is formed of a transparent material to easily detect bubbles included in the liquid crystal container 122 or bubbles generated in the liquid crystal container 122 to prevent defects. At this time, the discovery of the bubble may be made by the operator's naked eye, but the first sensor 162 such as a photo coupler on both sides of the second connecting tube 160 to automatically detect the bubble. It will be possible to more reliably prevent defects.

On both sides of the nozzle 150 into which the liquid crystal discharged through the second connecting pipe 160 flows, protection parts 152 are installed to prevent the nozzle 150 from being damaged from an external force. The protection part 152 of the lower part of the 150 is provided with a second sensor 154 for detecting whether the liquid crystal dropped from the nozzle 150 contains bubbles or agglomerates of liquid crystal on the surface of the nozzle 150. .

The phenomenon that the liquid crystal agglomerates on the surface of the nozzle 150 prevents the accurate dropping of the liquid crystal 107. When the liquid crystal is dropped through the nozzle 150, even if a predetermined amount of liquid crystal is discharged from the liquid crystal discharge pump 140, some of the liquid crystal is spread onto the surface of the nozzle 150, so that less liquid crystal is dropped on the substrate. In addition, when the liquid crystals agglomerated on the surface of the nozzle 150 are dropped onto the substrate, it may cause a fatal defect of the liquid crystal display device. As such, in order to prevent the liquid crystals from agglomerating on the surface of the nozzle 150, a material (ie, a hydrophobic material) having a high contact angle with respect to the liquid crystal, such as a fluorine resin, is dipping on the surface of the nozzle 150. Or by a spray method. The liquid crystal dropped by the application of the fluorine resin is dropped onto the substrate through the nozzle 150 in the form of a perfect drop without spreading to the surface of the nozzle 150.

On the other hand, the liquid crystal discharge pump 140 is inserted into the rotating member 157, the rotating member 157 is fixed to the fixing portion 155. The rotating member 157 is connected to the first motor 131. As the first motor 131 operates, the rotating member 157 rotates, and the liquid crystal discharge pump 140 fixed to the rotating member 157 operates.

The liquid crystal discharge pump 140 is in contact with one side of the liquid crystal volume adjusting member 134 having a shape such as a bar. The other side of the liquid crystal volume adjustment member 134 is formed with a hole, the rotating shaft 136 is inserted into the hole. A screw is formed around the hole of the liquid crystal volume adjusting member 134 and the rotating shaft 136, and is screwed together. In addition, one end of the rotating shaft 136 is connected to the second motor 133, the other end is connected to the control lever 137.

The amount of liquid crystal discharged from the liquid crystal container 122 through the liquid crystal discharge pump 140 depends on the angle fixed to the rotating member 157. That is, the liquid crystal volume of the liquid crystal discharge pump 140 varies according to the fixed angle fixed to the rotating member 157. When the second motor 133 connected to the rotary shaft 136 is driven (automatically adjusted) or the control lever 137 is operated (manually adjusted), the rotary shaft 136 is rotated, thus rotating screw 136 and the screw One end of the combined liquid crystal volume adjustment member 134 is moved back and forth (straight line) along the rotation axis 136. As such, the force applied to the liquid crystal discharge pump 140 is changed as one end of the liquid crystal volume adjusting member 134 moves, and as a result, the fixed angle of the liquid crystal discharge pump 140 is changed.

As described above, the first motor 131 operates the liquid crystal discharge pump 140 to discharge the liquid crystal of the liquid crystal container 122 to drop the liquid onto the substrate, and the second motor 133 is fixed to the rotating member 157. The fixed angle of the liquid crystal discharge pump 140 is controlled to control the amount of liquid crystal discharged from the liquid crystal discharge pump 140.

Meanwhile, the one-time dropping amount of the liquid crystal dropped onto the substrate through the liquid crystal discharge pump 140 is a very small amount, and thus the amount of change of the liquid crystal discharge pump 140 controlled by the second motor 133 is also a small amount. . This means that the inclination angle of the liquid crystal discharge pump 140 must be adjusted very finely in order to control the discharge amount of the liquid crystal discharge pump 140. For such fine adjustment, the second motor 133 uses a step motor operated by a pulse input value.

10A and 10B are views showing the structure of the liquid crystal discharge pump 140. FIG. 10A is a perspective view and FIG. 10B is an exploded perspective view.

