KR20120070092A - Polarizing plate and liquid crystal display device comprising the same - Google Patents

Abstract

PURPOSE: A polarizing plate and a liquid crystal display device comprising the same are provided to improve productivity and processing efficiency by continuously directly attaching a laminate including a polarizer and a laminate including a reflective polarizer through a roll-to-roll process. CONSTITUTION: A polarizing plate comprises a polarizer protection film(11), a polarizer(12), an inclined extended λ/2 film(16), an adhesive layer(14), and a reflective polarizer(15). The polarizer protection film is formed of a film with superior transparency, mechanical strength, thermal stability, moisture shield property, and isotropy and attached to one or two sides of the polarizer for protecting the mechanically weak polarizer.

Description

POLARIZING PLATE AND LIQUID CRYSTAL DISPLAY DEVICE COMPRISING THE SAME}

The present invention relates to a polarizing plate which can provide excellent display quality by improving brightness when applied to a liquid crystal display device and can be continuously manufactured by a roll-to-roll process, and a liquid crystal display device having the same.

As the size and size of liquid crystal display devices (LCDs) have increased in recent years, there has been an increasing demand for improving display quality in terms of luminosity, contrast, wide viewing angle, and luminance in polarizers.

In order to improve luminance, a reflective polarizer called a brightness enhancement film is disposed between the backlight unit and the lower polarizer in the liquid crystal display, and the light absorbed by the lower polarizer is reflected and reused. That is, the lower plate polarizing plate with a reflective polarizer was proposed.

As shown in FIG. 1, the lower polarizing plate with a reflective polarizer includes a polarizer protective film 13 positioned below a normal polarizing plate including a polarizer protective film 11, a polarizer 12, and a polarizer protective film 13. It has a structure in which the reflective polarizer 15 is bonded to one surface of the substrate through the pressure-sensitive adhesive layer 14. At this time, the transmission axis of the reflective polarizer should be bonded to coincide with each other.

However, as shown in Fig. 2, the transmission axis of the polarizer is perpendicular to the stretching direction of the polarizer, whereas the transmission axis of the reflective polarizer is parallel to the stretching direction of the reflective polarizer which is the same as the stretching direction of the polarizer. Direction (B). That is, since the transmission axes of the polarizer and the reflective polarizer are orthogonal to each other, a separate additional process of adjusting them so that their transmission axes coincide before joining them must be performed.

Due to this, it is difficult to continuously manufacture the lower polarizing plate by directly bonding the polarizing plate and the reflective polarizer by a roll-to-roll process without any additional process. In addition, mass production through automation is not easy, there was a disadvantage that the fairness is not good.

An object of the present invention is to provide a polarizing plate which can provide excellent display quality by improving luminance and can be manufactured through a simple and continuous process.

In addition, the present invention provides a method of manufacturing a polarizing plate capable of directly bonding the polarizer and the reflective polarizer through a roll-to-roll process without any additional process for adjusting the transmission axis of the polarizer and the reflective polarizer to match. For other purposes.

In addition, another object of the present invention is to provide a liquid crystal display device provided with a lower polarizing plate in which the polarizing plate is disposed on the backlight unit side.

1. Reflective polarizer; An obliquely stretched λ / 2 film for rotating the polarization axis of light passing through the reflective polarizer by 90 °; And a polarizer for passing the light passing through the obliquely stretched λ / 2 film, the polarizer being disposed so that the transmission axis of the reflective polarizer and the transmission axis are perpendicular to each other.

2. The polarizing plate according to the above 1, wherein the pressure-sensitive adhesive layer is provided between the reflective polarizer and the diagonally stretched λ / 2 film.

3. In the above 1, the polarizing plate provided with a polarizer protective film between the diagonally stretched λ / 2 film and the polarizer.

4. The polarizing plate according to the above 1, wherein the polarizer protective film is provided on the side of the two surfaces of the polarizer in which the diagonally stretched λ / 2 film is not located.

