JP4342851B2 - Polarizing plate bonding method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polarizing plate bonding method and apparatus for bonding a polarizing plate to a substrate.
[0002]
[Prior art]
With the widespread use of liquid crystal display devices (hereinafter referred to as LCDs), the demand for polarizing plates is rapidly increasing. In the polarizing film, a protective film is generally bonded to both surfaces or one surface of a polarizing layer having polarizing ability (see FIG. 7B). As a material for the polarizing layer, polyvinyl alcohol (hereinafter referred to as PVA) is mainly used. After the PVA film is uniaxially stretched, it is dyed with iodine or a dichroic dye or dyed, and then stretched. A polarizing film for a polarizing layer is formed by crosslinking with a compound. As the protective film, cellulose triacetate (hereinafter referred to as TAC) is mainly used because it is optically transparent and has a small birefringence. Since the polarizing plate is usually stretched in the longitudinal direction, the absorption axis of the polarizing film is substantially parallel to the longitudinal direction (see FIG. 7A). The polarizing plate film is provided with an adhesive layer for bonding onto the substrate, and a release film for protecting the adhesive layer from foreign matters such as dust is bonded thereon. The polarizing film to which the release film is bonded is supplied in the form of a roll of a strip-like film stretched in the longitudinal direction.
[0003]
In an LCD using conventional TN (Twisted Nematic) liquid crystal, the transmission axis of the polarizing plate is inclined by 45 ° with respect to the vertical or horizontal direction of the screen. For this reason, a method (for example, Japanese Patent Application Laid-Open No. 2002-23151) for laminating pieces of polarizing plates in which roll-shaped polarizing plates are punched in advance in the direction of 45 ° with respect to the longitudinal direction of the roll, A method of cutting the polarizing plate after laminating the polarizing plate with the vertical or horizontal direction of the LCD screen inclined by 45 ° with respect to the roll longitudinal direction (see, for example, JP-A-11-95028, FIG. 7A). Has been devised. Also, in LCDs using VA (Vertical Alignment) liquid crystal and IPS (In Plane Switching) type liquid crystal, the transmission axis of the polarizing plate is arranged in the vertical or horizontal direction of the screen, Each sheet is attached to the LCD.
[0004]
[Patent Document 1]
JP 2002-23151 A [Patent Document 2]
Japanese Patent Laid-Open No. 11-95028
[Problems to be solved by the invention]
However, in the case of the method of bonding the polarizing plate pieces to the LCD one by one, when the polarizing plate pieces are bonded to the substrate, each polarizing plate piece is transferred and peeled off immediately before the bonding. Since it is necessary to peel off the film, there is a limit to shortening the process time. Moreover, since the polarizing plate piece is usually punched from a polarizing plate film in a roll form, curling easily occurs, and workability when transferring and transporting the polarizing plate piece is poor.
[0006]
Further, in the method of cutting the polarizing plate after laminating the polarizing plate by tilting the vertical or horizontal direction of the LCD screen by 45 ° with respect to the longitudinal direction of the roll, there are many unusable portions near the end of the roll. In particular, when a large-size polarizing plate is used with an increase in the screen size of the LCD, there is a problem that the yield is reduced. Moreover, since the piece of the polarizing plate which was not used for pasting is used in combination with a plurality of materials, it is difficult to reuse, resulting in an increase in waste. Such a problem is a problem common to the method of laminating the polarizing plate pieces one by one on the LCD.
[0007]
By the way, for the purpose of optical compensation such as coloring prevention and widening of the viewing angle, the retardation film is used by being adhered to a polarizing plate or the like forming an LCD, and the alignment axis is set at various angles with respect to the transmission axis of the polarizing plate. It is required to set. Conventionally, from a vertically or laterally uniaxially stretched film (for example, PET), a method is used in which the periphery is punched and cut so that the orientation axis has a predetermined inclination angle with respect to the side. A decrease in yield has been a problem.
[0008]
In addition, a thick composite film like a film in which a retardation film and a polarizing plate are bonded together is likely to produce cutting waste during cutting, and is cut when the composite film is cut immediately before the substrate and the composite film are bonded. In some cases, debris enters between the substrate and the composite film.
