TW202413035A - Manufacturing method of polarizing plate with phase difference layer - Google Patents

Abstract

The present invention provides a method for efficiently manufacturing a polarizing plate with a phase difference layer, wherein the absorption axis direction of the polarizer and the slow axis direction of the phase difference layer of the polarizing plate with a phase difference layer are extremely precisely controlled. The manufacturing method of the polarizing plate with a phase difference layer of the embodiment of the present invention comprises the following steps: a blank roll of a phase difference film having a slow axis in the long direction is punched into a predetermined size while correcting the offset of the slow axis in the width direction of the blank roll relative to the long direction, thereby obtaining a single-piece phase difference layer intermediate having a slow axis in the long direction; a blank roll of a polarizing plate having an absorption axis in the long direction is punched into the same size as the phase difference layer intermediate, A single polarizing plate intermediate having an absorption axis at 45° relative to the long side direction is obtained; a phase difference layer intermediate is bonded to a polarizing plate intermediate in such a way that the outer edges thereof are aligned, thereby obtaining a polarizing plate intermediate with a phase difference layer, wherein the angle between the absorption axis of the polarizing plate and the slow axis of the phase difference layer is 45°; and, the polarizing plate intermediate with a phase difference layer is punched to obtain a polarizing plate sheet with a phase difference layer of a predetermined size having an absorption axis in the long side direction.

Description

Manufacturing method of polarizing plate with phase difference layer

The present invention relates to a method for manufacturing a polarizing plate with a phase difference layer.

Image display devices represented by liquid crystal display devices and electroluminescent (EL) display devices (such as organic EL display devices and inorganic EL display devices) are rapidly becoming popular. In order to realize image display and/or improve the performance of the image display, polarizing plates with phase difference layers, which include polarizing plates and phase difference films (phase difference layers), are widely used in image display devices. In addition, in recent years, new uses of image display devices are being developed. One example of such uses is virtual reality (VR) goggles. When polarizing plates with phase difference layers are applied to VR goggles, their size is significantly smaller than that of conventional uses. As a result, the axial offset of the absorption axis of the polarizer and/or the slow axis of the phase difference layer, which is not a problem in conventional uses, becomes a substantial problem. Prior art literature Patent literature

Patent document 1: Japanese Patent Publication No. 2013-182162

Problem to be solved by the invention This invention is made to solve the above-mentioned problem. Its main purpose is to provide a method for efficiently manufacturing a polarizing plate with a phase difference layer, in which the absorption axis direction of the polarizer and the slow axis direction of the phase difference layer are extremely precisely controlled.

Means for solving the problem The manufacturing method of the polarizing plate with phase difference layer in the embodiment of the present invention comprises the following steps: a blank roll of phase difference film having a slow axis in the longitudinal direction is punched into a predetermined size while correcting the deviation of the slow axis in the width direction of the blank roll relative to the longitudinal direction, thereby obtaining a single phase difference layer intermediate having a slow axis in the longitudinal direction; a blank roll of polarizing plate having an absorption axis in the longitudinal direction is punched into the same size as the phase difference layer intermediate, thereby obtaining a single phase difference layer intermediate having an absorption axis in a direction at 45° relative to the longitudinal direction. a polarizing plate intermediate; laminating the phase difference layer intermediate and the polarizing plate intermediate in such a way that the outer edges thereof are aligned, thereby obtaining a polarizing plate intermediate with a phase difference layer, wherein the angle between the absorption axis of the polarizing plate and the slow axis of the phase difference layer is 45°; and punching the polarizing plate intermediate with a phase difference layer, thereby obtaining a polarizing plate sheet with a phase difference layer having a predetermined size of absorption axis in the long side direction. In one embodiment, the manufacturing method obtains 3 to 16 phase difference layer intermediates in the width direction from the blank roll of the phase difference film. In one embodiment, the phase difference layer intermediate and the polarizing plate intermediate are rectangular with a short side of 75 mm to 310 mm. In one embodiment, the polarizing plate with phase difference layer is a rectangle with a long side of 10mm~70mm and a short side of 10mm~70mm.

