JP3313422B2 - Film lamination method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laminating films used for forming a composite film for optical compensation of an STN type liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been required to increase the twist angle of liquid crystal molecules by 180 due to a demand for enlargement of a display screen.
A device having an angle of about 270 degrees (generally referred to as an STN type liquid crystal display device) has been developed. However, this STN-type liquid crystal display device has a drawback that monochrome display cannot be performed because coloring is caused by birefringence of liquid crystal molecules. In view of this, a method has been proposed in which another color achromatism liquid crystal cell is added as an optical compensator to the STN-type liquid crystal cell to eliminate coloration and to enable monochrome display. As the number of cells increases, the cost increases and the economy is inferior.

Recently, a method using a retardation film instead of the achromatic liquid crystal cell as described above has been proposed and implemented. The retardation film has birefringence, and the light passing through it has a difference in the refractive index in two directions perpendicular to each other, so that a phase difference occurs between the orthogonal rays after transmission. Utilizing this property, the optical axis of the polarizing plate and the optical axis of the retardation film are appropriately set and bonded, and the STN liquid crystal cell is sandwiched between the composite films to realize a black and white display of the STN liquid crystal display device. are doing.

As a method of forming a composite film as described above by laminating two films, for example, Japanese Utility Model Application
As disclosed in Japanese Patent No. 29029, the lower film is suction-held on the upper surface of the lower support member, the upper film is suction-held on the lower surface of the upper support member, and one end of the upper film is mounted on the upper support member. A configuration in which the upper support member is horizontally moved along the upper surface of the lower support member while holding this state, and the upper film is bonded to the lower film while maintaining this state, has been proposed. ing.

[0005]

However, the conventional method of this embodiment has the following problems. That is, in order to prevent the upper film from falling off, the upper film is stuck to the upper support member in a state where the upper film is strongly sucked and held. Therefore, a tensile stress is applied to the upper film, and distortion is likely to occur. In particular, when laminating a polarizing plate and a retardation film used in a liquid crystal display, the optical axis changes when distortion occurs as a whole or locally in the retardation film. This causes a problem such as the occurrence of

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a film bonding method capable of bonding two films without applying stress.

[0007]

The present invention has the following configuration in order to achieve the above object. That is, the present invention is a method of bonding a first film and a second film each having an adhesive layer formed on at least one bonding surface, wherein the first film is placed on the upper surface of the lower support member, 2. The film is sucked and held on the lower surface of the upper support member, and one end of the first film on the lower support member is pressed against one end of the upper second film by an attaching roller, and in this state, the lower support member is placed on the lower surface of the upper support member. Is moved along, the sticking roller is driven,
A mode in which the first film is attached to the film is adopted.

[0008]

The operation of the present invention is as follows. Lower first
Pressing the film against the upper second film, the first
Since the two films are bonded by moving the film, there is no need to strongly attract and hold the lower first film to the lower support member, and almost no unnecessary stress is applied to the lower first film.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an entire plane of an automatic laminating apparatus for forming a composite film for optical compensation used in an STN type liquid crystal display device.

A retardation film F ₁ as a first film to be laminated by this apparatus is a rectangular film cut in advance so that an optical axis is in a predetermined direction, and an adhesive layer is formed on a lamination surface. While being formed, the protective film f is stuck on it. Further, a polarizing plate F as a second film to be bonded to the retardation film F ₁
Reference numeral ₂ denotes a rectangular film cut in advance so that the optical axis is in a predetermined direction, and a protective film f is also attached to the bonding surface.

