JP2005274779A - Apparatus and method for manufacturing liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply a sealing material in a short time with position precision without causing dripping by efficiently carrying out steps of liquid crystal from injection, liquid crystal cell pressure application, sealing material coating, to curing by ultraviolet-ray setting for a plurality of liquid crystal cells. <P>SOLUTION: The plurality of liquid crystal cells are set in a cassette with injection holes down. After liquid crystal is injected into the liquid crystal cells by using a vacuum injecting method, pressure is applied to the liquid crystal cells to wipe excessive liquid crystal away and the sealing material is applied still in the pressure-applied state. In the sealing material coating step, a sealing material dish having the sealing material linearly at positions meeting injection hole positions is arranged at a lower part of the liquid crystal cells and the sealing material dish is elevated to apply the sealing material. While the liquid crystal cells having coated with the sealing material are less pressed than in the sealing material coating, the applied sealing material is irradiated with ultraviolet rays. The series of steps are carried out while the liquid crystal cells are set in the one cassette. Further, the sealing material supplied to the sealing material dish is vibrated to uniformly be leveled. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for manufacturing a liquid crystal display element, in which liquid crystal is injected into a liquid crystal cell, and the inlet is sealed by applying a sealing material while pressurizing the liquid crystal cell, and then curing the applied sealing material by ultraviolet curing. , And its manufacturing method.

  Conventionally, as this kind of manufacturing apparatus and manufacturing method in a liquid crystal display device, those described in Patent Document 1 or Patent Document 2 are known.

  In both cases, when pressure sealing is performed in the next process after the liquid crystal is injected into the liquid crystal cell, an operation of refilling into a specific cassette occurs. When this refilling operation is performed, the liquid crystal cell may be brought into contact with the outer frame of the cassette to cause a crack in the liquid crystal cell. Further, when the number of liquid crystal cells to be packed in the cassette is large, it takes time to refill.

With respect to Patent Document 1, when application is performed to each injection port of a large number of stacked liquid crystal cells by performing the sealing operation with a dispense nozzle, time is required for the operation. Further, since the sealing material itself is a liquid having a certain degree of viscosity, there is a difference between the first applied sealing material application width and the last applied sealing material application width after ultraviolet irradiation. This is a variation in the external dimensions of the completed liquid crystal display device. FIG. 3 shows the case where the sealing material is applied by the conventional technique, and the sealing width (L ₀ ) applied first (L ₁ ) and the last applied (L ₂ ). Thus, the length L ₁ > L ₂ is satisfied.

  Further, if the application position is shifted with respect to the injection port, the portion in which the sealing material cannot cover the injection port becomes defective because air enters the liquid crystal cell. FIG. 4 shows a state in which the sealing material is applied by the conventional technique and the sealing material is displaced from the injection port. Furthermore, since the sealing material is applied with the injection port facing upward, it will sag downwards until it is cured after application, and when irradiated with ultraviolet light in that state, the sealing material is applied to the front and back surfaces of the glass. Hardens and adheres. FIG. 5 shows a state in which the sealing material is applied by the conventional technique, and the applied sealing material hangs down in the display surface direction. Similarly, Patent Document 2 is applied with the liquid crystal injection port facing upward. FIG. 2 shows how it is applied by the prior art. The injection port is set upward in the cassette, and the dispensing nozzle is used to apply to a large number of injection ports.

JP 2003-75847 A JP 2003-29274 A

  The problem to be solved by the present invention is to solve the problems in the conventional apparatus or method for manufacturing a liquid crystal display device as described in the background art. That is, if the liquid crystal cell is cracked or the number of liquid crystal cells to be packed in the cassette is large, it takes time to refill, the sealing material application width applied first, and the sealing material application width applied last. The difference in the size of the liquid crystal display device due to the difference after UV irradiation is caused, the air enters the liquid crystal cell and becomes defective, and the sealing material hardens on the front and back surfaces of the glass. It is to solve problems such as adhesion. An object of the present invention is to provide a liquid crystal cell in which a sealing material can be accurately applied to a liquid crystal inlet, and to which no sealing material is applied, and at the same time to improve working efficiency.