Effect of the invention According to the implementation form of the present invention, a method for efficiently manufacturing a polarizing plate with a phase difference layer can be realized, wherein the absorption axis direction of the polarizer and the slow axis direction of the phase difference layer of the polarizing plate with a phase difference layer are extremely precisely controlled.

Hereinafter, the embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments. In addition, the drawings are schematic representations and do not accurately depict actual conditions.

A. Overview of the manufacturing method of the polarizing plate with phase difference layer The manufacturing method of the polarizing plate with phase difference layer of the embodiment of the present invention comprises the following steps: a blank roll of a phase difference film having a slow axis in the longitudinal direction is punched into a predetermined size while correcting the deviation of the slow axis in the width direction of the blank roll relative to the longitudinal direction to obtain a single-piece phase difference layer intermediate having a slow axis in the longitudinal direction (for convenience, referred to as the phase difference layer intermediate manufacturing step); a blank roll of a polarizing plate having an absorption axis in the longitudinal direction is punched into the same size as the phase difference layer intermediate to obtain a single-piece phase difference layer intermediate having a slow axis in the longitudinal direction at a 45° angle relative to the longitudinal direction. A single polarizing plate intermediate with an absorption axis (for convenience, referred to as a polarizing plate intermediate manufacturing step); the phase difference layer intermediate and the polarizing plate intermediate are bonded together in such a way that the outer edges thereof are aligned, thereby obtaining a polarizing plate intermediate with a phase difference layer whose absorption axis of the polarizing plate and the slow axis of the phase difference layer form an angle of 45° (for convenience, referred to as a polarizing plate intermediate with a phase difference layer manufacturing step); and, the polarizing plate intermediate with a phase difference layer is punched to obtain a polarizing plate sheet with a phase difference layer of a predetermined size having an absorption axis in the long side direction (for convenience, referred to as a final step). Each step is described in detail below. In addition, the description of "absorption axis of polarizing plate" in this manual refers to the absorption axis of the polarizer contained in the polarizing plate.

B. Phase difference layer intermediate production steps Figure 1(a) and Figure 1(b) are schematic diagrams illustrating the phase difference layer intermediate production steps. First, as shown in Figure 1(a), a phase difference film stock roll is prepared. The phase difference film is typically a stretched film of a resin film having a slow axis in the long strip direction of the roll. Representative examples of resins constituting phase difference films include: polycarbonate resins, polyester carbonate resins, polyester resins, polyvinyl acetal resins, polyarylate resins, cyclic olefin resins, cellulose resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, acrylic resins, etc.

The optical properties of the phase difference film can be appropriately set according to the purpose. The phase difference film has a slow axis, and shows the relationship of nx>ny. The phase difference film typically shows the refractive index characteristics of nx>ny≧nz. The phase difference film can typically function as a λ/4 plate. The in-plane phase difference Re(550) of the phase difference film is preferably 100nm~200nm, more preferably 110nm~180nm, and more preferably 130nm~150nm. Because the phase difference film functions as a λ/4 plate, the phase difference film and the polarizer (polarizer) are layered in such a way that the slow axis of the phase difference film and the absorption axis of the polarizer are typically at an angle of 45°, thereby obtaining a polarizer (circular polarizer) with a phase difference layer having excellent anti-reflection function. Here, "Re(λ)" is the in-plane phase difference measured at 23°C with light of wavelength λnm. Therefore, "Re(550)" is the in-plane phase difference measured at 23°C with light of wavelength 550nm. Re(λ) is calculated by the formula: Re(λ)=(nx-ny)×d when the thickness of the layer (film) is set to d(nm).