5. arranging a first laminate including a reflective polarizer and a second laminate including a polarizer such that the transmission axis of the reflective polarizer and the transmission axis of the polarizer are perpendicular to each other; Bonding a diagonally stretched λ / 2 film to a surface to be bonded to the second laminate of the first laminate; And bonding the first laminate and the second laminate to which the diagonally stretched λ / 2 film is bonded.

6. Disposing a first laminate including a reflective polarizer and a second laminate including a polarizer such that the transmission axis of the reflective polarizer and the transmission axis of the polarizer are perpendicular to each other; Bonding a diagonally stretched λ / 2 film to a surface to be bonded to the first laminate of the second laminate; And bonding a second laminate in which the first laminate and the obliquely stretched λ / 2 film are bonded to each other.

7. disposing a first stack including a reflective polarizer and a second stack including a polarizer such that a transmission axis of the reflective polarizer and a transmission axis of the polarizer are perpendicular to each other; Disposing an obliquely stretched λ / 2 film between the first laminate and the second laminate; And bonding the first laminate, the diagonally stretched λ / 2 film and the second laminate at the same time.

8. The method of any one of 5 to 7, wherein the polarizing plate is continuously performed in a roll-to-roll process.

9. The liquid crystal display device provided as the lower polarizing plate of the polarizing plate of any one of the above 1 to 4 is disposed on the backlight unit side.

The polarizing plate according to the present invention may be applied to a lower polarizing plate positioned on the backlight unit side of various image display devices including a liquid crystal display, thereby improving luminance and providing excellent display quality.

In addition, according to the manufacturing method of the lower polarizing plate of the present invention, the laminate including the polarizer and the laminate including the reflective polarizer is roll-to-without a separate process of adjusting the transmission axes of the polarizer and the reflective polarizer to coincide. Direct bonding can be performed continuously in a roll process, thereby improving processability and productivity.

1 is a cross-sectional view of a polarizing plate with a conventional reflective polarizer,
2 is a view showing the transmission axis of the polarizer and the reflective polarizer,
3 is a cross-sectional view of a polarizing plate according to an embodiment of the present invention,
4 is a cross-sectional view of a polarizer according to another embodiment of the present invention.

The present invention relates to a polarizing plate which can provide excellent display quality by improving brightness when applied to a liquid crystal display device and can be continuously manufactured by a roll-to-roll process, and a liquid crystal display device having the same.

Hereinafter, the present invention will be described in detail.

Polarizing plate of the present invention is a reflective polarizer; An obliquely stretched λ / 2 film for rotating the polarization axis of light passing through the reflective polarizer by 90 °; And a polarizer for passing the light passing through the obliquely stretched λ / 2 film, the polarizer disposed so that the transmission axis of the reflective polarizer and the transmission axis are perpendicular to each other.

As shown in FIG. 3, the polarizing plate according to the embodiment of the present invention includes a polarizer protective film 11, a polarizer 12, an obliquely stretched λ / 2 film 16, an adhesive layer 14, and a reflective polarizer ( 15) may be provided in order.

In addition, the polarizing plate according to another embodiment of the present invention, as shown in Figure 4, a polarizer protective film 11, a polarizer 12, a polarizer protective film 13, a gradient stretched λ / 2 film 16, pressure-sensitive adhesive The layer 14 and the reflective polarizer 15 may be provided in order.

The conventional polarizing plate has a structure in which the protective film 11 is bonded to one surface of the polarizer 12 or the protective films 11 and 13 are bonded to two surfaces of the polarizer 12.