10A and 10B, the liquid crystal discharge pump 140 has a case 141 in which a liquid crystal suction opening 147 and a liquid crystal discharge opening 148 are formed, and an opening is formed at an upper portion thereof, and is coupled to the case 141. The cap 144 is inserted into the case 141, the cylinder 142 is sucked into the liquid crystal, the sealing means 143 for sealing the cylinder 142, and is located above the cap 144 O-ring (144a) for preventing the leakage of the liquid crystal and the liquid crystal suction opening 147 and the liquid crystal discharge port 148 by being inserted into the cylinder 142 through the opening of the cap 144 to move up and down It consists of a piston 145 for sucking and discharging the liquid crystal 107 through. A head 146a fixed to the rotating member 157 is provided at an upper portion of the piston 145, and a bar 146b is installed at the head 146a. The bar 146b is inserted into and fixed to a hole (not shown) formed in the rotating member 157 so that the piston 145 rotates when the rotating member 157 is rotated by the force of the first motor 131. ) To rotate.

On the other hand, as shown in Figure 10b, the groove 145a is formed at the end of the piston 145. The groove 145a is formed in an area of about 1/4 (or less) in the circular cross section of the piston 145 so that the piston 145 rotates (ie, moves up and down) and the liquid crystal suction opening 147. And opening and closing the liquid crystal discharge opening 148 to suck and discharge the liquid crystal through the liquid crystal suction opening 147 and the liquid crystal discharge opening 148.

Referring to the operation of the liquid crystal discharge pump 140 in detail as follows.

11 is a view showing a state in which the liquid crystal discharge pump 140 is fixed to the rotating member 157. As shown in the figure, the piston 145 is fixed to the rotating member 157 at an angle α, and the bar 146b formed on the piston head 146a is a hole formed in the inner surface of the rotating member 157. The piston 145 and the rotary member 157 are inserted into the 159. Although not shown in the drawing, since the bearing is provided inside the hole 159, the bar 146b of the piston 145 inserted into the hole 159 can move back, forth, left, and right. When the first pump 131 operates, the rotating member 157 rotates, and as a result, the piston 145 coupled with the rotating member 157 (that is, fixed) rotates.

At this time, assuming that the fixed angle α of the liquid crystal discharge pump with respect to the rotating member 157, that is, the fixed angle α of the piston 145 with respect to the rotating member 157 is 0, the piston 145 rotates only. Only rotational movement is performed along the member 157. However, since the fixed angle α is not substantially zero (that is, fixed at a constant angle), the piston 145 rotates along the rotational movement of the rotating member 157 and simultaneously moves up and down. Will be.

During the movement of the piston 145, when the piston 145 is rotated by an angle to move upwards, an empty space is created inside the cylinder 142, the liquid crystal is sucked into the space through the liquid crystal suction opening 147, Thereafter, as the piston 145 further rotates, the piston 145 moves downward, and the liquid crystal sucked in the cylinder 142 is discharged through the liquid crystal discharge port 148. At this time, the groove 145a formed in the piston 145 serves to open and close the liquid crystal suction opening 147 and the liquid crystal discharge opening 148 during the suction and discharge of the liquid crystal by the rotation of the piston 145.

Hereinafter, the operation of the liquid crystal discharge pump 140 as described above will be described in more detail with reference to FIGS. 12A to 12D.

12A to 12D, the liquid crystal discharge pump 140 discharges the liquid crystal 107 of the liquid crystal container 122 to the nozzle 150 through four strokes. 12A and 12C are cross strokes. 12B is a suction stroke through the liquid crystal suction port 147 and FIG. 12D is a liquid crystal discharge stroke through the liquid crystal discharge port 148.

As shown in FIG. 12A, the piston 145 fixed to the rotating member 157 at an angle α rotates as the rotating member 157 rotates. At this time, the liquid crystal suction opening 147 and the liquid crystal discharge opening 148 are closed by the piston 145.

As the rotating member 157 rotates about 45 °, the piston 145 also rotates, so that the liquid crystal suction opening 147 is opened by the groove 145a of the piston 145 as shown in FIG. 12B. Meanwhile, the bar 146b of the piston 145 is inserted into the hole 159 of the rotating member 157 to couple the rotating member 157 and the piston 145. Therefore, the piston 145 is rotated as the rotating member 157 rotates, wherein the bar 146b is rotated along the rotation surface.