The phase difference film can show the reverse dispersion wavelength characteristic that the phase difference value increases with the wavelength of the measured light, the positive wavelength dispersion characteristic that the phase difference value decreases with the wavelength of the measured light, and the flat wavelength dispersion characteristic that the phase difference value hardly changes with the wavelength of the measured light.

The thickness of the phase difference film can be set to be able to optimally function as a λ/4 plate. In other words, the thickness can be set to obtain the above-mentioned desired in-plane phase difference. Specifically, the thickness is preferably less than 70 μm, preferably 15 μm to 60 μm.

As shown in FIG1(a), the phase difference film typically has an axial offset in the width direction in the stock roll 10. In more detail, the direction of the slow axis S of the phase difference film is offset by a predetermined angle relative to the long direction of the roll at the end of the width direction of the roll. The axial offset is typically not substantially apparent in the central portion, and becomes larger as it approaches the end in the width direction. The axial offset at the end in the width direction may vary with the width of the roll. For example, in a roll with a width of about 1000 mm to 1500 mm, the axial offset at the end in the width direction may be, for example, 1° to 3°. When manufacturing large-scale (e.g., TV-use) polarizing plates with phase difference layers, the axial offset does not substantially become a problem. This is because by improving the color unevenness or viewing angle dependence of the polarizing plate with a phase difference layer as a whole, the problem of axial offset will not surface or become serious. On the other hand, the inventors of the present invention have newly discovered that when manufacturing a very small polarizing plate with a phase difference layer (for example, for VR goggles: a size of about 20mm×30mm), the characteristics of each final product will vary greatly to an unacceptable degree due to the axial offset. In addition, the inventors of the present invention have repeatedly corrected errors in order to solve this problem and found that the axial offset of the slow axis of the phase difference film has a greater impact on the problem than the axial offset of the absorption axis of the polarizer. The problem can be solved by adopting a process that can appropriately eliminate the axial offset of the slow axis of the phase difference film, thereby completing the present invention. That is, the embodiments of the present invention can solve new problems that have not been recognized so far, and the effects thereof are unexpectedly excellent.

In the embodiment of the present invention, as shown in FIG1(a), the offset of the slow axis S in the width direction of the blank coil 10 relative to the longitudinal direction is corrected while the blank coil 10 is punched into a predetermined size, thereby obtaining a single-piece (rectangular in representation) phase difference layer intermediate 12 having a slow axis S in the longitudinal direction as shown in FIG1(b). More details are as follows. First, the axial offset of the slow axis S in the blank coil 10 is detected. As a method for detecting the axial offset, any appropriate means can be used. For example, the "AxoScan" manufactured by Axometrics can be used to measure the axial angle to detect the axial offset. When the axis offset is detected, the direction of the punching knife is adjusted according to the detected information, and then the punching knife with the adjusted direction is used to punch the predetermined position of the blank roll. The result is shown in Figure 1(b). Regardless of the punching position of the blank roll, a phase difference layer intermediate 12 with a slow axis S in the long side direction (i.e., the slow axis direction is precisely controlled) and very small (substantially no) variation in the slow axis direction of each intermediate can be obtained. When manufacturing the phase difference layer intermediate, the axial deviation of the slow axis in the stock roll is corrected, which substantially eliminates the variation of the slow axis direction of each intermediate in the phase difference layer intermediate. This makes the axial direction control during the manufacturing of the polarizing plate intermediate with phase difference layer and the polarizing plate sheet with phase difference layer (the polarizing plate with phase difference layer as the final product) described later become extremely simple and easy.

FIG. 1( a) shows an example of punching 3 phase difference layer intermediates from a stock roll in the width direction. However, in the embodiment of the present invention, for example, 3 to 16 or 5 to 6 phase difference layer intermediates can be punched from a stock roll in the width direction. If the above structure is adopted, a phase difference layer intermediate with excellent manufacturing efficiency, less waste of stock rolls, and properly corrected axial offset of the stock roll can be obtained. At this time, the obtained phase difference layer intermediate can be, for example, a rectangle with a short side of about 75 mm to 310 mm, or a rectangle with a long side of about 250 mm to 350 mm and a short side of about 150 mm to 250 mm.

