JPH07318919A - Method for sticking optical film - Google Patents

Abstract

PURPOSE:To make it possible to efficiently stick polarizing films to the substrates of liquid crystal display devices without interposing foreign matter, such as dust, and air bubbles therebetween. CONSTITUTION:A vacuum chamber 10 is internally provided with element supporting part sections 20 and film supporting sections 31 arranged on the upper side and lower side of these element supporting sections 20 and is provided with lifting mechanisms 23 to vertically move the respective film supporting sections 31 upward and downward. The liquid crystal display elements (a) are arranged at the element supporting sections 20 and are horizontally supported. The polarizing films (b) are mounted at the respective film supporting sections 31 and thereafter, the air in the vacuum chamber 10 is evacuated to maintain nearly a vacuum state. The respective film supporting sections 31 are lifted by the lifting mechanisms 23 in this vacuum state to bring the polarizing films (b) into contact with the outside surfaces of both substrates a1, a2 of the liquid crystal display elements (a). The atm. pressure is restored in the vacuum chamber 10 after this contact and the respective optical films (b) are brought into tight contact with the substrates a1, a2 of the liquid crystal display elements (a) by the pressure thereof, by which the films are stuck to the substrates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of attaching an optical film such as a polarizing film or a retardation film to a substrate of a liquid crystal display device.

[0002]

2. Description of the Related Art In a liquid crystal display device, a pair of transparent substrates (glass plates) on which electrodes for display are formed are polymer-bonded through a frame-shaped sealing material and surrounded by both the substrates and the sealing material. Liquid crystal is sealed in the area. Then, a polarizing film or a retardation film as an optical film is attached to the outer surfaces of both substrates.

FIG. 4 shows a conventional device for attaching an optical film to the outer surface of a substrate. In this figure, reference numeral 1 is a column, and a film holder 2 is pivotally attached to an upper end portion of the column 1 via a pin 3 so as to be vertically rotatable, and a pressure roller 4 is attached to a tip edge portion of the film holder 2. It is rotatably attached. An element stage 5 is provided below the film holder 2 so as to be movable in the horizontal direction.

Further, a shown in the figure is a liquid crystal display element, and this liquid crystal display element a is formed by superposing and bonding a pair of transparent substrates a1 and a2. Explaining the procedure of attaching, for example, a polarizing film b as an optical film to the liquid crystal display element a, first, as shown in FIG. 4 (A), the liquid crystal display element a is arranged on the element stage 5, and the film holder is arranged. The polarizing film b is attached to the lower surface of 2, and the edge portion on one end side of this polarizing film a is brought into contact with the lower surface of the pressure bonding roller 4.

Next, as shown in FIG. 4 (B), the film holder 2 is rotated downward about the pin 3 as a fulcrum so that the pressure roller 4 is pressed.
Is pressed against the outer surface of the edge portion on one end side of the substrate a1 in the liquid crystal display element a, and the edge portion on one end side of the polarizing film b is pressure-bonded to the surface. An adhesive is applied to the surface of the polarizing film b, and the edge of the polarizing film b on one end side is fixed to the substrate a1 via the adhesive.

Under this condition, the element stage 5 is horizontally moved leftward as shown in FIG. In accordance with this movement, the substrate a1 and the polarizing film a fixed to the substrate a1 are moved so as to be gradually separated from the pressure bonding roller 4, and the polarization film a is moved along with this movement.
Then, the entire polarizing film a is pressed against the surface of the substrate a1 through the above to adhere almost the entire outer surface of the substrate a1. In addition, 5a shown in the drawing is the element stage 5
It is a stopper for preventing the displacement movement of the liquid crystal display element a with respect to.

After the polarizing film b is attached to the outer surface of the one substrate a1 of the liquid crystal display element a in this way, the element stage 5 and the film holder 2 are returned to their original positions,
Invert the liquid crystal display element a and turn the other substrate a2 upward,
Further, a polarizing film b is newly attached to the lower surface of the film holder 2 and set. Then, in this state, the polarizing film b is attached to the outer surface of the other substrate a2 of the liquid crystal display element a by the same steps as described above.