  In order to achieve the above object, a manufacturing apparatus and a manufacturing method of a liquid crystal display element of the present invention are configured as follows. A pair of substrates having respective electrodes are opposed to each other, and a liquid crystal cell sealed by forming a liquid crystal injection port with a sealing material around the substrate is set so that the injection port faces downward. After injecting liquid crystal into the liquid crystal cell using a vacuum injection method, the liquid crystal cell is pressurized to wipe off excess liquid crystal, and a sealing material is applied while maintaining the pressure. In the sealing material application step, a sealing material plate in which a sealing material is linearly arranged at a position that matches the inlet position is disposed below the liquid crystal cell, and the sealing material plate is raised. The sealing material is applied by The applied sealing material is irradiated with ultraviolet rays in a state where the liquid crystal cell to which the sealing material has been applied is pressurized at a pressure smaller than the pressure at which the sealing material is applied. These series of steps are performed with the liquid crystal cell set in one cassette.

  According to the liquid crystal display element manufacturing apparatus and method of the present invention, a plurality of liquid crystal cells can be processed consistently in a short time from liquid crystal injection to pressure sealing and ultraviolet irradiation. Moreover, the work of replacing the liquid crystal cell with the cassette can be omitted, and defects such as glass breakage during the replacement can be prevented. In particular, in the sealing material application process, since the sealing material is applied and the ultraviolet rays are irradiated with the injection port facing downward, the sealing material does not sag in the display area direction. Furthermore, it is possible to apply the sealing material placed in a straight line on the sealing material tray to the numerous inlets at a time so that the inlet can be applied with a certain width and in a short time with high positional accuracy. . By automatically replenishing the sealing material onto the sealing material tray, the work can be omitted.

Embodiment 1
FIG. 1 shows a liquid crystal cell 1 before liquid crystal is injected. 1A is a plan view of the liquid crystal cell 1, and FIG. 1B is a side view of the liquid crystal cell 1. The liquid crystal cell 1 has a pair of substrates each having an electrode facing each other, and the periphery thereof is sealed with a sealing material 2 provided with a liquid crystal injection port 3. A certain gap is secured in the cell by the spacer 4.

  6 and 7 show the state of the liquid crystal cell housed in the cassette 9. The plurality of liquid crystal cells 1 are set in the cassette 9 so that the inlet 3 is exposed. A cushion sheet 7 is sandwiched between the liquid crystal cell and the liquid crystal cell for the purpose of preventing damage to the liquid crystal cell due to contact. Pressure plates 8 for applying a load equally to the liquid crystal cells are installed at both ends of the liquid crystal cell. Even when the number of liquid crystal cells to be stored is changed on one plate, the liquid crystal cells have cushion sheets. A spring 10 is attached so that it can be fixed tightly in between.

  A process and apparatus for injecting liquid crystal into a liquid crystal cell using a vacuum injection method will be described. When the cassette 9 in which the liquid crystal cell is set is set in the inlet of the apparatus and manufacturing is started, the cassette 9 in which the liquid crystal cell is set moves to the liquid crystal injection step shown in FIG. The liquid crystal injection chamber 19 is provided with a liquid crystal dish on which liquid crystal is placed below. The chamber is sealed and evacuated until a vacuum pressure of about 0.2 to 0.7 torr is reached by a vacuum pump. After reaching a certain vacuum pressure, the liquid-filled pouring tray is held for a certain time and ascends to the vicinity of the liquid crystal cell inlet inserted in the cassette 9, and the liquid crystal comes into contact with the liquid crystal cell inlet. In the liquid crystal dish, a groove is formed in accordance with the inlet position of the liquid crystal cell to be processed, and liquid crystal is placed in the groove. After 30 seconds to 120 seconds after bringing the liquid crystal into contact with the inlet, the pressure in the chamber is returned to normal pressure by sucking dry air or gaseous nitrogen into the chamber. Then, the liquid crystal is injected from the injection port of the liquid crystal cell by leaving it for a certain period of time. At this time, the exhaust time, the time from the rise of the liquid crystal dish to the start of intake, and the intake time can be arbitrarily set according to the size of the liquid crystal cell to be processed.

  The liquid crystal in the liquid crystal cell immediately after the liquid crystal injection is completed exceeds the optimum amount and is larger than the proper gap value. FIG. 14 shows a liquid crystal cell immediately after liquid crystal is injected.

  The cassette 9 in which the liquid crystal cell in which the liquid crystal injection has been completed is moved to the pressurizing / wiping process shown in FIG.