Regarding the punching of the phase difference layer intermediate, the punching can be performed one by one while correcting the axis deviation; or the directions of a predetermined number of punching knives can be adjusted on one row in the width direction, and the punching can be performed in units of the one row.

C. Polarizing plate intermediate manufacturing step In addition, as shown in FIG. 2(a), a polarizing plate blank roll 20 is prepared. The polarizing plate generally has a polarizing element and a protective film disposed on at least one side of the polarizing element. As the polarizing element, any appropriate polarizing element can be used. The resin film forming the polarizing element can be a single-layer resin film, or a laminate of two or more layers can be used for manufacturing. Specific examples of polarizers composed of a single layer of resin film include: polyvinyl alcohol (PVA) resin film, partially formalized PVA resin film, ethylene-vinyl acetate copolymer partially saponified film and other hydrophilic polymer films dyed and stretched using dichroic substances such as iodine or dichroic dyes; polyene oriented films such as dehydrated PVA or dehydrogenated polyvinyl chloride. It is preferable to use a polarizer obtained by dyeing a PVA resin film with iodine and uniaxially stretching it because of its excellent optical properties. The dyeing with iodine is performed by, for example, immersing the PVA resin film in an iodine aqueous solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching can be performed after dyeing or while dyeing. In addition, it can be stretched before dyeing. If necessary, the PVA resin film can be subjected to swelling treatment, crosslinking treatment, cleaning treatment, drying treatment, etc. For example, by immersing the PVA resin film in water and washing it before dyeing, not only can the dirt or anti-adhesive agent on the surface of the PVA resin film be washed away, but the PVA resin film can also be swollen, thereby preventing uneven dyeing.

Specific examples of polarizers obtained using a laminate include a laminate using a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate using a resin substrate and a PVA-based resin layer coated on the resin substrate. A polarizer obtained by using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be produced, for example, by the following steps: a PVA-based resin solution is coated on the resin substrate and dried to form a PVA-based resin layer on the resin substrate, thereby obtaining a laminate of the resin substrate and the PVA-based resin layer; and the laminate is stretched and dyed to make the PVA-based resin layer into a polarizer. In this embodiment, stretching typically includes immersing the laminate in a boric acid aqueous solution for stretching. And if necessary, stretching can further include stretching the laminate in the air at a high temperature (e.g., above 95° C.) before stretching in the boric acid aqueous solution. The obtained resin substrate/polarizer laminate can be used directly (i.e., the resin substrate can be used as a protective layer of the polarizer), or the resin substrate can be peeled off from the resin substrate/polarizer laminate and any appropriate protective layer that meets the purpose can be used on the peeled off area layer. The details of the manufacturing method of the polarizer are described in, for example, Japanese Patent Publication No. 2012-73580 and Japanese Patent No. 6470455. The contents of these patent documents are cited in this specification as a reference.

The protective film is made of any appropriate film that can be used as a protective film for polarizers. Specific examples of the main component material of the film include: cellulose resins such as triacetate cellulose (TAC); or transparent resins such as polyester, polyvinyl alcohol, polycarbonate, polyamide, polyimide, polyether sulfone, polysulfone, polystyrene, polynorbornene, polyolefin, cyclic olefin, (meth)acrylic acid, and acetate. In addition, thermosetting resins or ultraviolet curing resins such as (meth)acrylic acid, urethane, (meth)acrylic urethane, epoxy, and polysilicone can also be listed. Other examples include glassy polymers such as siloxane polymers. In addition, the polymer film described in Japanese Patent Publication No. 2001-343529 (WO01/37007) can also be used. As the material of the film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted amide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain can be used, for example: a resin composition having an alternating copolymer composed of isobutylene and N-methyl cis-butylene diimide and an acrylonitrile-styrene copolymer. The polymer film can be, for example, an extruded product of the above resin composition. TAC, (meth) acrylic resin, and cyclic olefin resin can be used preferably.