The polarizer protective films 11 and 13 are bonded to one or both surfaces of the polarizer to protect the mechanically weak polarizer, and may use a film excellent in transparency, mechanical strength, thermal stability, moisture shielding, and isotropy. Specific examples include polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate and polybutylene terephthalate; Cellulose resins such as diacetyl cellulose and triacetyl cellulose; Polycarbonate resin; Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene resins such as polystyrene and acrylonitrile-styrene copolymers; Polyolefin resins such as polyethylene, polypropylene, cycloolefin, or polyolefin having a norbornene structure, and an ethylene-propylene copolymer; Vinyl chloride-based resins; Amide resins such as nylon and aromatic polyamides; Imide resin; Polyether sulfone resin; Sulfone resins; Polyether ether ketone resins; Sulfided polyphenylene resins; Vinyl alcohol-based resins; Vinylidene chloride-based resins; Vinyl butyral resin; Allyl resins; Polyoxymethylene resin; And films composed of thermoplastic resins such as epoxy resins, and the like, and films composed of blends of the above thermoplastic resins may also be used. Moreover, you may use the film which consists of thermosetting resins, such as a (meth) acrylic-type, a urethane type, an acryl urethane type, an epoxy type, a silicone type, or an ultraviolet curable resin.

The polarizer protective film may be an unstretched, uniaxial or biaxially stretched film, or may be a film having an optical compensation function. Moreover, these thickness is 1-500 micrometers normally, Preferably it is 1-300 micrometers.

The polarizer 12 is a dichroic substance adsorbed on the polymer film.

The polymer film constituting the polarizer is not particularly limited as long as it is a film that can be dyed with a dichroic substance such as iodine, and specifically, a polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymer film, and an ethylene-vinyl alcohol copolymer film. Hydrophilic polymer films such as cellulose films, partially gumified films thereof, and the like; Or a polyene alignment film such as a dehydrated polyvinyl alcohol-based film, a dehydrochloric acid-treated polyvinyl alcohol-based film, or the like. Among them, polyvinyl alcohol-based films are preferred in that they are excellent in effect of enhancing uniformity in polarization degree and excellent in dyeing affinity for dichroic substances.

A polarizer is usually manufactured through the process of extending | stretching a polymer film as mentioned above, the process of dyeing and adsorb | sucking with a dichroic substance, the process of crosslinking with the boric acid aqueous solution, and the process of washing with water and drying. In addition, the polarizer may include boric acid, zinc sulfate, zinc chloride, or the like as necessary.

The thickness of the polarizer is not particularly limited and may be usually 5 to 80 μm.

The polarizer protective film and the polarizer are usually bonded using an aqueous adhesive composition. More specifically, the adhesive is applied by applying a water-based adhesive to at least one of the bonding surfaces of the polarizer or the polarizer protective film, superimposing them, and drying. As the coating method, a method known in the art, such as a casting method, a meyer bar, an air knife, gravure, a reverse roll, a kiss roll, a spray, a blade, a die coater, a casting, a spin coating, or the like can be used. The drying treatment is performed using, for example, hot air and may be performed at a drying temperature of 40 to 100 ° C., preferably at 60 to 100 ° C. for 20 to 1,200 seconds.

The polarizing plate of the present invention has a structure in which the reflective polarizer 15 is bonded to the usual polarizing plate configured as described above via the pressure-sensitive adhesive layer 14.

The pressure-sensitive adhesive layer 14 is a layer for bonding the reflective polarizer 15 to one surface of the polarizer 12 or the polarizer protective film 13, and is an acrylic resin, a silicone resin, a styrene resin, or a polyester resin as an adhesive resin. It may be formed from a pressure-sensitive adhesive composition comprising a resin, a rubber-based resin or a urethane-based resin alone or in a mixture of two or more thereof.

The reflective polarizer 15 has a function of reducing light loss and increasing luminance by repeating a process of transmitting some of the incident light, reflecting some of the light, and reentering the same, that is, the same as an optical film commonly referred to as a brightness enhancement film. It is an optical film having a function. For example, in order to reduce the loss of reflected and extinguished light when the light supplied from the backlight unit of the liquid crystal display is incident on the liquid crystal panel, part of the light component is transmitted and part is reflected. Here, the reflected light component is reflected through the reflective sheet of the backlight unit and reincident to the reflective polarizer. In addition, the light re-incident to the reflective polarizer is subjected to the above series of steps to minimize the loss of light. Such reflective polarizers are called brightness enhancement films or double brightness enhancement films (DBEF).