[0008]

However, in such means, when the polarizing film is attached to the outer surface of the substrate, foreign matters such as dust floating in the working space of the polarizing film and the substrate are There is a risk that the foreign matter may enter into the surface and cause an optical defect in the liquid crystal display element due to the foreign matter. Furthermore, when sticking the polarizing film on the surface of the substrate, it is difficult to completely eliminate the air between the polarizing film and the surface of the substrate, and in the meantime, granular air bubbles due to the air remain and optical defects occur. May cause

The air bubbles generated between the polarizing film and the surface of the substrate, the liquid crystal display element is housed in the pressure pot, 5kg / cm ²
It is possible to remove the liquid crystal from the inside of the polarizing film by applying a moderate pressure, but the liquid crystal display element may be deformed so as to be crushed by the pressure when this pressure is applied.

In the conventional pasting method, after the polarizing film is pasted on the outer surface of one substrate of the liquid crystal display element, the liquid crystal display element is inverted and the polarizing film is pasted on the outer surface of the other substrate. Therefore, there is a problem that the attaching process takes time and the work efficiency is lowered.

The present invention has been made by paying attention to such a point, and an object thereof is to efficiently display a liquid crystal display on an optical film such as a polarizing film without interposing foreign matter such as dust or bubbles. An object of the present invention is to provide a method of attaching an optical film that can be attached to a substrate of an element.

[0012]

In order to achieve such an object, the present invention provides a vacuum chamber, an element supporting portion for horizontally supporting a liquid crystal display element arranged in the vacuum chamber, and an element supporting portion. A film support part is provided above and below the parts to horizontally support the optical film, and an elevating mechanism for vertically moving each film support part is provided, and a liquid crystal display element is arranged on the element support part. Then, each film supporting portion is attached with an optical film coated with an adhesive, and then the air in the vacuum chamber is exhausted to keep the vacuum chamber in a substantially vacuum state. With the lifting mechanism, the respective film supports are raised and lowered to bring the optical films into contact with the outer surfaces of both substrates of the liquid crystal display element, and after this contact, the inside of the vacuum chamber is returned to normal pressure. Wherein in the pressure Te in which each optical film was so intimately attached to the substrate of the liquid crystal display device.

Further, in this case, the element supporting portions for supporting the liquid crystal display element and the film supporting portions arranged on the upper and lower sides of the element supporting portions are provided in a plurality of stages in the vacuum chamber, and the liquid crystal is provided on the element supporting portions of each stage. It is also possible to arrange a display element, attach an optical film to each stage film support portion, and simultaneously raise and lower each film support portion to attach the optical film to both substrates of each liquid crystal display element.

[0014]

When the optical film contacts the substrate, the inside of the vacuum chamber is in a vacuum state, and therefore foreign matters such as dust do not float in the vacuum chamber, and therefore the optical film contacts the surface of the substrate. At this time, foreign matter such as dust does not enter between the optical film and the surface of the substrate, and air bubbles do not intervene. Then, after that, the inside of the vacuum chamber is returned to the normal pressure, so that the optical film surely adheres to the surface of the substrate and is firmly attached via the adhesive. Further, since the optical film is simultaneously attached to the surfaces of both substrates in the liquid crystal display element, work efficiency is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Reference numeral 10 shown in FIG. 1 is a vacuum chamber, and the vacuum chamber 10 has, for example, an opening 11 in the front surface thereof, and an opening / closing door 12 is provided in the opening 11. The vacuum chubber 10 has an exhaust hose 13
Is connected, and the vacuum pump 1
4 are provided. The opening 11 is used to open and close the door 1.
2 is closed and the vacuum pump 14 is driven to evacuate the air in the vacuum chamber 10.
The inside of 0 can be maintained in a substantially vacuum state.

Inside the vacuum chamber 10, a pair of support plates 18 are provided so as to face each other and substantially vertically, and support pieces 19 are formed in a projecting manner on a plurality of stages, for example, three stages, on the inner surface of the support plates 18. The element supporting portions 20 for horizontally supporting the liquid crystal display element a are configured by the supporting pieces 19 corresponding to each other in each stage.

The outer surface of each support plate 18 has a first
And a second elevating plate 22 are provided so as to face each other, and the elevating plates 21 and 22 can be moved up and down in opposite directions by driving by an elevating mechanism 23 provided at the lower end thereof. ing.

That is, as shown in FIG. 2, the lifting mechanism 23 includes racks 24 and 25 mounted on the inner surfaces of the lower ends of the first lifting plate 21 and the second lifting plate 22, and the racks 24 and 25. Place these racks between each other 2
Pinion 26 meshed with 4, 25, and this pinion 26
And a forward / reverse rotation type motor 27 for rotating

The motor 27 is driven to drive the pinion 2
When 6 rotates in one direction, one elevating plate 21 descends and the other elevating plate 22 rises, and the pinion 26
When is rotated in the opposite direction, one elevating plate 21 rises and the other elevating plate 22 descends.