As shown in FIG. 2( a ), the polarizing plate representative has substantially no axial offset in the width direction in the stock roll 20. In more detail, due to the material, optical properties, manufacturing method, etc., the direction of the absorption axis A of the polarizer appears to be substantially parallel to the long strip direction of the stock roll throughout the width direction of the stock roll. That is, the axial offset of the absorption axis of the polarizer in the width direction does not substantially exist, or even if it exists, it is very small relative to the axial offset of the slow axis of the phase difference film. Therefore, when making the polarizing plate intermediate 22 from the polarizing plate stock roll 20, it is not necessary to perform punching while correcting the axial offset. As a result, in the embodiment of the present invention, for example, by using a grid-shaped punching knife, as shown in FIG2(b), a plurality of polarizing plate intermediates can be punched out in batches. In the example shown in the figure, by punching out in a direction of 45° relative to the long strip direction of the blank roll, a single (representatively rectangular) polarizing plate intermediate 22 having an absorption axis A in a direction of 45° relative to the long side direction can be obtained as shown in FIG2(c). By punching out a plurality of polarizing plate intermediates in batches in this way, excellent manufacturing efficiency can be achieved. Furthermore, if the sheets are punched out one by one in an oblique direction (a direction at a predetermined angle relative to the long strip direction of the stock roll), even if there is no axial deviation in the stock roll, there will still be a situation where the axial direction of each punched intermediate varies. However, such a problem can be avoided by punching out in batches. That is, the polarizing plate intermediate 22 can be obtained, in which the absorption axis direction is precisely controlled and the variation of the absorption axis direction of each intermediate is very small (substantially no variation). In addition, those with ordinary knowledge in the art should understand that the punching angle (the angle relative to the long strip direction of the stock roll) can be set appropriately according to the purpose in addition to 45°. This angle is equivalent to the angle formed by the absorption axis of the polarizer in the polarizing plate with a phase difference layer and the slow axis of the phase difference layer.

The above-mentioned oblique punching can be performed in the following way: detect the edge of the blank coil in the width direction, adjust the direction of the punching knife according to the detected information, and then perform punching with the adjusted punching knife.

The size of the punched polarizing plate intermediate is typically the same as the size of the phase difference layer intermediate. Therefore, the obtained polarizing plate intermediate can be, for example, a rectangle with a short side of about 75mm to 310mm, or a rectangle with a long side of about 250mm to 350mm and a short side of about 150mm to 250mm. If it is the above structure, as described later, the preparation of the polarizing plate intermediate with a phase difference layer is simple and easy, and the angle control of the absorption axis of the polarizer and the slow axis of the phase difference layer (phase difference film) in the polarizing plate intermediate with a phase difference layer is easy.

D. Preparation steps of polarizing plate intermediate with phase difference layer Next, as shown in FIG3(a), the phase difference layer intermediate 12 obtained in the manner described in item B above and the polarizing plate intermediate 22 obtained in the manner described in item C above are bonded together to obtain the polarizing plate intermediate with phase difference layer. The phase difference layer intermediate and the polarizing plate intermediate are typically bonded together in such a manner that their outer edges are aligned. As mentioned above, the phase difference layer intermediate and the polarizing plate intermediate are both precisely controlled in the axial direction, and the variation in the axial direction of each intermediate is very small. Therefore, by laminating them in a way that their outer edges are consistent, the angle between the absorption axis of the polarizer and the slow axis of the phase difference layer in the polarizing plate intermediate with phase difference layer can be well controlled without precise and/or delicate operations. In addition, it goes without saying that the operation is simple and easy, so the preparation of the polarizing plate intermediate with phase difference layer is also simple and easy. In this way, a phase difference layer with a slow axis in the long side direction and an angle of 45° between the absorption axis of the polarizer and the slow axis of the phase difference layer can be obtained.