The pressurizing / wiping process will be described. The cassette 9 containing the liquid crystal cell moved in this step is moved to any one of the four pressurizing positions, and is fixed by the positioning fixing unit 20 so that the cassette 9 does not move. After that, as shown in FIG. 8, the liquid crystal cell is pressurized via the pressure plate 8 in the cassette 9 by the air cylinder 13 with the support rod 12 mounted below. The support rod 12 and the air cylinder 13 are disposed below the cassette 9 so as not to come into contact with each other when the cassette 9 is moved, and are raised and pressurized when pressurized. The actual load applied to the plate in the cassette 9 at this time is V ₀ . The pressing force and pressurizing time can be freely set within an appropriate range.

  After pressurizing for a certain period of time with the air cylinder 13, as shown in FIG. 9, the liquid crystal wiping mechanism 14 equipped with paper wound in a roll shape and equipped below is used to remove excess liquid crystal from the inlet. Wipe off. At this time, the support rod 12 and the air cylinder 13 that pressurize the liquid crystal cell are still pressurized. The liquid crystal wiping mechanism 14 can move along the injection port, and can cope with a liquid crystal cell having a large number of injection ports. The wiped paper is rolled up and new paper appears whenever the next cassette is processed, wiping the inlet. The traveling speed of the roll paper during wiping can be freely set within an appropriate range. In the pressurizing / wiping process, four cassettes can be processed at a time. In this embodiment, paper is used to wipe off the liquid crystal, but cloth may be used as long as it has a property of sucking liquid crystal.

  FIG. 10 shows a state in which pressure is held by the pressure plate 8 for the purpose of transporting the liquid crystal cell to the next process while holding the pressure. After wiping off the excess liquid crystal that has come out of the injection port in this way, the set screw 11 provided in the cassette 9 is tightened and fixed. The pressurization holding time at this time is usually 5 to 15 minutes and can be set freely.

  After tightening the set screw and fixing the liquid crystal cell with the pressure plate, a completion instruction is given to the apparatus. Thereafter, the cassette 9 containing the liquid crystal cell in which the pressure is maintained is conveyed to a sealing material application process shown in FIG.

In the sealing material application process, as shown in FIGS. 11 and 15, the dish 15 on which the sealing material 5 is linearly placed is placed below so as to match the position of the inlet of the liquid crystal cell. . The dish 15 on which the sealing material is stacked is raised at the inlet of the pressurized liquid crystal cell, and the sealing material is applied by bringing the sealing material 5 into contact with the inlet. The rising end position of the sealing material tray 15 can be freely set, and the sealing width (L ₀ ) can be adjusted by the distance between the inlet of the liquid crystal cell and the sealing material tray rising end position. Since the sealing material plate 15 used at this time can be the same as the liquid crystal plate used at the time of liquid crystal injection, it is not necessary to design and manufacture a new plate. Thereby, it is possible to process liquid crystal cells of various sizes having different inlet widths. At this time, the liquid crystal cell is kept pressurized by the set screw. The cassette 9 containing the liquid crystal cell in which the application of the sealing material has been completed is transported to the next process while the pressure is maintained. After that, while the next cassette 9 moves to the application position, the sealing material is supplied to a predetermined position of the sealing material tray.

The ultraviolet irradiation process shown in FIG. 13 will be described. As shown in FIG. 12, the transported cassette 9 moves to a process in which the ultraviolet irradiation mechanism 18 is installed at the lower portion, and is fixed by the positioning fixing unit 20. The air cylinder 13 with the support rod 12 arranged at the lower part of the cassette 9 rises, and the liquid crystal cell is pressurized via the pressure plate 8 in the cassette 9. At this time, if the actual load applied to the pressure plate 8 in the cassette 9 is V ₁ , the cylinder is set so that V ₁ <V ₀ (V ₀ is the actual load pressurized on the liquid crystal cell in the pressurizing step). Pressure can be set freely. In this state, by loosening the set screw 11 of the pressure plate in the cassette 9, the sealing material applied to the injection port of the liquid crystal cell is drawn into the display area side from the injection port.

  Then, ultraviolet irradiation is started and ultraviolet rays are irradiated from below to cure the sealing material. The irradiation time of ultraviolet rays can be set freely.

  The cassette 9 containing the liquid crystal cell irradiated with ultraviolet rays for a set time moves to the takeout port shown in FIG. 13, and the liquid crystal injection pressure sealing is completed.

  FIG. 18 shows a flow chart of the liquid crystal injection pressure sealing device.