[0009]
Furthermore, the roll-type polarizing film has become larger and heavier as the display screen becomes larger, making it difficult to replace the roll.
[0010]
The first object of the present invention is to provide a polarizing plate laminating method and apparatus with high work efficiency and high polarizing plate yield.
[0011]
The second object of the present invention is to provide a polarizing plate laminating method and apparatus having a high yield of a composite film obtained by laminating a retardation film and a polarizing plate.
[0012]
The third object of the present invention is to provide a polarizing plate laminating method and apparatus in which cutting waste hardly enters between the substrate and the film even if the film is cut just before laminating.
[0013]
The fourth object of the present invention is to provide a polarizing plate laminating method and apparatus in which rolls can be easily replaced.
[0014]
[Means for Solving the Problems]
In the 1st viewpoint of this invention, it is a polarizing plate bonding apparatus which bonds a polarizing plate to a board | substrate, Comprising: A peeling film is bonded via an adhesive layer on a polarizing plate, and the board | substrate conveyed The peeling film separating means for separating the peeling film from the belt-like film supplied from one side of the plate surface, the adhesive surface of the belt-like film from which the peeling film is separated, and the traveling direction of the belt-like film is the direction of the substrate Bonding means for bonding to the corresponding plate surface of the substrate so as to correspond to the conveyance direction, and the belt-like film bonded to one side of the substrate by the bonding means on the front side in the conveyance direction of the substrate Cutting means that cuts in parallel with the end face of the film or the end face on the rear side thereof, and the cutting means cuts simultaneously from the vertical direction with respect to the surface of the strip-like film bonded to the substrate and Has two blades for cutting in the direction perpendicular to the conveying direction of the plate, the two blades are spaced at predetermined intervals, the front side of the first substrate in the conveying direction, and a second substrate on the rear side in the transport direction The band-like film in a state of being bonded to both the substrates is simultaneously cut on the first substrate and the second substrate using the two blades, and the first substrate and the second substrate are The opposite end faces are in contact with each other .
[0015]
In the 2nd viewpoint of this invention, it is a polarizing plate bonding method which bonds a polarizing plate to a board | substrate, Comprising: A peeling film is stuck on a polarizing plate through an adhesive bond layer, and the board | substrate conveyed A step of separating the release film from the belt-like film supplied from one side of the plate surface, an adhesive surface of the belt-like film from which the release film is separated, and a traveling direction of the belt-like film is a transport direction of the substrate In order to correspond, the process of bonding to the corresponding plate surface of the substrate, and the band-shaped film bonded to one surface of the substrate by the bonding, the front end surface or the rear side of the substrate in the transport direction Cutting in parallel with the end face of the substrate, and in the cutting step, the substrate is bonded to both the first substrate on the front side in the transport direction and the second substrate on the rear side in the transport direction. The strip film See write off simultaneously from a direction perpendicular to the surface of the filmstrip by the first substrate and the second substrate using two blades, wherein the first substrate and the second substrate, opposed end faces to each other Are in contact with each other.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1: is the side view and top view which showed typically the structure of the polarizing plate bonding apparatus which concerns on Embodiment 1 of this invention. FIG. 2: is the top view and sectional drawing which showed the structure of the strip | belt-shaped film used in the polarizing plate bonding apparatus which concerns on Embodiment 1 of this invention. FIG. 3 is a side view schematically showing the operation of the cutting means of the polarizing plate bonding apparatus according to Embodiment 1 of the present invention.
[0017]
Referring to FIG. 1, a polarizing plate laminating apparatus 20 for laminating a polarizing plate (film piece 19) on a substrate 1, and a release film 11 is stuck on a polarizing plate via an adhesive layer, Release film separating means 21 for separating the release film 11 from the strip film 10 supplied from one side of the plate surface of the substrate 1 to be conveyed, and an adhesive surface of the strip film 10 from which the release film 11 has been separated, A bonding means 22 for bonding to a corresponding plate surface of the substrate 1 and a single surface of the substrate 1 by the bonding means 22 so that the traveling direction of the strip film 10 corresponds to the transport direction of the substrate 1. And a cutting means 23 for cutting the bonded strip-like film 10 in parallel with the end face on the front side in the transport direction of the substrate 1 or the end face on the rear side thereof, thereby allowing the polarizing film piece to be continuously formed. It can be automatically stuck, thereby reducing waste.