Since the piston 145 is fixed to the rotating member 157 at an angle and the bar 146b rotates along the rotating surface, the piston 145 is raised as the rotating member 145 rotates. In addition, since the cylinder 142 is fixed, as the rotating member 145 rotates, a space is created in the cylinder 142 below the piston 145. Therefore, the liquid crystal is sucked into the space through the liquid crystal suction opening 147 opened by the groove 145a.

The suction of the liquid crystal is carried out until the suction stroke starts (that is, after the liquid crystal suction opening 147 is opened), and the rotating member 157 rotates about 45 ° to start the suction stroke as shown in FIG. 12C (liquid crystal suction opening). Until 147 is closed).

Thereafter, as shown in FIG. 12D, as the rotary member 157 is further rotated, the liquid crystal discharge port 148 is opened and the piston 145 starts to descend, and is sucked into the space in the cylinder 142. Liquid crystal is discharged through the liquid crystal discharge port 148 (discharge stroke).

As described above, the liquid crystal discharge pump 140 repeats four strokes consisting of a first cross stroke, a suction stroke, a second cross stroke, and a discharge stroke, thereby discharging the liquid crystal 107 filled in the liquid crystal container 122 through the nozzle 150. To be discharged.

At this time, the discharge amount of the liquid crystal depends on the vertical movement range of the piston 145. However, the vertical movement range of the piston 145 varies depending on the angle of the liquid crystal discharge pump 140 fixed to the rotating member 157.

13 is a view showing that the liquid crystal discharge pump 140 is fixed to the rotating member 157 at the angle of β. Compared to FIG. 11, in which the liquid crystal discharge pump 140 is fixed to the rotating member 157 at an angle of α (<β), the liquid crystal discharge pump 140 of FIG. 13 allows the piston 145 to move higher in the upward direction. do. This means that as the angle fixed to the rotating member 157 increases, the amount of the liquid crystal 107 sucked into the cylinder 142 during the movement of the piston 145 increases, which is fixed to the rotating member 157. It means that the discharge amount of the liquid crystal can be controlled by adjusting the angle.

Meanwhile, as shown in FIG. 7, the angle of the liquid crystal discharge pump 140 fixed to the rotating member 157 is controlled by the liquid crystal volume adjusting member 134, and the liquid crystal volume adjusting member 134 is provided as a second. As the pump 133 is driven, it moves. In other words, the angle of the liquid crystal discharge pump 140 can be adjusted by controlling the second pump 133.

Of course, the operator may manually adjust the fixed angle of the liquid crystal discharge pump 140 by the angle adjusting lever 137, but in this case, accurate adjustment is not possible and time consuming and stops the liquid crystal discharge pump during the operation. There is also a disadvantage. Therefore, it is preferable that the fixed angle of the liquid crystal discharge pump 140 is adjusted by the second pump 133.

On the other hand, when the liquid crystal is dropped onto the substrate using the liquid crystal drop configured as described above, it is necessary to check whether the drop amount of the liquid crystal actually dropped onto the substrate matches the set drop amount. If the actual amount of liquid crystal dropping is smaller than the set optimal dropping amount, for example, a liquid crystal display device in a normally black mode will cause a problem in black brightness and normally a white mode. In the case of the liquid crystal display device of), a problem occurs in white luminance.

In addition, when the amount of liquid crystal actually dropped is more than the optimum amount of dropping, gravity failure occurs when the liquid crystal panel is manufactured. Gravity defect occurs when the liquid crystal layer formed inside the liquid crystal panel increases in volume due to temperature increase when the liquid crystal panel is manufactured. The cell gap of the liquid crystal panel becomes larger than the spacers, and thus the liquid crystal is moved downward by gravity. Since the cell gap of the liquid crystal panel is uneven due to the movement, the quality of the liquid crystal display device is reduced.

In order to prevent such a defect, the actual amount of dripping on the substrate by liquid crystal dropping is measured, compared with the set dripping amount, and the actual dripping amount must be corrected by the difference value.

The dripping amount of liquid crystal can be measured by various methods. The easiest method is to have a separate container and drop a predetermined number of liquid crystals from the liquid crystal dropping, and then measure the weight of the dropped liquid crystals and convert them into volume to measure the amount of liquid crystal dropping. However, in this method, since the liquid crystal dropping on the substrate must be used for the measurement of the dropping amount, there is a problem that the process is delayed. Moreover, the loading amount for the loading measurement and the loading on the actual substrate may vary depending on external conditions, making it very difficult to precisely measure the loading amount of the minute amount.