Embodiment 2
In the present embodiment, the steps until the sealing material is applied are the same as those in the first embodiment. Liquid crystal is injected into the liquid crystal panel set in the cassette by a vacuum injection method, pressurized to wipe off excess liquid crystal, and a sealing material is applied in a state where the pressure is maintained. The cassette 9 containing the liquid crystal cell in which application of the sealing material has been completed is transported to the next process while the pressure is maintained. The present embodiment is characterized in a step of supplying the sealing material to the sealing material tray after applying the sealing material.

  16 and 17 show how the sealing material is supplied to the sealing material tray. The cassette 9 that has been applied is transferred to the next process, and the sealing material 5 is supplied to the sealing material plate 15 while the next cassette moves to the application position. The air pressurization type dispensing nozzle 16 containing the stopper moves to the position where the sealing material of the sealing material tray 15 is stacked, and supplies the sealing material 5. The syringe 17 of the dispensing nozzle 16 contains the sealing material 5. As shown in FIG. 17, the dispensing nozzle 16 is set so as to move in accordance with the position where the sealing material of the sealing material tray is stacked by the moving mechanism. Further, the amount of the sealing material supplied from the dispensing nozzle can be freely adjusted by changing the air pressure supplied to the syringe 17 containing the sealing material. When the sealing material 5 supplied in this manner is supplied, the height is locally increased as shown in FIG. 16, so that the sealing material plate is vibrated by the vibration mechanism 21 by the vibration motor, and is evenly distributed. It is leveled to a certain height.

  The processes after the ultraviolet irradiation process are the same as those in the first embodiment. In a state where the pressure is lower than the pressure when the sealing material is applied, the sealing material is cured by irradiating with ultraviolet rays. After that, it moves to the takeout port shown in FIG. 13 and the liquid crystal injection pressure sealing is completed.

  FIG. 19 shows a flow chart of the liquid crystal injection pressure sealing device.

It is the top view and side view which show the liquid crystal cell before liquid crystal injection. It is a figure which shows the example of a sealing method using the dispensing nozzle of a prior art. It is a figure which shows the state of the sealing material apply | coated to the injection port. It is a figure which shows the state (application | positioning position shift | offset | difference) of the sealing material apply | coated to the injection port by the prior art. It is a figure which shows the state (sealing material sagging) of the sealing material apply | coated to the injection port by the prior art. It is a perspective view of the liquid crystal cell accommodated in the cassette of this invention. It is a top view of the liquid crystal cell accommodated in the cassette of this invention. The side view which shows a liquid crystal cell being pressurized in a pressurization and wiping off process. It is a side view which shows the liquid crystal being wiped off by the pressurization and wiping process. It is a side view which shows the state by which pressurization of the liquid crystal cell was hold | maintained by screwing of the cassette. It is a side view which shows a sealing material application process. It is a side view which shows an ultraviolet irradiation process. It is a layout figure of the liquid crystal cell manufacturing apparatus of this invention. It is a side view of the liquid crystal cell after a liquid crystal injection process is completed. It is a top view which shows a sealing material application | coating process. It is a side view which shows a sealing material being replenished to a sealing material tray with a dispensing nozzle. It is a top view which shows a sealing material being replenished to a sealing material tray with a dispensing nozzle. It is a flowchart which shows the method of Embodiment 1 of this invention. It is a flowchart which shows the method of Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal cell 2 Sealing material 3 Liquid crystal inlet 4 Spacer 5 Sealing material 7 Cushion sheet 8 Pressure plate 9 Cassette 10 Spring 11 Set screw 12 Support rod 13 Air cylinder 14 Liquid crystal wiping mechanism 15 Sealing material plate 16 Dispense nozzle 17 Syringe 18 Ultraviolet irradiation mechanism 19 Liquid crystal injection chamber 20 Positioning and fixing part 21 Vibration mechanism

Claims (10)