[0018]
The belt-like film 10 applied in the present invention is a film using a polarizing plate to which a release film 11 is attached via an adhesive layer. For example, as shown in FIG. A circularly polarizing film to which the retardation film 13 is bonded may be used. When the polarizing plate 16 is used for an LCD for a TN liquid crystal, the transmission axis direction is obliquely oriented with respect to the film longitudinal direction, and the inclination angle between the film longitudinal direction and the transmission axis direction is 20 ° or more and 70 °. Although it is preferably below, it is more preferably 40 ° or more and 50 ° or less, and usually 45 ° (see FIG. 2 (A)). For a method for producing such a polarizing plate, refer to JP-A-2002-86554. The polarizing plate 16 preferably has protective films 15 and 17 attached to both sides thereof. Since the polarizing plate 16 here is a polarizing plate that is obliquely stretched with respect to the longitudinal direction of the film, it is hereinafter referred to as an “obliquely stretching polarizing plate”. If the obliquely stretched polarizing plate 16 is used, a continuous film can be supplied. In the case of a circularly polarizing film in which the retardation film 13 is bonded to the obliquely stretched polarizing plate 16 (protective film 15) via the adhesive layer 14, the retardation film 13 has an orientation axis orthogonal or parallel to the film longitudinal direction. It is preferable to use what has. If it does in this way, a circularly-polarizing film can be supplied continuously. The thickness of the polarizing plate 16 is, for example, about 5 to 100 μm. The width of the polarizing plate 16 is appropriately selected according to the size of the substrates to be bonded. The adhesives 12 and 14 may be ordinary adhesives (for example, acrylic adhesives, polyurethane adhesives, epoxy adhesives, rubber adhesives, etc.) used for bonding the substrate and the optical film. . The release film 11 is a release material and may be an ordinary release material (for example, a polyethylene terephthalate film, a polyester film, etc.) used for an optical film. In order to protect the surface of the film from scratches or the like, an interleaf paper 18 may be attached to the surface of the polarizing plate 16 facing the surface on which the release film 11 is attached. The strip film 10 is preferably supplied from an unwinding roll 24 (see FIG. 1). In addition, when using for LCD for VA liquid crystal or LCD for IPS system liquid crystal, the polarizing plate 16 can be used in which the transmission axis direction is parallel or perpendicular to the film longitudinal direction.
[0019]
The substrate 1 is a flat plate member such as a glass substrate or a synthetic resin substrate used for a display device such as a liquid crystal display device or a plasma display device, and may be a substrate on which components such as a liquid crystal cell and an electrode are formed in advance. Good. The shape of the substrate 1 is preferably a substantially square shape such as a square or a rectangle (see FIGS. 1 and 2A).
[0020]
The release film separating means 21 is a means for separating the release film 11 from the belt-like film 10, and examples thereof include a roller and a wedge member. The release film 11 separated from the belt-like film 10 by the release film separating means 21 may be wound around a take-up roll 25 and recovered (see FIG. 1).
[0021]
The bonding means 22 is a means for bonding the adhesive surface of the band-shaped film 10 from which the release film 11 has been separated to a corresponding position on the substrate 1 so that the traveling direction of the band-shaped film 10 corresponds to the transport direction of the substrate 1. Yes (see FIG. 1), for example, a nip roller that presses from both sides of the substrate.