E. Final step Next, as shown in FIG3(b) and FIG3(c), the polarizing plate intermediate 30 with a phase difference layer obtained in the manner described in item D above is punched to obtain a polarizing plate sheet with a phase difference layer (a polarizing plate with a phase difference layer as a final product) 32. Punching is performed at a direction of 45° relative to the long side direction of the polarizing plate intermediate with a phase difference layer. As a result, as shown in FIG3(c), a polarizing plate sheet with a phase difference layer (a polarizing plate with a phase difference layer as a final product) can be obtained, in which the polarizer has an absorption axis in the long side direction and the angle between the absorption axis of the polarizer and the slow axis of the phase difference layer is 45°. As described above, in the polarizing plate intermediate with a phase difference layer, the angle between the absorption axis of the polarizer and the slow axis of the phase difference layer has been well controlled. Therefore, when the polarizing plate sheet 32 with a phase difference layer is produced from the polarizing plate intermediate with a phase difference layer 30, it is not necessary to perform punching while correcting the axis offset. As a result, in an embodiment of the present invention, for example, by using a grid-shaped punching knife, as shown in FIG. 3(b), a plurality of polarizing plate sheets with a phase difference layer can be punched out in batches. By punching out a plurality of polarizing plate sheets with a phase difference layer in this way, excellent manufacturing efficiency can be achieved. In addition, if the sheets are punched out one by one in an oblique direction (a direction at a predetermined angle relative to the long side direction of the polarizing plate intermediate with a phase difference layer), even if there is no axial offset in the polarizing plate intermediate with a phase difference layer, there will still be variations in the axial direction of each punched final product. Such a problem can be avoided by punching out in batches. That is, the polarizing plate sheet 32 with a phase difference layer can be obtained, the absorption axis direction and the slow axis direction of each product are precisely controlled, and the variations in the absorption axis direction and the slow axis direction of each product are very small (substantially no variations).

The above-mentioned oblique punching can be performed in the following manner: the edge of the polarizing plate intermediate body with the phase difference layer attached is detected, and the direction of the punching knife is adjusted according to the detected information, and then the punching knife with the adjusted direction is used for punching. It is preferable to detect the long side and the short side of the polarizing plate intermediate body with the phase difference layer attached. If it is the above-mentioned structure, more precise punching can be performed.

As described above, a polarizing plate with a phase difference layer (a polarizing plate with a phase difference layer as a final product) 32 can be obtained. The obtained polarizing plate with a phase difference layer can be, for example, a rectangle with a long side of 10 mm to 70 mm and a short side of 10 mm to 70 mm, or a rectangle with a long side of 20 mm to 40 mm and a short side of 10 mm to 30 mm, or more specifically, a rectangle with a long side of 30 mm and a short side of 20 mm. The polarizing plate with a phase difference layer can be used as a circular polarizing plate for VR goggles, for example.

