CN108885369B

CN108885369B - Polarizing plate set and IPS mode liquid crystal display device using the same

Info

Publication number: CN108885369B
Application number: CN201780021170.XA
Authority: CN
Inventors: 松本寿和
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2016-03-31
Filing date: 2017-03-22
Publication date: 2021-03-16
Anticipated expiration: 2037-03-22
Also published as: KR20180124966A; CN108885369A; KR102290943B1

Abstract

A polarizing plate group for a specific IPS mode liquid crystal cell capable of ensuring good visibility even in an environment of strong external light, the polarizing plate group comprising viewing-side polarizing plates (30, 34) and a rear-side polarizing plate (50) and being bonded to both sides of an IPS mode liquid crystal cell (60) having an in-plane retardation value of 100nm to 200nm, the absorption axis (1) of the viewing-side polarizing plates (30, 34) being substantially orthogonal to the absorption axis (5) of the rear-side polarizing plate, the viewing-side polarizing plates (30, 34) having a polarizing plate (30) and a lambda/4 plate (34), and an IPS mode liquid crystal display device using the polarizing plate group, wherein an angle formed by the absorption axis (1) of the viewing-side polarizing plates (30, 34) and the retardation axis (2) of the lambda/4 plate (34) is substantially 45 DEG, the slow axis (2) of the lambda/4 plate (34) is arranged in a substantially orthogonal relationship with respect to the initial alignment direction (3) of the IPS mode liquid crystal cell (60).

Description

Polarizing plate set and IPS mode liquid crystal display device using the same

Technical Field

The present invention relates to a polarizing plate and an IPS mode liquid crystal display device using the same.

Background

In recent years, liquid crystal displays that consume low power, operate at low voltage, and are lightweight and thin have rapidly become popular as information display devices such as mobile phones, mobile information terminals, monitors for computers, and televisions. With the development of liquid crystal technology, various modes of liquid crystal displays have been proposed, and problems of liquid crystal displays such as response speed, contrast, narrow viewing angle, and the like have been gradually eliminated.

As the opportunities for outdoor use increase in mobile phones and mobile information terminals, when external light such as sunlight is strong, a liquid crystal display device including a conventional liquid crystal cell and a conventional polarizing plate group has a problem that reflection of the external light is strong and a liquid crystal screen is difficult to visually recognize.

As a countermeasure against this problem, a low reflection layer is generally provided on the surface of the viewing-side polarizing plate to reduce reflection of external light, or a circular polarizing plate is used as the viewing-side polarizing plate to reduce reflection of external light.

However, the visibility is significantly reduced in an environment where the illuminance of external light exceeds 5000lux only by the low reflection layer. In addition, in the IPS mode liquid crystal, the in-plane retardation value is generally 250nm to 380nm, and it is difficult to dispose a circularly polarizing plate as a viewing side polarizing plate.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-128498

Disclosure of Invention

Problems to be solved by the invention

The present invention provides a polarizing plate group for a specific IPS mode liquid crystal cell, which can ensure good visibility even in an environment where the illuminance of external light exceeds 5000lux, and an IPS mode liquid crystal display device using the same.

Means for solving the problems

In order to achieve the above object, the present invention provides the following [1] to [6] as embodiment 1.

[1] A polarizing plate group comprising a viewing side polarizing plate and a back side polarizing plate and used for bonding to both sides of an IPS mode liquid crystal cell having an in-plane retardation of 100nm to 200nm,

the absorption axis of the viewing-side polarizing plate is substantially orthogonal to the absorption axis of the rear-side polarizing plate,

the polarizing plate on the viewing side has a polarizing plate and a lambda/4 plate,

an angle formed by an absorption axis of the polarization plate on the viewing side and a slow axis of the lambda/4 plate is substantially 45 DEG,

the retardation axis of the λ/4 plate is arranged in a substantially orthogonal relationship with respect to the initial alignment direction of the IPS mode liquid crystal cell.

[2] The polarizing plate set according to [1], wherein the viewing-side polarizing plate includes a positive C plate disposed between the liquid crystal cell and the λ/4 plate.

[3] The polarizing plate set according to [1], wherein the viewing-side polarizing plate includes a positive C plate disposed between the polarizing plate of the viewing-side polarizing plate and the λ/4 plate.

[4] The polarizing plate group according to [2] or [3], wherein,

the phase difference value of the positive C plate in the thickness direction is-50 nm to-150 nm.

[5] An IPS mode liquid crystal display device comprising the IPS mode liquid crystal cell having an in-plane retardation of 100nm to 200nm and the polarizing plate group of any one of [1] to [4] disposed therein.

[6] The IPS mode liquid crystal display device of [5], wherein the size of the IPS mode liquid crystal display device is 15 inches or less diagonally.

In addition, the present invention provides the following [7] to [12] as embodiment 2.