However, in the present invention, as shown in FIGS. 8 and 9, the liquid crystal dropped onto the substrate by measuring the flow rate of the liquid crystal flowing out of the liquid crystal container 122 by the flow meter 190 installed in the first connection pipe 126. The load can be measured. Outflow of the liquid crystal from the liquid crystal container 122 occurs only when the liquid crystal discharge pump 140 is operated, and the amount thereof is equal to the amount sucked by the liquid crystal discharge pump 140. On the other hand, since the amount discharged by the liquid crystal discharge pump 140 is the same as the suction amount, the liquid crystal finally dropped on the substrate by one stroke of the liquid crystal discharge pump 140 is the same as the flow rate measured by the flow meter 190 Therefore, the drop amount of the liquid crystal can be measured.

As shown in FIG. 9, the temperature of the first connection pipe 126 measured by the first temperature sensor 194 and the second temperature sensor 196 of the flow meter 190 is input to the controller 200 to control the liquid crystal. Measure the load. 14 is a block diagram showing the structure of the controller 200. As shown in FIG. 14, the temperature of the first connecting pipe 126 measured by the first temperature sensor 194 and the second temperature sensor 196 is input to the temperature difference detector 204 to flow upstream and downstream of the liquid crystal. The temperature difference is detected, and the detected temperature difference value is transmitted to the dripping amount detection unit 206. The drop amount detection unit 206 flows out the drop amount of the liquid crystal dropped on the substrate based on the input temperature difference value (strictly, it flows from the liquid crystal container 122 to the liquid crystal discharge pump 140 by one stroke of the liquid crystal discharge pump). Amount) is detected.

Substantially measuring the flow rate of the liquid crystal is not due to temperature but due to the amount of heat transferred from the heated first connector tube 126 to the liquid crystal according to the flow of the liquid crystal. However, the difference value between the temperature upstream and downstream of the first connector tube 126 through which the liquid crystal flows means the difference in the amount of heat transferred from the first connector tube 126 to the liquid crystal while flowing from the upstream to the downstream, The flow rate of the liquid crystal can be measured.

Substantially, the dripping amount calculation unit 206 is set with dripping data of the liquid crystal with respect to the temperature difference. Therefore, when the temperature difference value is input from the temperature difference detection unit 204, it is possible to detect the drop amount of the liquid crystal currently being dropped in real time.

On the other hand, the drop amount setting unit 202 sets the drop amount of the liquid crystal dropped on the liquid crystal panel. Although the setting of the dripping amount may be input manually by the operator, it is preferable to set the optimal dripping amount automatically based on various data for the more accurate dripping amount setting. At this time, the setting of the drop amount is made based on various data such as the size of the liquid crystal panel to be manufactured, the number of liquid crystal panels included in the substrate, the cell gap (ie, the height of the spacer) of the liquid crystal panel, and the information on the liquid crystal.

The drop amount of the liquid crystal set by the drop amount setting unit 202 and the current drop amount detected by the drop amount detection unit 206 are input to the drop amount correction unit 208. The setting value of the dripping amount inputted from the dripping amount adjusting unit 208 is compared with a detected value (measured value), and when a difference occurs, the signal is output to the driving unit 210. The driving unit 210 adjusts the discharge amount of the liquid crystal by driving the second motor 133 and adjusting the angle fixed to the rotating member 157 according to a signal input from the dropping amount correction unit 208.

On the other hand, the output unit 212 is composed of a display and a printer, such as a CRT (Cathod Ray Tube) or LCD, the operator can load a variety of information about the load, such as the setting load, the load detected at the current load, the difference between the set amount and the detection amount In addition to providing to the operator, if a difference occurs between the set amount and the detected amount by the alarm (alarm), etc. to inform the operator of the loading abnormality.

As described above, in the present invention, by measuring the flow rate of the liquid crystal flowing out of the liquid crystal container 122 using the flow meter 190 accurately detects the amount of the liquid crystal dropped on the substrate, based on the detected amount By correcting the drop amount of the liquid crystal, the correct amount of liquid crystal is always dropped on the substrate.