On the inner surface of each of the elevating plates 21, 22, there are integrally formed support pieces 30 in three stages corresponding to the support pieces 19 of the support plate 18, and the corresponding support pieces 30 in each stage.
Film support 3 for horizontally supporting the optical film by
1 is configured.

As shown in FIG. 4, openings 32 are formed in the support pieces 30, respectively, and the support plate 18 is inserted into the openings 32 of the support pieces 30 of the first elevating plate 21, and the second pieces are formed. The supporting plate 18 and the first elevating plate 21 are inserted into the openings 32 of the supporting piece 30 of the elevating plate 22 of the first and second elevating plates 21, 22.
It is possible to go up and down along 8.

The uppermost supporting piece 30 of the second elevating plate 22 is disposed above the uppermost supporting piece 19 of the supporting plate 18, and the intermediate supporting piece 3 of the second elevating plate 22 is disposed.
0 is arranged between the uppermost support piece 19 and the intermediate support piece 19 of the support plate 18, and the lowermost support piece 30 of the second elevating plate 22 is the intermediate support piece of the support plate 18. It is arranged between the piece 19 and the lowermost support piece 19.

The uppermost support piece 30 of the first elevating plate 21 is the same as the uppermost support piece 19 of the support plate 18.
Is arranged between the intermediate stage support piece 30 of the elevating plate 22 and the intermediate stage support piece 30 of the first elevating plate 21.
It is arranged between the intermediate support piece 19 of the support plate 18 and the lowermost support piece 30 of the second elevating plate 22, and the lowermost support piece 30 of the first elevating plate 21 is It is arranged below the lowermost support piece 19.

Next, the procedure for attaching the polarizing film b as an optical film to the substrates a1 and a2 of the liquid crystal display element a using this attaching apparatus will be described. First, both ends of each liquid crystal display element a are placed on the edges of the support pieces 19 of each step provided on the support plate 18 and supported horizontally. Also, both ends of each polarizing film b are adhered horizontally by, for example, double-sided tape below the edge of the supporting piece 30 of each step provided on the first elevating plate 21. It is arranged so as to face the substrate a1 on the upper surface side of the liquid crystal display element a. Further, both ends of each polarizing film b are placed on the edges of the supporting pieces 30 of each stage provided on the second elevating plate 21 and supported horizontally, and these polarizing films b serve as the liquid crystal display element a. It is arranged so as to face the substrate a2 on the lower surface side.

The supporting pieces 19 of each stage provided on the support plate 18 are provided with positioning projections 19a for positioning the liquid crystal display element a at a predetermined position, and the lifting plate 21,
The polarizing film b is attached to the supporting pieces 30 of each stage provided on the plate 22.
Is provided with a positioning protrusion 30a for positioning the slab at a predetermined position. Further, each polarizing film b is coated with an adhesive on the surface facing the liquid crystal display element a.

Next, the opening 11 of the vacuum chamber 10 is closed with the opening / closing door 12. Then, drive the vacuum pump 14,
The air in the vacuum chamber 10 is exhausted to the outside through the exhaust hose 13 to maintain the inside of the vacuum chamber 10 in a substantially vacuum state.

Under this condition, the motor 27 of the lifting mechanism 23 is driven to rotate the pinion 26 in one direction. The rotation of the pinion 26 causes the first elevating plate 21 to move upward and the second elevating plate 22 to move downward.

When the first elevating plate 21 is moved upward, the polarizing film b supported by the supporting pieces 30 of each stage of the first elevating plate 22 becomes a substrate on the lower surface side of the liquid crystal display element a. Contact the surface of a2.

Further, when the second elevating plate 22 is moved downward, the polarizing film b supported by the supporting pieces 30 of each stage of the second elevating plate 22 is moved to the liquid crystal display element a.
To contact the surface of the substrate a1 on the upper surface side.

After that, air is introduced into the vacuum chamber 10 to return the inside of the vacuum chamber 10 to the normal pressure. In response to this, atmospheric pressure is applied to the surface of each polarizing film b in the vacuum chamber 10, so that the entire polarizing film b is brought into close contact with the surfaces of the substrates a1 and a2 in the liquid crystal display element a and the adhesive on the surface thereof is adhered. It is firmly attached via.