The reflective polarizer may be a single sheet or a laminate of two or more sheets.

The kind of the reflective polarizer is not particularly limited, and a grid polarizer, two or more multilayer thin film laminates composed of two or more materials having different refractive indices (for example, vapor-deposited multilayer thin films having different refractive indices used in beam splitters, etc.), A laminate obtained by stretching two or more resin laminates composed of two or more resins having different refractive indices, a laminate of a cholesteric liquid crystal layer and a λ / 4 film (e.g., Nitto Denko PCF), an anisotropic scattering polarizer ( For example, 3M DRP), an anisotropic diffraction grating, etc. are mentioned. Furthermore, those disclosed in U.S. Patent Nos. 6,368,699, International Patents WO95 / 17303, WO95 / 17691, WO95 / 17692, WO95 / 17699, WO96 / 19347 and WO99 / 36262, dual brightness enhancing films (e.g., DBEF from 3M) Etc. can also be used.

In addition, a reflective polarizer may further be laminated with a film for imparting various functionalities, for example, an optical film such as a diffusion film, a prism film, and the like. At this time, it is preferable that the optical film is laminated on the side of the backlight unit of the reflective polarizer so as not to cause deformation of polarized light.

When the reflective polarizer is bonded to the polarizer, it must be bonded so that its transmission axis coincides with the transmission axis of the polarizer. Usually, the transmission axis of the polarizer is perpendicular to the stretching direction of the polarizer (Fig. 2A), while the transmission axis of the reflective polarizer is parallel to the stretching direction B of the reflective polarizer. That is, the transmission axis of the reflective polarizer and the transmission axis of the polarizer are orthogonal to each other, and in order to bond them, a separate additional process of adjusting the transmission axis of the polarizer is required.

In view of this point, in the present invention, the phase difference film between the polarizer and the reflective polarizer can be directly bonded in a state where their transmission axes are orthogonal without additional process of adjusting the transmission axes of the polarizer and the reflective polarizer to coincide. In particular, it is characterized in that the diagonally stretched λ / 2 film is provided.

The diagonally stretched λ / 2 film 16 is a kind of retardation film having a function of rotating the polarization axis of linearly polarized light by 90 ° and is a film produced by diagonally stretching.

The material of the diagonally stretched [lambda] / 2 film is not particularly limited, and examples thereof include a material having a positive intrinsic birefringence value, a negative material, or a mixed material thereof.

A material with a positive intrinsic birefringence value refers to a material that possesses properties that exhibit optically positive uniaxiality when the molecules are oriented with a uniaxial order. For example, when the positive material is a resin, it refers to a resin in which the refractive index of the light in the alignment direction is greater than the refractive index of the light in the direction orthogonal to the alignment direction when light is incident on the layer in which the molecules have a uniaxial orientation. Specific examples include olefin resins such as polyethylene, polypropylene, norbornene polymers and cycloolefin polymers; Polyester-based resins such as polyethylene terephthalate and polybutylene terephthalate; Polyarylene sulfide-based resins such as polyphenyl sulfide; Polyvinyl alcohol-based resins; Polycarbonate resin; Polyallylate resins; Cellulose resins; Polyether sulfone resin; Polysulfone resins; Polyallyl sulfone resin; Polyvinyl chloride-based resins, or poly (2), ternary and the like copolymerized resins thereof. These can be used individually or in mixture of 2 or more types.

In addition, a material having a negative intrinsic birefringence value refers to a material having a property of optically exhibiting negative uniaxiality when molecules are oriented with a uniaxial order. For example, when the negative material is a resin, it refers to a resin in which the refractive index of the light in the alignment direction becomes smaller than the refractive index of the light in the direction orthogonal to the alignment direction when light is incident on the layer in which the molecules have a uniaxial orientation. Specific examples thereof include styrene resins such as polystyrene, styrene or derivatives thereof and copolymers of other monomers; Polyacrylonitrile resins; Polymethyl methacrylate resins; Cellulose ester-based resins or these polymembered (binary, ternary, etc.) copolymerized resins; These can be used individually or in mixture of 2 or more types.