In particular, in the present invention, the flow rate of the liquid crystal is measured by using the difference in calories of the first connection pipe 126 through which the liquid crystal flows. By using such a flow meter, the following advantages can be obtained.

First, it is possible to measure the drop amount of the fine liquid crystal. The dropping amount of the liquid crystal dropped on the substrate (that is, the discharge amount of the liquid crystal by one stroke of the liquid crystal discharge pump 140) is a very small amount of several mg. Therefore, a precise flow rate cannot be measured by a flow meter for measuring the volume of the fluid, whereas the flow meter used in the present invention uses the difference in calories at two points of the first connection pipe 126 due to the liquid crystal. The dripping amount of can be measured accurately.

Second, it is not affected by external influences. Since the flow meter of the present invention measures the amount of dropping by the difference in relative calories between two points of the first connection pipe 126, it is possible to always accurately measure the amount of dropping without being influenced by external conditions such as external temperature or pressure. do.

Third, the structure is simple and the installation cost is low. The flowmeter applied to the present invention requires only a heater and a temperature sensor, and does not need a correction means for removing the influence of other mechanical devices or external conditions, so that the structure is simpler and cheaper to install than other flowmeters. .

Hereinafter, a liquid crystal dropping method using the liquid crystal dropping apparatus having the above structure will be described in detail with reference to the accompanying drawings.

Fig. 17 is a view showing a method of dropping liquid crystal onto a substrate on which a plurality of liquid crystal panels are formed using a liquid crystal dropping device having a flow meter.

As shown in the figure, when the operator inputs the size of the liquid crystal panel, the cell gap and the characteristic information of the liquid crystal by operating a keyboard, a mouse, a touch panel, or the like, the drop amount setting unit 202 drops the amount of liquid crystal to be dropped onto the substrate. 301 is set. Subsequently, the liquid crystal dropping is driven to start dropping the liquid crystal on the substrate (S302).

As the liquid crystal is dropped on the substrate as described above, the flow meter 190 installed in the first connecting pipe 126 measures the temperature at two points (upstream and downstream) through which the liquid crystal flows, and based on the temperature, the drop detection unit ( In step 206, the dropping amount of the liquid crystal currently being loaded is detected in real time (S303 and S304).

In the dripping amount correction unit 208, the set dripping amount is compared with the detected actual dripping amount (S305). If a difference occurs, the difference value is calculated, and then the second motor 133 is driven to make the liquid crystal corresponding to the difference value. The amount of dripping is corrected (S306, S307).

As described above, in the present invention, the flow rate meter for measuring the flow rate of the liquid crystal is provided in the first connecting pipe 126 below the liquid crystal drop so that the drop amount of the liquid crystal dropped on the substrate can be accurately measured. On the other hand, in the above description, the flow meter 190 is installed in the first connecting pipe 126 to measure the flow rate of the liquid crystal flowing out of the liquid crystal container 122 by the operation of the liquid crystal discharge pump 140 to reduce the amount of liquid crystal dropping. However, the flow meter 190 applied to the present invention is not installed only in the first connection pipe 126.

Since the purpose of the flow meter 190 is to detect the dripping amount of the liquid crystal by measuring the flow rate, it may be installed at all possible positions. For example, a flowmeter may be installed in the second connection pipe 160 to directly measure the flow rate of the liquid crystal discharged from the liquid crystal discharge pump 140.

On the other hand, the above description relates to a preferred embodiment of the present invention, it does not limit the scope of the present invention. The concept of the present invention is to always drop an accurate liquid crystal onto a substrate by providing a flow meter to detect the amount of liquid crystal dropping. Thus, the present invention is not limited to the liquid crystal phase of the specific structure disclosed in the above description, but may be applied to the liquid crystal phase of various structures.

As described above, in the present invention, by installing a flow meter for measuring the flow rate of the liquid crystal in the flow path of the liquid crystal, it is possible to accurately detect the amount of liquid crystal dropping in real time, and correct the actual drop amount of the liquid crystal based on the detected drop amount As a result, the correct amount of liquid crystal can always be loaded onto the substrate.