[0022]
The cutting means 23 is a push-cut type cutter, a dicing type cutter, or the like used for cutting an optical film. For example, a cutter blade, a cylinder that drives the cutter blade, a bottom dead center position adjustment that adjusts a bottom dead center position of the cutter blade. The thing provided with a member is mentioned (refer FIG. 1). By adjusting the bottom dead center position to 0 to 0.5 times the thickness of the release film 11, only the belt-like film 10 is cut in a direction perpendicular to the film longitudinal direction (not half cut but complete cut) (See FIG. 1). In FIG. 1, the belt-like film 10 is cut once from the upper side of the contact portion between the substrate 1 and the substrate 1 adjacent thereto, but when so-called frame pasting is performed (a predetermined distance from the end of the substrate 1). When the film piece 19 is pasted with a gap between the contact portions, the cutting is performed twice before and after the contact portion (first cutting on one substrate 1 and second cutting on the adjacent substrate 1). ) May be performed. When the frame is pasted, unnecessary cut pieces (strips) will come out. Moreover, when the strip | belt-shaped film 10 is continuously bonded to a board | substrate, without stopping conveyance of a board | substrate, the cutting | disconnection means 23 makes it respond | correspond to the conveyance speed and its direction of the said board | substrate on the said conveyance means in a one part area. (See FIG. 3). The movement of the cutting means 23 in this case includes movements such as D1 to D4 in FIG. 3 when viewed from the side, and at least the movement speed of D1 is the same as the conveyance speed of the substrates 1A and 1B. During the movement, the cutting means 23 is lowered to the substrate side, and the strip film 10 is cut from the upper side of the contact portion between the substrate 1A and the substrate 1B. The movement of the cutting means 23 may rotate when viewed from the side.
[0023]
The transport means 26 is a means for transporting the substrate 1 in the direction of the bonding means 22 or its extending direction with one end face of the substrate 1 orthogonal to the traveling direction, and is horizontally disposed on a plurality of arranged rollers or wheels. 1 is preferably a roller conveyor or a wheel conveyor, but more preferably a roller outer cylinder or wheel is attached to a rotating shaft via a bearing so that the surface matches the speed of the substrate being transferred. It is preferable to prevent generation of scratches on the substrate caused by the roller outer cylinder or wheel rotating at a speed and sliding between the roller outer cylinder or wheel and the substrate. The transport means 26 transports a plurality of substrates 1 having a substantially square shape and a constant size arranged in series in the traveling direction on the substrate, and the substrate film 10 is bonded to the substrate 1 by the bonding means 22. It is preferable that the front end surfaces and the rear end surfaces in one transport direction are brought into contact with the front or rear end surfaces in the transport direction of adjacent substrates 1 for transport.
[0024]
Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 4: is the side view and top view which showed typically the structure of the polarizing plate bonding apparatus which concerns on Embodiment 2 of this invention. FIG. 5: is the side view which showed typically operation | movement of the cutting | disconnection means of the polarizing plate bonding apparatus which concerns on Embodiment 2 of this invention.
[0025]
The polarizing plate bonding apparatus 30 according to the second embodiment is substantially the same as the configuration of the polarizing plate bonding apparatus according to the first embodiment except for the cutting means 33A and 33B.
[0026]
The cutting means 33A and 33B are means for cutting the strip-like film 10 bonded to one side of the substrate 1 by the bonding means 32 in parallel with the front end surface in the transport direction of the substrate 1 or the end surface on the rear side thereof. In the case of so-called frame pasting in which the film piece 19 is pasted at a predetermined interval from the end of the substrate 1, the substrate 1 is simultaneously cut from the vertical direction with respect to the surface of the strip film 10 pasted on the substrate 1. It is preferable to have two blades 33A and 33B that cut in a direction orthogonal to one transport direction, and the two blades 33A and 33B are separated from each other at a predetermined interval (see FIG. 4). The two blades 33A and 33B cut the strip film 10 on the plate surfaces of different substrates 1A and 1B, respectively (see FIG. 5). In this case, it is preferable to have a suction means 37 for sucking an unnecessary cut piece 2 (strip) of the cut strip-shaped film 10 between the two blades 33A and 33B. The suction means 37 operates together with the two blades 33A and 33B. Even in such a case, the two blades 33A and 33B may operate in accordance with the transport speed and direction of the substrate 1 on the transport unit 36 in a part of the section. When performing such cutting, as shown in FIG. 5, the front and rear end surfaces in the transport direction of the substrate 1A are brought into contact with the front or rear end surfaces in the transport direction of the adjacent substrates 1B. It is preferable to contact. It is because the cut piece 2 can be made small and the yield of a polarizing plate can be raised by bonding the strip | belt-shaped film 10 in the state which the board | substrates 1 contact | abutted.