[7] A polarizing plate group comprising a viewing side polarizing plate and a back side polarizing plate, and used for respectively bonding both sides of an IPS mode liquid crystal cell having an in-plane retardation of 400nm to 500nm,

the retardation axis of the λ/4 plate is disposed in a substantially parallel relationship with respect to the initial alignment direction of the IPS mode liquid crystal cell.

[8] The polarizing plate set according to [7], wherein the viewing-side polarizing plate includes a positive C plate disposed between the liquid crystal cell and the λ/4 plate.

[9] The polarizing plate set according to [7], wherein the viewing-side polarizing plate includes a positive C plate disposed between the polarizing plate and the λ/4 plate.

[10] The polarizing plate assembly according to [8] or [9], wherein the phase difference value in the thickness direction of the positive C plate is from-50 nm to-150 nm.

[11] An IPS mode liquid crystal display device comprising an IPS mode liquid crystal cell having an in-plane retardation of 400-500 nm and a polarizing plate group as defined in any one of [7] to [10 ].

[12] The IPS mode liquid crystal display device of [11], wherein the size of the IPS mode liquid crystal display device is 15 inches or less diagonally.

In addition, the present invention provides the following [13] to [21] as embodiment 3.

[13] A polarizing plate group comprising a polarizing plate on the viewing side and a polarizing plate on the back side for bonding to both sides of an IPS mode liquid crystal cell having an in-plane retardation of 100nm to 200nm,

the absorption axis of the viewing-side polarizing plate is substantially parallel to the absorption axis of the rear-side polarizing plate,

the viewing side polarizing plate has a first polarizing plate and a lambda/4 plate,

the lambda/4 plate is disposed between the first polarizing plate and the liquid crystal cell,

the back-side polarizing plate has a second polarizer and a lambda/2 plate,

an angle formed by the absorption axis of the rear-side polarizing plate and the slow axis of the lambda/2 plate is substantially 45 DEG,

the slow axis of the lambda/4 plate and the slow axis of the lambda/2 plate are substantially orthogonal to each other,

[14] The polarizing plate set according to [13], wherein the viewing-side polarizing plate includes a positive C plate disposed between the liquid crystal cell and the λ/4 plate,

the rear-side polarizing plate includes a positive C plate disposed between the liquid crystal cell and the λ/2 plate.

[15] The polarizing plate set according to [13], wherein the viewing-side polarizing plate includes a positive C plate disposed between the liquid crystal cell and the λ/4 plate,

the rear-side polarizing plate includes a positive C plate disposed between the second polarizer and the λ/2 plate.

[16] The polarizing plate set according to [13], wherein the viewing-side polarizing plate includes a positive C plate disposed between the first polarizing plate and the λ/4 plate,

[17] The polarizing plate set according to [13], wherein the viewing-side polarizing plate includes a positive C plate disposed between the first polarizing plate and the λ/4 plate,

[18] The polarizing plate group according to any one of [14] to [17], wherein phase difference values in the thickness direction of the front C-plate included in the viewing-side polarizing plate and the front C-plate included in the rear-side polarizing plate are substantially equal.

[19] The polarizing plate assembly according to any one of [14] to [18], wherein the positive C plate has a retardation value in the thickness direction of-50 nm to-150 nm.

[20] An IPS mode liquid crystal display device, which comprises the IPS mode liquid crystal cell having an in-plane retardation of 100nm to 200nm and the polarizing plate group of any one of [13] to [19 ].

[21] The IPS mode liquid crystal display device of [20], wherein the size of the IPS mode liquid crystal display device is 15 inches or less diagonally.

In addition, the present invention provides the following [22] to [30] as embodiment 4.

[22] A polarizing plate group comprising a viewing side polarizing plate and a back side polarizing plate, and used for respectively bonding both sides of an IPS mode liquid crystal cell having an in-plane retardation of 400nm to 500nm,

the back-side polarizing plate has a second polarizer and a lambda/2 plate,

[23] The polarizing plate set according to [22], wherein the viewing-side polarizing plate includes a positive C plate disposed between the liquid crystal cell and the λ/4 plate,

[24] The polarizing plate set according to [22], wherein the viewing-side polarizing plate includes a positive C plate disposed between the liquid crystal cell and the λ/4 plate,

[25] The polarizing plate set according to [22], wherein the viewing-side polarizing plate includes a positive C plate disposed between the first polarizing plate and the λ/4 plate,

[26] The polarizing plate set according to [22], wherein the viewing-side polarizing plate includes a positive C plate disposed between the first polarizing plate and the λ/4 plate,

[27] The polarizing plate group according to any one of [23] to [26], wherein phase difference values in the thickness direction of the front C-plate included in the viewing-side polarizing plate and the front C-plate included in the rear-side polarizing plate are substantially equal.