Gradient stretching λ / 2 in such a way that the elongated film made of such a material is diagonally stretched so that the direction of slow axis is formed in a diagonal direction rather than parallel or perpendicular to the MD (machine direction) direction by varying the moving speeds at both ends in the stretching process. Films can be produced.

The diagonally stretched [lambda] / 2 film is rotated by turning the polarization axis of the linearly polarized light that is supplied from the backlight and transmitted through the reflective polarizer by 90 degrees to adjust the polarization axis of the linearly polarized light to coincide with the transmission axis of the polarizer.

The diagonally stretched λ / 2 film may be bonded to one side of the backlight unit side surface of the polarizer or one side of the polarizer protective film of the backlight unit side through an adhesive layer or an adhesive layer.

In the roll-to-roll process, such an obliquely stretched λ / 2 film has a direction of the highest refractive index of 45 ° with respect to the direction of the roll, thereby rotating the polarization axis of the light supplied from the backlight and passing through the reflective polarizer by 90 °. It is possible to directly bond in a roll-to-roll process without having the transmission axes of the polarizers and the reflective polarizers whose transmission axes are perpendicular to each other do not coincide with each other.

The polarizing plate of the present invention may further include a conventional diffusion protection film on one side of the reflective polarizer 15, that is, the side of the backlight unit.

The polarizing plate of the present invention configured as described above has an obliquely stretched λ / 2 film provided between the polarizer and the reflective polarizer, and uses the obliquely stretched λ / 2 film as the polarization axis of the light supplied from the backlight unit and transmitted through the reflective polarizer. By rotating it by 90 [deg.], The polarization axis of the light passing through the reflective polarizer and the transmission axis of the polarizer are adjusted in a parallel state, i.e., in an orthogonal state. Through this, in manufacturing a polarizing plate with a reflective polarizer can be directly bonded without any additional process to adjust the transmission axis of the polarizing plate and the reflective polarizer of the polarizing plate orthogonal to each other orthogonal to each other in parallel. That is, by applying a roll-to-roll process to produce continuously, not only productivity and processability can be improved, but also luminance of a liquid crystal display device can be improved to provide excellent display quality.

According to an exemplary embodiment of the present invention, a method of manufacturing a polarizing plate includes a first laminate including a reflective polarizer and a second laminate including a polarizer such that a transmission axis of the reflective polarizer and a transmission axis of the polarizer are perpendicular to each other. Deploying; Bonding a diagonally stretched λ / 2 film to a surface to be bonded to the second laminate of the first laminate; And bonding the first laminate and the second laminate to which the diagonally stretched λ / 2 film is bonded.

In another embodiment, a method of manufacturing a polarizing plate may include disposing a first stack including a reflective polarizer and a second stack including a polarizer such that a transmission axis of the reflective polarizer and a transmission axis of the polarizer are perpendicular to each other. ; Bonding a diagonally stretched λ / 2 film to a surface to be bonded to the first laminate of the second laminate; And bonding the second laminate in which the first laminate and the diagonally stretched λ / 2 film are bonded to each other.

According to another embodiment of the present invention, a method of manufacturing a polarizing plate includes arranging a first laminate including a reflective polarizer and a second laminate including a polarizer such that a transmission axis of the reflective polarizer and a transmission axis of the polarizer are perpendicular to each other. step; Disposing an obliquely stretched λ / 2 film between the first laminate and the second laminate; And And simultaneously bonding the first laminate, the diagonally stretched λ / 2 film, and the second laminate.

Arranging the transmission axis of the reflective polarizer included in the first laminate and the polarizer included in the second laminate perpendicular to each other is preparing the first laminate and the second laminate parallel without any manipulation. .