[0011] The automatic film laminating apparatus, protective said film f in the above retardation film F ₁ first to keep thickness of approximately 200 sheets film accommodating portion 1, the polarizing plate F protective film f in the above ₂ 200 sheets approximately laminated second advance film accommodating portion 2, the first film transport mechanism 3 that horizontally conveyed from the first top layer of the film accommodating portion 1 taken out one by one phase difference film F _1, the second film Storage section 2
The second film transport mechanism 4 for horizontal conveyance is taken out one by one polarizing plate F ₂ from the uppermost layer of the first film transport mechanism 3
In is conveyed placed receives a phase difference film F ₁ has been peeled table 5, the second film transport mechanism sticking table 6 for placing receive polarizer F ₂ that has been conveyed by 4, the phase difference on the separation table 4 the first protective film peeling mechanism 7, the second protective film peeling mechanism 8, Paste and lower separation table 4 table to peel recovering protective film joining the polarizing plate F ₂ on the table 6 to peel recovering the protective film from the film F ₁ 6 and a composite film transport mechanism 11 that can reciprocate and swing between the lower side of the attaching table 6 and the upper side of the unloading conveyor 10, and the like. A detailed configuration of each unit will be described below.

FIGS. 2 and 3 show the structure of the first film storage 1 and the first film transport mechanism 3. FIG. The first film storage unit 1 includes a mounting table 1 that is sequentially moved up and down on a base frame 12 by an actuator (not shown).
3, a pair of fixed guide 14 from two directions perpendicular to the retardation film F ₁ group on the mounting table 13 is erected on the base frame 12 for positioning guide, the retardation film F ₁ group on the mounting table 13 each A movable guide 16 is provided which is driven by an air cylinder 15 so as to be pressed against the fixed guide 14. In addition, on the side of the first film storage unit 1, similarly, the lifting table 17, the fixed guide 18, the air cylinder 19
Is provided with a film collecting unit 21 having a movable guide 20 driven by the above.

The first film transport mechanism 3 includes a movable base 2 supported to be horizontally movable left and right along a guide rail 22.
3. A screw shaft 24 for feeding the movable base 23 by screw, an electric motor 25 for driving the screw shaft 24 in forward and reverse rotations, and the movable base 23 are provided so as to be able to swing forward and backward by 45 ° horizontally around the longitudinal axis a. A swing arm 26, an air cylinder 27 for swinging and driving the swing arm 26, and a first
The lifting bracket 3 supported so as to be liftable via an air cylinder 28, a second air cylinder 29, and a guide 30.
1, a plurality of suction pads 32 provided on the movable bracket 31 and the like.

The constructions of the second film accommodating section 2 and the second film transport mechanism 4 are the same as those of the first film accommodating section 1 and the first film transport mechanism 3, and a description thereof will be omitted. In addition, a film collection unit 33 having the same configuration is provided on the side of the second film storage unit 2.

FIGS. 4 and 5 show the structure of the peeling table 5. Large This separation table 5 comprising, are deployed retardation film F ₁ so that the diagonal line is sucked and held is placed in an inclined position towards the left-right direction, the three corner portions of the phase difference film F ₁ The first table portion 5a for supporting the portion by suction, and the second table portion for supporting the remaining corner portion by suction.
It is configured in a divided structure with the table section 5b. The first table portion 5a is supported by a movable table 37 driven left and right by an air cylinder 36 along a guide rail 35 so as to be vertically oscillated by an air cylinder 38 around a front and rear horizontal axis b. I have. On the other hand, the second table section 5b
Is supported by a movable table 41 driven left and right by an air cylinder 40 along a guide rail 39 so as to be vertically oscillated by an air cylinder 42 around a front-rear horizontal axis c. Also, facing two orthogonal sides of the peeling table 5,
Positioning guide 44 driven forward and backward by air cylinder 43
Has been deployed.

As shown in FIG. 1, the sticking table 6 is arranged so that the polarizing plate F ₂ is placed in an inclined posture in which the diagonal line is directed to the left and right, and is held by vacuum suction.
It is configured so as to be capable of reversing and positioning around a horizontal axis d at an angle of 45 ° via an electric motor 45 and an index mechanism 46, and its upper and lower surfaces are formed as vacuum suction surfaces. In addition, a positioning guide 48 that can be advanced and retracted by the air cylinder 47 is provided facing the two orthogonal sides.