Claims (21)

A container filled with liquid crystal; A discharge pump for sucking and discharging the liquid crystal filled in the container; A nozzle for dropping the liquid crystal discharged from the discharge pump onto a substrate; And And a flow meter for measuring a flow rate of the liquid crystal flowing out of the container and detecting a drop amount of the liquid crystal dropped on the substrate. The method of claim 1, wherein the discharge pump, cylinder; A piston which is inserted into the cylinder and has a groove formed in a predetermined region of the lower portion to suck and discharge the liquid crystal as the rotary and vertical movements occur; And a suction port and a discharge port through which the liquid crystal is sucked and discharged as the piston moves. The liquid crystal dropping device of claim 2, further comprising a fixing part to which the discharge pump is fixed. The liquid crystal dropping apparatus of claim 3, wherein the fixing unit includes a rotating member to which the piston of the discharge pump is fixed to rotate the piston. The liquid crystal dropping apparatus according to claim 4, wherein a bar is formed in the piston, and a hole is formed in the rotating member, and the bar is rotatably inserted into the hole so that the piston is fixed to the rotating member. The liquid crystal dropping apparatus according to claim 4, wherein the liquid crystal volume of the discharge pump varies depending on an angle at which the piston is fixed to the rotating member. The liquid crystal dropping apparatus according to claim 1, further comprising a liquid crystal volume adjusting member for contacting the discharge pump to change a fixed angle of the discharge pump to adjust the discharge amount of the liquid crystal. The method of claim 7, wherein A motor for driving the liquid crystal volume adjusting member; And And a rotating shaft which is screwed with the liquid crystal volume adjusting member and rotates as the motor is driven to linearly move the liquid crystal volume adjusting member. The liquid crystal dropping apparatus according to claim 1, further comprising a first connection pipe installed between the container and the discharge pump to introduce liquid crystal of the container into the discharge pump. The flow meter of claim 9, wherein Heating means installed in the first connecting pipe to heat the first connecting pipe; And And a first temperature sensor and a second temperature sensor installed at two points of the first connector and measuring a temperature difference between two points of the first connector by heat transfer with the liquid crystal. The liquid crystal dropping apparatus according to claim 1, further comprising a second connecting tube positioned between the discharge pump and the nozzle to guide the liquid crystal discharged from the discharge pump to the nozzle. The method of claim 11, wherein the flow meter, Heating means installed in the second connecting pipe to heat the second connecting pipe; And And a first temperature sensor and a second temperature sensor installed at two points of the second connector and measuring a temperature difference between two points of the second connector by heat transfer with the liquid crystal. The liquid crystal dropping apparatus according to claim 1, further comprising a control unit for controlling a dropping amount of the liquid crystal based on the flow rate of the liquid crystal input from the flow meter. The method of claim 13, wherein the control unit, A temperature difference detector for detecting a difference between temperatures measured by the first temperature sensor and the second temperature sensor; A drop amount detection unit that detects an actual drop amount of the liquid crystal based on the temperature difference detected by the temperature difference detection unit; And A liquid crystal dropping device comprising: a drop loading correction unit for comparing a set dropping amount with a real dropping amount detected by the dropping amount detecting unit and correcting the dropping amount of the liquid crystal by the difference when a difference occurs. 15. The liquid crystal dropping apparatus according to claim 14, further comprising an output unit for displaying a liquid crystal drop setting amount, a current liquid crystal drop amount, and a correction value to notify an operator. Loading a substrate on which a plurality of liquid crystal panels are formed; Setting a dropping amount of the liquid crystal; Operating a liquid crystal discharge pump to drop liquid crystal onto the substrate; Detecting an actual drop amount of the liquid crystal by measuring a temperature of a passage through which the liquid crystal flows; And A liquid crystal dropping method comprising comparing a set dropping amount with a real dropping amount and correcting the dropping amount. The method of claim 16, wherein the discharge pump, A container filled with liquid crystal; A discharge pump having a piston and sucking and discharging liquid crystal filled in the container by vertical movement of the piston; And Matching the dropping position with a liquid crystal dropping device comprising a nozzle for dropping liquid crystal discharged from the discharge pump onto a substrate; The method of claim 16, wherein the detecting the loading amount comprises: Heating a passage through which liquid crystal flows; Detecting a temperature difference by measuring a temperature at two points in the passage; And Detecting a dropping amount by the detected temperature difference. 19. The method of claim 18, wherein the temperature difference between the two points of the passage is due to heat exchange with liquid crystal flowing through the passage. 19. The method of claim 18, wherein the passage is located at the inlet side of the liquid crystal discharge pump. 19. The method of claim 18, wherein the passage is located at the outlet side of the liquid crystal discharge pump.

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