[0027]
Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 6: is the side view which showed typically the structure of the polarizing plate bonding apparatus which concerns on Embodiment 3 of this invention.
[0028]
The polarizing plate bonding apparatus 40 according to the third embodiment is substantially the same as the configuration of the polarizing plate bonding apparatus according to the first embodiment except for the arrangement positions of the release film separating means 41, the unwinding roll 44, and the winding roll 45. is there. The polarizing plate bonding apparatus 40 includes a release film separating unit 41, an unwinding roll 44, and a winding roll 45 below the substrate 1 that is transported on the transporting unit 46. By supplying and laminating the belt-like film 10 from the lower side of the surface of the substrate 1 to be conveyed, dust can be prevented from being mixed, and the roll of the belt-like film can be easily exchanged.
[0029]
【The invention's effect】
According to this invention, since it can bond, without stopping conveyance of a board | substrate and supply of a film, productivity improves.
[0030]
Moreover, according to this invention, since there is no need of transfer of a film piece and the peeling film is not cut | disconnected, it can bond at high speed.
[0031]
In addition, according to the present invention, it is possible to prevent the unnecessary polarizing piece from being cut out, and therefore the yield of the polarizing plate can be set to 100% unless so-called frame attachment.
[0032]
In addition, according to the present invention, the circularly polarizing plate film obtained by laminating the retardation film and the polarizing plate can be continuously pasted to the substrate, so that unnecessary cut pieces of the circularly polarizing plate film do not come out. Therefore, the yield of the circularly polarizing plate film can be set to 100% unless so-called frame attachment.
[0033]
Further, according to the present invention, when the film piece is supplied from the lower side of the substrate to be transported, it is possible to prevent dust from being mixed due to falling of dust attached to the polarizing plate.
[0034]
Furthermore, according to this invention, when supplying a strip | belt film from the downward side of the board | substrate conveyed, replacement | exchange of the roll of a strip | belt-shaped film is easy.
[Brief description of the drawings]
1A and 1B are a side view and a plan view schematically showing the configuration of a polarizing plate bonding apparatus according to Embodiment 1 of the present invention.
FIGS. 2A and 2B are a plan view and a cross-sectional view showing the configuration of a strip film used in the polarizing plate laminating apparatus according to Embodiment 1 of the present invention. FIGS.
FIG. 3 is a side view schematically showing the operation of the cutting means of the polarizing plate bonding apparatus according to Embodiment 1 of the present invention.
FIGS. 4A and 4B are a side view and a plan view schematically showing the configuration of a polarizing plate bonding apparatus according to Embodiment 2 of the present invention. FIGS.
FIG. 5 is a side view schematically showing the operation of the cutting means of the polarizing plate bonding apparatus according to Embodiment 2 of the present invention.
FIG. 6 is a side view schematically showing a configuration of a polarizing plate bonding apparatus according to Embodiment 3 of the present invention.
FIGS. 7A and 7B are a plan view and a cross-sectional view showing a configuration of a strip film used in a conventional polarizing plate laminating apparatus. FIGS.