FIGS. 7 to 10 show the structure of the first protective film peeling mechanism 7. FIG. The frame 50 of the first protective film peeling mechanism 7 includes a pair of front and rear guide rails 5.
The movable frame is configured to be movable horizontally in the left and right direction along a screw shaft 1, and is moved left and right by a screw shaft 53 driven forward and reverse by an electric motor 52. Then, on the movable frame 50, a delivery roller 55 for feeding out the highly adhesive peeling tape T from the tape roll 54, an electric motor 56 for driving the same, and peeling off the released peeling tape T such that the adhesive surface faces down. A group of guide rollers 58 for guiding and supplying to the head 57, a guide frame 59 for guiding the peeling tape T that is reversed and returned from the peeling head 57, a feed roller 60 for driving and transporting the returned peeling tape T, and a belt interlocked with the rollers. A drive mechanism 61 and the like are provided. The base frame 12 is provided with a recovery reel 64 that guides and returns the returned peeling tape T via the guide roller 62 and the guide plate 63, an electric motor 65 that drives the recovery reel 64, and the like. The peeling head 57
As shown in FIG. 10, the peeling tape T guides and reverses the lower surface of the wide knife edge plate 66 from the lower surface to the upper surface thereof.

Since the second protective film peeling mechanism 8 has the same configuration as the first protective film peeling mechanism 7, the description is omitted.

FIGS. 12 and 13 show the structure of the transfer table 9. FIG. The transfer table 9 is a movable table 7 that can be moved up and down via an air cylinder 70 and a guide 71.
2, is supported by an air cylinder 73 so as to be able to swing up and down around a horizontal axis e.
It is configured to be horizontally movable via a screw shaft 75 and a guide rail 76 that are driven forward and reverse by an electric motor 74. Further, the guide rail 76 is mounted on a turntable 78 that can be turned around a vertical axis g by a direct motor 77, and the underframe 7 that supports the turntable 78.
9 is horizontally moved back and forth via a screw shaft 82 driven forward and backward by a guide rail 80 and an electric motor 81. At the front of the transfer table 9, a sticking roller 84 that is moved up and down by an air cylinder 83 is provided.

The automatic laminating apparatus according to the present embodiment is configured as described above. Next, the film laminating operation will be described in the order of the steps.

(1) Phase difference film take-out step The first and second air cylinders 28 and 29 of the first film transport device 3 located immediately above the first film storage section 1 are extended, and the vacuum suction pad 32 is moved to the second position. 1 film is laminated in the housing section 1 is lowered onto the retardation film F ₁ waiting a predetermined height. After adsorbing the retardation film F ₁ of the top layer, lifting only the second air cylinder 29 is contracted retardation film F ₁ to a predetermined height, the presence of two adsorption confirmed by thickness detecting means (not shown), where Is done. In addition,
When the suction by the vacuum suction pad 32 is performed, the mounting table 13 of the first film storage unit 1 is slightly lowered to prevent the two sheets from being suctioned.

When it is confirmed that no two sheets are adsorbed, the first
After the air cylinder 28 contracts and the air cylinder 27 contracts and the swing arm 26 is rotated 45 ° counterclockwise, the forward rotation screw feed drive is started, and the phase difference film F ₁ becomes 45 °. It is supplied and placed on the peeling table 5 in a deflected state.

In the case where two sheets are suctioned, the vacuum suction pad 32 is moved onto the film collecting section 21 by the reverse screw feed drive, and the two suctioned retardation films F ₁ are discharged onto the mounting table 17. Then, returning to the first film storage section 1 again, the film taking-out operation is repeated.

(2) Polarizing Plate Take-Out Step The supply of the polarizing plate F ₂ from the second film storage section 2 to the attaching table 6 is performed in the same manner as described above, and the description is omitted.