After that, the motor 27 is rotated in the reverse direction. This reverse rotation causes the first elevating plate 21 to move downward and the second elevating plate 22 to move upward. By this movement, the supporting pieces 30 of each stage provided on the first elevating plate 21 are separated from the lower surface side substrate a2 of each liquid crystal display element a to the lower side thereof, and are provided on the second elevating plate 22. Further, the supporting pieces 30 of each step are separated from the upper surface side substrate a1 of each liquid crystal display element a to the upper side thereof.

Through these steps, each liquid crystal display element a
At the same time, the polarizing film b is attached to the substrates a1 and a2. When the polarizing film b contacts the substrates a1 and a2, the inside of the vacuum chamber 10 is in a vacuum state, and therefore foreign matters such as dust do not float in the vacuum chamber 10, and therefore the polarizing film b is not covered by the substrate a1. , A2, the polarizing film b and the substrate a1
, A2, and foreign matter such as dust does not enter and bubbles do not intervene. Then, after that, the inside of the vacuum chamber 10 is returned to the normal pressure, whereby the polarizing film b
Firmly adheres to the surfaces of the substrates a1 and a2, and is firmly attached via an adhesive.

The polarizing film b is adhered to the surfaces of the substrates a1 and a2 of the liquid crystal display device a at the same time, so that the work efficiency is improved and the working efficiency is improved. Since the liquid crystal display elements a are arranged and the polarizing films b are collectively attached to the respective substrates a1 and a2 of the respective liquid crystal display elements a, the work efficiency is further improved.

The above examples are the substrates a1 and a of the liquid crystal display element a.
Although the case where the polarizing film b is attached to 2 is not limited to the case where the polarizing film b is attached, it is also possible to attach a retardation film as an optical film.

In this case, since the retardation film is attached to the outer surface of either one of the substrates a1 or a2 in the liquid crystal display element a, the retardation film is located above or below the liquid crystal display element a arranged in the element supporting portion 20. A retardation film is attached to the film supporting portion 31 arranged on the substrate, and the retardation film is attached to one of the substrates a1
Alternatively, it may be attached to the outer surface of a2, or when the polarizing film b is attached to both the substrates a1 and a2 in the liquid crystal display element a, the retardation film is attached to one of the polarizing films b in advance. It is also possible to attach the retardation film at the same time as the step of attaching the polarizing film b.

[0036]

As described above, according to the present invention, when an optical film is attached to the surface of a substrate in a liquid crystal display device, foreign matter such as dust enters between the optical film and the surface of the substrate. Or, there is no inconvenience such as the inclusion of air bubbles, the optical film can always be properly attached to the surface of the substrate, and the optical film can be attached to the surfaces of both substrates in the liquid crystal display device at the same time.
The work can be accomplished quickly and efficiently.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a sticking device used in a sticking method according to an embodiment of the present invention.

FIG. 2 is a front view showing a configuration of an elevating mechanism in the attaching device.

3 is a sectional view taken along the line AA in FIG.

FIG. 4 is a side view showing a conventional sticking device.

[Explanation of symbols]

 a ... Liquid crystal display elements a1, a2 ... Substrate b ... Polarizing film 10 ... Vacuum chamber 14 ... Vacuum pump 20 ... Element support 23 ... Lifting mechanism 31 ... Film support

Claims (2)

[Claims] 1. A vacuum chamber, an element support portion for horizontally supporting a liquid crystal display element arranged in the vacuum chamber, and an optical film horizontally supported by being arranged above and below the element support portion. A film supporting part to be provided, and an elevating mechanism for vertically moving each of the film supporting parts are provided, and a liquid crystal display element is disposed in the element supporting part and horizontally supported, and an adhesive is applied to each of the film supporting parts. The coated optical film is attached, and then the air in the vacuum chamber is exhausted to maintain a substantially vacuum state in the vacuum chamber, and under this state, the respective film support portions are moved up and down by the elevating mechanism. The optical film is brought into contact with the outer surfaces of both substrates of the liquid crystal display element, and after this contact, the inside of the vacuum chamber is returned to normal pressure, and the pressure causes the respective optical films to come into close contact with the substrate of the liquid crystal display element. Method of bonding an optical film characterized in that paste by. 2. An element supporting portion for supporting a liquid crystal display element, and film supporting portions arranged on the upper and lower sides of the element supporting portion are provided in a plurality of stages in a vacuum chamber, and the liquid crystal display is provided on the element supporting portion of each stage. 2. An element is arranged, an optical film is attached to each stage film support portion, and each film support portion is simultaneously moved up and down to attach the optical film to both substrates of each liquid crystal display element. How to attach the optical film.