[28] The polarizing plate assembly according to any one of [23] to [27], wherein the positive C plate has a retardation value in the thickness direction of-50 nm to-150 nm.

[29] An IPS mode liquid crystal display device, which comprises an IPS mode liquid crystal cell having an in-plane retardation of 400-500 nm and a polarizing plate group as set forth in any one of [22] to [28 ].

[30] The IPS mode liquid crystal display device of [29], wherein the size of the IPS mode liquid crystal display device is 15 inches or less diagonally.

Effects of the invention

According to the polarizing plate group of the present invention, it is possible to provide a liquid crystal display device capable of suppressing reflection of external light and ensuring good visibility even in an environment where external light is strong such as outdoors.

Drawings

Fig. 1 is a schematic cross-sectional view showing an example of a preferable layer structure of a polarizing plate group according to embodiment 1 and embodiment 2 of the present invention.

Fig. 2 is a schematic cross-sectional view showing an example of a preferable layer structure of the polarizing plate group according to embodiment 3 and embodiment 4 of the present invention.

Fig. 3 is a schematic diagram showing an example of a preferred axis configuration of an IPS liquid crystal display device according to embodiment 1 of the present invention.

Fig. 4 is a schematic diagram showing an example of a preferred axis configuration of an IPS liquid crystal display device according to embodiment 2 of the present invention.

Fig. 5 is a schematic diagram showing an example of a preferred axis configuration of an IPS liquid crystal display device according to embodiment 3 of the present invention.

Fig. 6 is a schematic diagram showing an example of a preferred axis configuration of an IPS liquid crystal display device according to embodiment 4 of the present invention.

Detailed Description

Hereinafter, a description will be given of a polarizing plate group according to the present invention and a liquid crystal panel using the same with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

Fig. 1(a) to (b) are schematic cross-sectional views showing examples of preferred layer structures of polarizing plates according to embodiment 1 and embodiment 2 of the present invention. Polarizing plates according to embodiments 1 and 2 of the present invention will be described with reference to (a) to (b) of fig. 1. The polarizing plate group shown in fig. 1(a) to (b) includes: as the viewing-side polarizing plate 10, a polarizing plate in which the λ/4 plate 34 and the front C plate 35 are laminated on one surface of the polarizing plate 30, and a polarizing plate in which the brightness enhancement film 61 is laminated on one surface of the polarizing plate 50 as the back-side polarizing plate 20 are provided.

Fig. 2(a) to (d) are schematic cross-sectional views showing examples of preferred layer structures of polarizing plates according to embodiment 3 and embodiment 4 of the present invention. The polarizing plate of the present invention will be described with reference to (a) to (d) of fig. 2. The polarizing plate group shown in fig. 2(a) to (d) includes: as the viewing-side polarizing plate 10, a polarizing plate in which a λ/4 plate 34 and a C-plate 35 are laminated on one surface of a polarizing plate 30, and a polarizing plate in which a λ/2 plate 54 and a C-plate 55 are laminated on one surface of a polarizing plate 50, and a brightness enhancement film 61 is laminated on the other surface of the polarizing plate 50 are used as the back-side polarizing plate 20.

[ Components constituting the polarizing plate on the viewing side and the polarizing plate on the back side ]

The viewing side polarizing plate and the back side polarizing plate of the present invention include a polarizing plate 30 and a polarizing plate 50.

[ polarizing plate ]

The polarizing plates 32 (first polarizing plate 32 ') and 52 (second polarizing plate 52') are generally manufactured by the following processes: a step of uniaxially stretching a polyvinyl alcohol resin film; a step of dyeing the polyvinyl alcohol resin film with a dichroic dye to thereby adsorb the dichroic dye; treating the polyvinyl alcohol resin film having the dichroic dye adsorbed thereon with an aqueous boric acid solution; and a step of washing with water after the treatment with the boric acid aqueous solution.

As the polyvinyl alcohol resin, a resin obtained by saponifying a polyvinyl acetate resin can be used. Examples of the polyvinyl acetate resin include, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, and preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and for example, polyvinyl formal, polyvinyl acetal, or the like modified with aldehydes may be used. The polymerization degree of the polyvinyl alcohol resin is usually about 1,000 to 10,000, and preferably about 1,500 to 5,000.

The film obtained by forming such a polyvinyl alcohol resin into a film can be used as a raw material film for the polarizing plates 32 (first polarizing plate 32 ') and 52 (second polarizing plate 52'). The method for forming the polyvinyl alcohol resin film is not particularly limited, and a known method can be used for forming the film. The thickness of the polyvinyl alcohol-based material film is not particularly limited, but is, for example, about 10 to 150 μm.

The uniaxial stretching of the polyvinyl alcohol resin film may be performed before, simultaneously with, or after the dyeing of the dichroic dye. In the case where the uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before boric acid treatment or in boric acid treatment. In addition, the uniaxial stretching may be performed in the above plural stages.