(3) Peeling Process of the Protective Film of the Retardation Film The retardation film F ₁ supplied and placed on the release table 5
Is set at a predetermined position, and then the first table portion 5
a and the upper surface of the second table portion 5b.

Next, the first film peeling mechanism 7 is advanced to a predetermined position, and the peeling head 5 is moved by the air cylinder 67.
7 is lowered onto the left corner of the retardation film F _1, as shown in FIG. 11, the peeling tape T retardation film F ₁
Is pressed on the protective film f stuck on the upper surface of.

[0027] Then, the peeling head 57 along with the movable frame 50 moves backward horizontally moves along the retardation film F _1. At this time, the delivery roller 55 is driven and the release tape T is moved by the same amount as the moving amount of the movable frame 50.
Is moved toward the peeling head 57, and a pinion gear 85 provided in the drive mechanism 61 is relatively rotated with the retreating movement of the movable frame 50 so as to engage with a rack 86 fixed to the base frame 12.
Is transmitted to the feed roller 60 via the gear 87 and the belt transmission 88, the feed roller 60 is driven to rotate counterclockwise, and the peeling tape T is fed by the same amount as the moving amount of the peeling head 57. , protective film f Yuku sent back rearwardly raised turning from the corner of the retardation film F _1. The protection film f flipped up along with the return of the protection film f is sent in a state of being narrowly bent upward by the guide of the guide frame 59, and is wound and collected together with the peeling tape T on the collection reel 64.

Next, when the movable frame 50 moves forward on the peeling table 5, the clutch 8 provided in the drive mechanism 61 is provided.
9, the feed roller 60 is fixed even if the pinion gear 85 is rotated by the advance of the movable frame 50 by operating the brake 90 on the lower side.
The peeling tape T wound on the collection reel 64 is pulled out as the movable frame 50 advances.

(4) Step of peeling protective film from polarizing plate Protective film f from polarizing plate F ₂ on application table 6
Is performed in the same manner as described above, and a description thereof will be omitted.

(5) Step of Transferring the Retardation Film to the Transfer Table During the protective film peeling step, the transport table 9 stands by under the peeling table 5 at a position deflected by 45 °. When the protective film peeling process is completed as described above,
First, as shown in FIG. 6A, suction is released only from the first table portion 5a, and at the same time, the air cylinder 38 contracts and the free end side of the first table portion 5a swings downward. Next, the air cylinder 36 extends, and FIG.
As shown in (1), the first table portion 5a retreats horizontally and the retardation film F1 is received on the transport table 9. Thereafter, as shown in FIG. 6C, the air cylinder 42 extends and the free end side of the second table portion 5b swings downward. Next, as shown in FIG. 6 (d), the second table portion 5b horizontally moves backward and the retardation film F
1 The whole is transferred onto the transfer table 9 with the adhesive surface facing up.

When the transfer onto the transfer table 9 is completed,
After film positioning is again operating the movable guide 44, and vacuum suction phase difference film F ₁ on the upper surface of the conveying table 9, moving the conveying table 9 back and forth, left and right movement, and the turning operation is not the joining with the table 6 and is opposed to the lower surface thereof at an appropriate small interval (about several mm). At this time, one side of the phase difference film F ₁ positioned and fixed on the transport table 9 is set to protrude from the edge of the table and to protrude above the attaching roller 84.

[0032] (6) while the transfer and positioning of the conveying table 9 of the retardation film F ₁ as the positioning stand stroke above polarizing plate is being performed, even polarizing plate F ₂ on joining table 6 positioned is held by suction is, before the conveying table 9 comes under the joining table 6, the joining table 6 is turned upside down, the polarizing plate F ₂ is downwardly attracted to and held on the lower surface of the joining table 6 as an upper support member .

[0033] (7) As shown in laminating process 14, the conveying table 9 of the retardation film F ₁ as a lower support member mounted support in a state of being inclined slightly downward by the contraction operation of the air cylinder 73 ,
The air cylinder 70 is extended to raise the movable table 72, and the air cylinder 83 is extended to extend the attaching roller 84.
The is raised, against the end of the polarizing plate F ₂ which is supported an end portion of the retardation film F ₁ to joining table 6 the lower surface.