Since the transmission axis is orthogonal to each other, the polarizer and the reflective polarizer generally manufactured and marketed are characterized in that the present invention is arranged in such a state that the transmission axes thereof are not adjusted in parallel, i.

The first laminate may be composed of a reflective polarizer / adhesive layer, and an obliquely stretched λ / 2 film may be bonded onto the adhesive layer.

In addition, the second laminate may be composed of a polarizer protective film / polarizer, a polarizer protective film / polarizer / polarizer protective film, the oblique stretching λ / 2 film may be bonded on the polarizer or polarizer protective film.

At this time, an obliquely stretched λ / 2 film may be bonded to only one of the first laminate and the second laminate.

In this invention, it is important to bond so that the diagonal stretched (lambda) / 2 film may be arrange | positioned between a reflective polarizer and a polarizer at the time of bonding of a 1st laminated body and a 2nd laminated body.

Bonding may be performed through an adhesive (layer) or pressure-sensitive adhesive (layer), and may be bonded using the pressure-sensitive adhesive layer provided on the bonding surface of the laminate. As the adhesive (layer), the same adhesive composition used for bonding an ordinary adhesive composition such as a polarizer and a polarizer protective film can be used. In addition, the adhesive (layer) can use the same adhesive composition containing ordinary adhesive resin as the adhesive layer for bonding a reflective polarizer, for example.

In particular, the present invention is characterized in that the joining of the first laminate and the second laminate is carried out continuously using a roll-to-roll process. That is, the first laminate and the second laminate may be directly bonded without a separate process of manipulating the directions of the first laminate and the second laminate such that the transmission axes of the polarizer and the reflective polarizer are coincident with each other.

Through such a manufacturing method, the polarizing plate may be manufactured by a simple and continuous process, thereby improving processability and productivity.

The polarizing plate of the present invention constructed and manufactured as described above can be applied both as a lower polarizing plate positioned on the backlight unit side of various image display devices as well as a normal liquid crystal display device. Here, the reflective polarizer of the polarizing plate is provided to be located on the backlight unit side.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but these examples are merely illustrative of the present invention and are not intended to limit the scope of the appended claims. It is apparent to those skilled in the art that various changes and modifications can be made to the present invention, and such modifications and changes belong to the appended claims.

Example

Example  One

The 1st laminated body in which the adhesive layer was formed in one surface of the reflective polarizer (3M company DBEF) was manufactured. Moreover, the diagonal stretched (lambda) / 2 film was bonded through the water-based adhesive agent on the PVA polarizer of the 2nd laminated body which is a iodine type polarizing plate comprised of a PVA polarizer orthogonal to the transmission axis of a reflective polarizer with a TAC film / transmission axis. A diagonal stretched lambda / 2 film bonded to the second laminate through the pressure-sensitive adhesive layer of the first laminate is bonded, and a diagonal stretched lambda / 2 between the reflective polarizer of the first laminate and the polarizer of the second laminate A polarizing plate provided with a film was prepared. At this time, the bonding of the iodine polarizing plate and the diagonally stretched [lambda] / 2 film and the bonding of the first laminate and the second laminate were performed simultaneously in a roll-to-roll process.

Example  2

It carried out similarly to Example 1, but used the iodine type polarizing plate comprised from TAC film / PVA polarizer / TAC film as a 2nd laminated body.

Example  3

The diagonal stretched (lambda) / 2 film was bonded through the adhesive layer of the 1st laminated body comprised from the reflective polarizer / adhesive layer. A 2nd laminated body which is an iodine type polarizing plate comprised from the PVA polarizer whose TAC film / transmission axis orthogonal to the transmission axis of a reflective polarizer was prepared. The obliquely stretched λ / 2 film bonded to the first laminate was bonded to the PVA polarizer of the second laminate via an adhesive, and the obliquely stretched between the reflective polarizer of the first laminate and the polarizer of the second laminate. A polarizing plate with a λ / 2 film was prepared. At this time, the bonding of the reflective polarizer and the diagonally stretched [lambda] / 2 film and the bonding of the first laminate and the second laminate were performed simultaneously in a roll-to-roll process.