[Explanation of symbols]
1 Substrate 2 Cut piece (band)
DESCRIPTION OF SYMBOLS 10 Band-shaped film 11 Release film 12, 14 Adhesive layer 13 Retardation film 15, 17 Protective film 16 Polarizing plate 18 Interleaf paper 19 Film piece 20, 30, 40 Polarizing plate bonding apparatus 21, 31, 41 Release film separation means 22 , 32, 42 Pasting means 23, 33A, 33B, 43 Cutting means 24, 34, 44 Unwinding rolls 25, 35, 45 Winding rolls 26, 36, 46 Conveying means 37 Suction means

Claims (13)

A release film is attached to the polarizing plate via an adhesive layer, and a release film separating means for separating the release film from the belt-like film supplied from one side of the plate surface of the substrate to be conveyed,
Bonding means for bonding the adhesive surface of the strip-shaped film from which the release film has been separated, to the corresponding plate surface of the substrate, so that the traveling direction of the strip-shaped film corresponds to the transport direction of the substrate;
Cutting means for cutting the strip-like film bonded to one side of the substrate by the bonding means in parallel with the front end surface in the transport direction of the substrate or the rear end surface thereof;
With
The cutting means has two blades that simultaneously cut from the vertical direction with respect to the surface of the band-shaped film bonded to the substrate and cut in a direction orthogonal to the transport direction of the substrate, the two blades being predetermined The band-like film in a state of being bonded to both the first substrate on the front side in the transport direction and the second substrate on the rear side in the transport direction , spaced apart from each other using the two blades. Cutting simultaneously on the first substrate and the second substrate,
The polarizing plate laminating apparatus, wherein the first substrate and the second substrate are in contact with each other at opposite end surfaces .   The polarizing plate laminating apparatus according to claim 1, further comprising a conveying unit that conveys the substrate toward the laminating unit or in an extending direction thereof with one end face of the substrate orthogonal to the traveling direction.   The polarizing plate bonding apparatus according to claim 2, wherein the conveying means is a roller conveyor in which rollers are arranged or a wheel conveyor in which wheels are arranged. Using a substantially square and constant size substrate,
The polarizing plate bonding apparatus according to claim 2 or 3, wherein the transport means transports the plurality of substrates arranged in series in a traveling direction.   The polarizing plate bonding apparatus according to claim 1, wherein the cutting unit includes a suction unit that is disposed between the two blades and sucks unnecessary cut pieces of the cut strip-shaped film.   The polarizing plate laminating apparatus according to any one of claims 2 to 5, wherein the cutting means operates in accordance with the conveyance speed and direction of the substrate on the conveyance means in a part of the section. .   When the belt-like film is bonded to the substrate by the bonding means, the transfer means has a front side or a rear side in the transfer direction of the substrates adjacent to each other on the front and rear end surfaces in the transfer direction of the substrate. The polarizing plate laminating apparatus according to claim 2, wherein the polarizing plate laminating apparatus is conveyed while being in contact with an end face on the side. The transport means transports the substrate surface substantially horizontally,
The release film separating means is disposed below the substrate conveyed by the conveying means,
The polarizing plate according to any one of claims 1 to 7, wherein the bonding unit bonds the belt-like film supplied from the lower side of the substrate conveyed by the conveying unit to the substrate. Bonding device.   9. The retardation film having an alignment axis perpendicular or parallel to the film longitudinal direction is interposed between the polarizing plate and the adhesive layer in the belt-shaped film. The polarizing plate bonding apparatus as described in.   The polarizing plate bonding apparatus according to any one of claims 1 to 9, wherein a polarizing plate having a transmission axis obliquely oriented with respect to the film longitudinal direction is used as the polarizing plate.   The polarizing plate bonding apparatus according to any one of claims 1 to 9, wherein a polarizing plate having a transmission axis oriented parallel to the longitudinal direction of the film is used as the polarizing plate.   The polarizing plate bonding apparatus according to any one of claims 1 to 9, wherein a polarizing plate having a transmission axis oriented at right angles to the longitudinal direction of the film is used as the polarizing plate. A step of separating the release film from the belt-like film supplied from one side of the plate surface of the substrate to be transported, while the release film is stuck on the polarizing plate via an adhesive layer;
Bonding the adhesive surface of the strip-like film from which the release film has been separated, to the corresponding plate surface of the substrate such that the traveling direction of the strip-shaped film corresponds to the transport direction of the substrate;
Cutting the strip-like film bonded to one side of the substrate by the bonding in parallel with the end surface on the front side in the transport direction of the substrate or the end surface on the rear side;
Including
In the step of cutting, the belt-like film in a state of being bonded to both the first substrate on the front side in the transport direction and the second substrate on the rear side in the transport direction using the two blades. see write off simultaneously from a direction perpendicular to the surface of the filmstrip at the first substrate and the second substrate,
The polarizing plate laminating method, wherein the first substrate and the second substrate are in contact with each other at opposite end surfaces .

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