[0034] Thereafter, sequentially pressed lamination is complete polarizing plate F ₂ over from one end to the other end of the phase difference film F ₁ by horizontally backward movement of the conveyor table 9 by driving the electric motor 74 I do.

[0035] Incidentally, while the laminating process in the lower joining table 6 as described above is being performed, the protective film peeling process of the polarizing plate F ₂ which are then processed by the upper joining table 6, and, Positioning processing is performed. Also,
In parallel with this, the separation table 5 of the retardation film F ₁
, A protective film peeling process, and a positioning process are performed.

(8) Composite Film Unloading Process When the laminating process is completed as described above, the transport mechanism 11 with the vacuum suction pad 11a facing upward enters the lower portion of the laminating table 6 by horizontal swing around the fulcrum h. Then, the bonded composite film is received, and then the vacuum suction pad 11a is turned over so that the vacuum suction pad 11a faces downward, and is horizontally oscillated to transfer the composite film onto the carry-out conveyor 10 and carry it out of the apparatus.

[Other Embodiments] The two kinds of films to be bonded are not limited to a retardation film and a polarizing plate, but can be applied to, for example, a case where a polarizing plate is bonded to a liquid crystal plate at a predetermined angle. Things. Moreover, it can also be implemented by forming an adhesive surface on the bonding surface of both films. Furthermore, the automatic film laminating apparatus described in the embodiments is an example to which the method of the present invention can be applied, and it goes without saying that the configuration of each unit of the apparatus can be variously changed.

[0038]

As is clear from the above description, in the method of the present invention, the lower first film is stuck to the other end while pressing the lower first film from one end to the upper second film in a free state. Therefore, no force is required to separate the first film from the lower support member, and the first film can be properly bonded to the second film with almost no unnecessary stress applied to the first film.

[Brief description of the drawings]

FIG. 1 is an overall plan view of an automatic film laminating apparatus to which the method of the present invention is applied.

FIG. 2 is a plan view of a first film storage unit and a first film transport mechanism.

FIG. 3 is a front view of a first film storage unit and a first film transport mechanism.

FIG. 4 is a plan view of a peeling table.

FIG. 5 is a front view of a peeling table.

FIG. 6 is an explanatory diagram sequentially showing a film transfer operation on a peeling table.

FIG. 7 is a front view of a first protective film peeling mechanism.

FIG. 8 is a plan view of a first protective film peeling mechanism.

FIG. 9 is a side view showing a part of the first protective film peeling mechanism.

FIG. 10 is a perspective view showing a peeling head of the first protective film peeling mechanism.

FIG. 11 (a) is a front view showing a protective film peeling start state. (B) It is an enlarged view of the principal part.

FIG. 12 is a plan view of a transfer table.

FIG. 13 is a front view of the transport table.

FIG. 14 is a front view of a main part showing a bonding start state.

[Explanation of symbols]

6 the upper support member (joining table) 9 lower support member (carrier table) 84 joining roller F ₁ phase difference film (first film) F ₂ polarizing plate (second film)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI // B29L 7:00 B29L 7:00 9:00 9:00 11:00 11:00 (58) Investigated field (Int.Cl. . ^7, DB name) B29C 65/00 - 65/82 B65H 37/04 G09F 9/00 342

Claims (1)

(57) [Claims] 1. A method of bonding a first film having a pressure-sensitive adhesive layer formed on at least one bonding surface and a second film, wherein the first film is placed on an upper surface of a lower support member, and The film is sucked and held on the lower surface of the upper support member, and one end of the first film on the lower support member is pressed against one end of the upper second film by a sticking roller, and in this state, the lower support member is placed on the lower surface of the upper support member. A film laminating method, wherein the first film is laminated to the second film by moving along the first film and the second film.