According to the implementation form of the present invention, by adopting a process completely different from the known process, a polarizing plate with a phase difference layer in which the absorption axis direction of the polarizer and the slow axis direction of the phase difference layer are extremely precisely controlled can be efficiently manufactured. This effect is particularly significant in the manufacture of very small polarizing plates with phase difference layers. Specifically, it is described as follows. In the known manufacturing method, the phase difference film is typically punched out from the blank roll of the phase difference film in a direction inclined relative to the long strip direction of the blank roll (for example, a 45° direction), and the polarizing plate is punched out from the blank roll of the polarizing plate in the long strip direction of the blank roll. This is because the yield rate will be high if this is done, and the axial offset problem of the phase difference layer (phase difference film) in the polarizing plate with phase difference layer of known size will not become serious. On the other hand, when manufacturing a very small polarizing plate with phase difference layer (for example, for VR goggles: a size of about 20mm×30mm), if the manufacturing method as described above is used, there will be a situation where the characteristics of each final product vary greatly to an unacceptable degree. According to the embodiment of the present invention, the phase difference film is punched out from the blank roll of the phase difference film while correcting the axis deviation, and the polarizing plate is punched out from the blank roll of the polarizing plate in a direction inclined relative to the long strip direction of the blank roll (for example, a 45° direction), thereby, even if a very small polarizing plate with a phase difference layer is finally produced, the absorption axis direction of the polarizer and the slow axis direction of the phase difference layer can still be obtained. At this time, although the waste part of the blank roll is more than the conventional manufacturing method, the number of unacceptable final products is overwhelmingly reduced, so the overall yield rate is increased. Alternatively, even if the overall yield rate decreases, the axis offset of the polarizing plate with a phase difference layer cannot be detected without destroying the final product (such as VR goggles), so it is still useful in terms of quality assurance of the final product.

Industrial Applicability The manufacturing method of the embodiment of the present invention is applicable to the manufacture of polarizing plates with phase difference layers, and in particular, is applicable to the manufacture of very small polarizing plates with phase difference layers (for example, for VR goggles).

10: Stock roll of phase difference film 12: Phase difference layer intermediate 20: Stock roll of polarizing plate 22: Polarizing plate intermediate 30: Polarizing plate intermediate with phase difference layer 32: Polarizing plate with phase difference layer (polarizing plate with phase difference layer as the final product) A: Absorption axis S: Slow axis

Figures 1(a) and 1(b) are schematic diagrams illustrating the process of obtaining a phase difference layer intermediate in the method for manufacturing a polarizing plate with a phase difference layer in the embodiment of the present invention. Figures 2(a) to 2(c) are schematic diagrams illustrating the process of obtaining a polarizing plate intermediate in the method for manufacturing a polarizing plate with a phase difference layer in the embodiment of the present invention. Figures 3(a) to 3(c) are schematic diagrams illustrating the process of obtaining a polarizing plate sheet with a phase difference layer as a final product in the method for manufacturing a polarizing plate with a phase difference layer in the embodiment of the present invention.

10: Phase difference film blank roll

12: Phase difference layer intermediate

S: Slow axis

Claims (4)

A method for manufacturing a polarizing plate with a phase difference layer comprises the following steps: A blank roll of a phase difference film having a slow axis in the longitudinal direction is punched into a predetermined size while correcting the offset of the slow axis in the width direction of the blank roll relative to the longitudinal direction, thereby obtaining a single phase difference layer intermediate having a slow axis in the longitudinal direction; A blank roll of a polarizing plate having an absorption axis in the longitudinal direction is punched into the same size as the phase difference layer intermediate, thereby obtaining a single polarizing plate intermediate having an absorption axis in a direction of 45° relative to the longitudinal direction; The phase difference layer intermediate and the polarizing plate intermediate are bonded together in such a way that their outer edges are aligned, thereby obtaining a phase difference layer-attached polarizing plate intermediate in which the absorption axis of the polarizing plate and the slow axis of the phase difference layer form an angle of 45°; and, The phase difference layer-attached polarizing plate intermediate is punched to obtain a phase difference layer-attached polarizing plate sheet having a predetermined size of absorption axis in the long side direction. In the manufacturing method of claim 1, 3 to 16 pieces of the aforementioned phase difference layer intermediates are obtained in the width direction from the aforementioned phase difference film blank roll. The manufacturing method of claim 1 or 2, wherein the phase difference layer intermediate and the polarizing plate intermediate are rectangular with a short side of 75 mm to 310 mm. As in the manufacturing method of claim 3, wherein the polarizing plate with a phase difference layer is a rectangle with a long side of 10 mm to 70 mm and a short side of 10 mm to 70 mm.

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