A cassette for storing a liquid crystal cell in which a liquid crystal injection port is formed with a sealing material with the liquid crystal injection port set downward;
A mechanism for transporting the cassette from the apparatus inlet to the liquid crystal injection chamber;
A liquid crystal injection mechanism for injecting liquid crystal into the liquid crystal cell from the liquid crystal injection port using a vacuum injection method;
A transport mechanism for moving the cassette containing the liquid crystal cell in which liquid crystal injection has been completed to the pressurizing step;
A mechanism for pressurizing the liquid crystal cell with an air cylinder;
A control device for controlling the pressing force of the pressurizing mechanism;
A mechanism for wiping off excess liquid crystal from the liquid crystal inlet;
A pressure holding and conveying mechanism that conveys the cassette containing the liquid crystal cell to a sealing material application position while holding the pressure;
A mechanism for applying a sealing material;
A transport mechanism for transporting the cassette containing the liquid crystal cell coated with the sealing material to the decompression process;
A mechanism for depressurizing the liquid crystal cell pressurized by the air cylinder;
A control device for controlling the decompression force of the decompression mechanism;
An ultraviolet irradiation mechanism for irradiating the applied sealing material with ultraviolet rays under reduced pressure;
A control device for controlling the ultraviolet irradiation amount of the ultraviolet irradiation mechanism;
A mechanism for transporting the cassette containing the liquid crystal cell that has been irradiated with ultraviolet rays to the device exit;
An apparatus for manufacturing a liquid crystal display element comprising: The liquid crystal display device manufacturing method according to claim 1, wherein the cassette for storing the liquid crystal cell is capable of storing a plurality of liquid crystal cells with a cushioning material interposed between the liquid crystal cells to prevent direct contact between the liquid crystal cells. apparatus. The cassette is equipped with a spring for accommodating a plurality of liquid crystal cells in a stacked manner, a plate for evenly transmitting the applied pressure to the cells during pressurization, and a set screw for holding the pressurization. Item 3. A liquid crystal display device manufacturing apparatus according to Item 2. The apparatus for manufacturing a liquid crystal display element according to claim 1, wherein the liquid crystal wiping mechanism is provided with roll paper at a lower portion of a liquid layer cell stored in the cassette. The sealing material application mechanism is equipped with a dish placed in a straight line so that the sealing material matches the inlet position at the bottom of the liquid layer cell stored in the cassette. The apparatus for manufacturing a liquid crystal display element according to claim 1, further comprising an up-and-down driving unit for moving up and down. The sealing material application mechanism is
Under the liquid layer cell stored in the cassette, a dish placed linearly so that the sealing material matches the inlet position;
A vertical drive unit for moving the sealing material tray up and down;
A movable air pressurizing dispense nozzle for supplying a sealing material to the sealing material tray;
A vibration generating mechanism for uniformizing the height of the encapsulated sealing material at the bottom of the encapsulating material plate,
The apparatus for manufacturing a liquid crystal display element according to claim 1, wherein: The said sealing material tray is a manufacturing apparatus of the liquid crystal display element of Claim 1 which uses the same thing as a liquid crystal tray. A loading and transporting step of transporting a liquid crystal cell in which a liquid crystal injection port is formed with a sealing material, with the liquid crystal injection port facing downward, to a liquid crystal injection chamber;
A liquid crystal injection step of injecting liquid crystal from the injection port of the liquid crystal cell using a vacuum injection method;
A transport step of moving a cassette containing a liquid crystal cell filled with liquid crystal to a pressurization step;
Pressurized wiping process to pressurize the liquid crystal cell and wipe off excess liquid crystal,
A transport step for transporting the cassette containing the pressurized liquid crystal cell to the sealing material application step while maintaining the pressurization;
A sealing material plate in which a sealing material is linearly arranged at a position matching the inlet position is disposed at the lower part of the liquid crystal cell, and the sealing material is applied by raising the sealing material plate. And a process of
A transport process for transporting a cassette containing a liquid crystal cell coated with a sealing material to a decompression process;
In a state where the liquid crystal cell is decompressed, an ultraviolet irradiation step of irradiating the applied sealing material with ultraviolet rays,
A transport step for transporting the cassette containing the liquid crystal cell completed with ultraviolet irradiation to the outlet;
A method for manufacturing a liquid crystal display device comprising: In the sealing material application step, after the sealing material is applied to the liquid crystal inlet, the sealing material is applied by an air pressure type dispensing nozzle while the next cassette arrives at the sealing material application step. A certain amount of sealing material is replenished to the dish, and the sealing material dish is made uniform in height by supplying the sealing material dish with vibration by a vibration generating mechanism. The manufacturing method of the liquid crystal display element of Claim 8. 10. The liquid crystal display element according to claim 8, wherein the cassette for storing the liquid crystal cell is capable of storing a plurality of liquid crystal cells with a cushioning material interposed between the liquid crystal cells to prevent direct contact between the liquid crystal cells. Manufacturing method.

Images