Comparative example  One

An iodine-based polarizing plate composed of a first laminate having a pressure-sensitive adhesive layer formed on one side of the reflective polarizer and a PVA polarizer whose TAC film / transmission axis was orthogonal to the transmission axis of the reflective polarizer was prepared as a second laminate. The direction of the first laminate was shifted by 90 ° so that the transmission axis of the reflective polarizer of the first laminate and the PVA polarizer of the second laminate were coincident. Thereafter, the polarizing plate was manufactured by bonding the PVA polarizer of the second laminate to the medium via the pressure-sensitive adhesive layer of the first laminate. At this time, the bonding of the first laminate and the second laminate was performed by a sheet-to-roll process.

Test Example

The production amount (m / min) of the polarizing plate produced per unit time in the Examples and Comparative Examples was confirmed.

division Example 1  Example 2 Example 3 Comparative Example 1 Production rate (m / min) 11 11 10 2.5

As shown in Table 1, according to the present invention, Examples 1 to 3 manufactured to have an inclined stretched λ / 2 film between the polarizer and the reflective polarizer according to the present invention separately control the transmission axes of the polarizer and the reflective polarizer to match. It is possible to manufacture the polarizing plate directly by using a roll-to-roll process because it does not require the additional process of, and it can be seen that the yield per unit time is higher than that of Comparative Example 1, which does not use the diagonally stretched λ / 2 film. there was. Specifically, it was possible to manufacture the lower plate polarizing plate with a high yield of 4 times or more per unit time.

11: polarizer protective film 12: polarizer
13: polarizer protective film 14: adhesive layer
15: reflective polarizer 16: obliquely stretched λ / 2 film

Claims (9)

Reflective polarizers; An obliquely stretched λ / 2 film for rotating the polarization axis of light passing through the reflective polarizer by 90 °; And a polarizer for passing the light passing through the obliquely stretched λ / 2 film, the polarizer being disposed so that the transmission axis of the reflective polarizer and the transmission axis are perpendicular to each other.
The polarizing plate according to claim 1, wherein an adhesive layer is provided between the reflective polarizer and the diagonally stretched λ / 2 film.
The polarizing plate of claim 1, wherein a polarizer protective film is provided between the diagonally stretched λ / 2 film and the polarizer.
The polarizing plate of claim 1, wherein a polarizer protective film is provided on a side of the two surfaces of the polarizer in which the obliquely stretched λ / 2 film is not located.
Disposing a first stack including a reflective polarizer and a second stack including a polarizer such that a transmission axis of the reflective polarizer and a transmission axis of the polarizer are perpendicular to each other;
Bonding a diagonally stretched λ / 2 film to a surface to be bonded to the second laminate of the first laminate; And
A method of manufacturing a polarizing plate comprising the step of bonding the first laminate and the second laminate, the obliquely stretched λ / 2 film is bonded.
Disposing a first stack including a reflective polarizer and a second stack including a polarizer such that a transmission axis of the reflective polarizer and a transmission axis of the polarizer are perpendicular to each other;
Bonding a diagonally stretched λ / 2 film to a surface to be bonded to the first laminate of the second laminate; And
A method of manufacturing a polarizing plate comprising the step of bonding the first laminate and the second laminate bonded to the diagonally stretched [lambda] / 2 film.
Disposing a first stack including a reflective polarizer and a second stack including a polarizer such that a transmission axis of the reflective polarizer and a transmission axis of the polarizer are perpendicular to each other;
Disposing an obliquely stretched λ / 2 film between the first laminate and the second laminate; And
And bonding the first laminate, the obliquely stretched λ / 2 film and the second laminate at the same time.
The manufacturing method of the polarizing plate of any one of Claims 5-7 performed continuously by a roll-to-roll process.
The liquid crystal display device provided as the lower plate polarizing plate in which the polarizing plate of any one of Claims 1-4 is arrange | positioned at the backlight unit side.

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