In the case of uniaxial stretching, the stretching may be performed uniaxially between rolls having different peripheral speeds, or may be performed uniaxially using a heat roll. The uniaxial stretching may be dry stretching in which stretching is performed in the air, or wet stretching in which stretching is performed in a state where the polyvinyl alcohol resin film is swollen with a solvent. The draw ratio is usually about 3 to 8 times.

As a method for dyeing a polyvinyl alcohol resin film with a dichroic dye, for example, a method of immersing a polyvinyl alcohol resin film in an aqueous solution containing a dichroic dye is employed. As the dichroic dye, specifically, iodine or a dichroic dye can be used. The polyvinyl alcohol resin film is preferably subjected to an immersion treatment in water before the dyeing treatment.

When iodine is used as the dichroic dye, a method of immersing a polyvinyl alcohol resin film in an aqueous solution containing iodine and potassium iodide to dye the film is generally employed. The iodine content of the aqueous solution is usually about 0.01 to 1 part by weight per 100 parts by weight of water. The content of potassium iodide is usually about 0.5 to 20 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40 ℃.

The immersion time (dyeing time) in the aqueous solution is usually about 20 to 1, 800 seconds.

On the other hand, when a dichroic dye is used as the dichroic dye, a method of immersing a polyvinyl alcohol resin film in an aqueous solution containing a water-soluble dichroic dye to dye the resin film is generally used. The content of the dichroic dye in the aqueous solution is usually 1X 10 per 100 parts by weight of water^-4About 10 parts by weight, preferably 1X 10^-3About 1 part by weight. The aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80 ℃. The immersion time (dyeing time) in the aqueous solution is usually about 10 to 1, 800 seconds.

The boric acid treatment after dyeing with the dichroic dye can be usually performed by immersing the dyed polyvinyl alcohol resin film in an aqueous solution containing boric acid.

The amount of boric acid in the aqueous solution containing boric acid is usually about 2 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. When iodine is used as the dichroic dye, the aqueous solution containing boric acid preferably contains potassium iodide. The amount of potassium iodide in the aqueous solution containing boric acid is usually about 0.1 to 15 parts by weight, preferably about 5 to 12 parts by weight, per 100 parts by weight of water. The dipping time in the aqueous solution containing boric acid is usually about 60 to 1,200 seconds, preferably about 150 to 600 seconds, and more preferably about 200 to 400 seconds. The temperature of the aqueous solution containing boric acid is usually 50 ℃ or higher, preferably 50 to 85 ℃, more preferably 60 to 80 ℃.

The polyvinyl alcohol resin film treated with boric acid is usually subjected to a water washing treatment. The water washing treatment can be performed by, for example, immersing the boric acid-treated polyvinyl alcohol resin film in water. In the water washing treatment, the temperature of water is usually about 5 to 40 ℃. The dipping time is usually about 1 to 120 seconds.

After washing with water, drying treatment was performed, thereby obtaining polarizing plates 32 (first polarizing plate 32 ') and 52 (second polarizing plate 52'). The drying treatment may be performed using a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually about 30 to 100 ℃, preferably 50 to 80 ℃. The drying time is usually about 60 to 600 seconds, preferably 120 to 600 seconds.

By the drying treatment, the moisture ratios of the polarizing plates 32 (first polarizing plate 32 ') and 52 (second polarizing plate 52') are reduced to a practical level. The water content is usually 5 to 20% by weight, preferably 8 to 15% by weight. If the moisture content is less than 5 wt%, the flexibility of the polarizing plates 32 (first polarizing plate 32 ') and 52 (second polarizing plate 52') is lost, and the polarizing plates 32 (first polarizing plate 32 ') and 52 (second polarizing plate 52') may be damaged or broken after the drying. When the moisture content is higher than 20% by weight, the thermal stability of the polarizing plates 32 (first polarizing plate 32 ') and 52 (second polarizing plate 52') may be deteriorated.

In this way, a polarizing plate in which the dichroic dye is adsorbed and oriented in the polyvinyl alcohol resin film can be manufactured.

The stretching, dyeing, boric acid treatment, water washing, and drying of the polyvinyl alcohol resin film in the process of producing the polarizing plate can be carried out, for example, according to the method described in japanese patent application laid-open No. 2012-159778. As in the method described in this document, a method of forming a polyvinyl alcohol resin layer as a polarizing plate by coating a polyvinyl alcohol resin on a base film is also useful.

In order to suppress the shrinkage force of the polarizing plate in a high-temperature environment to a low level, the thickness of the polarizing plate is preferably 15 μm or less, and more preferably 12 μm or less. The thickness of the polarizing plate is usually 3 μm or more from the viewpoint of imparting good optical characteristics.

By using a polarizing plate in which the shrinkage force in a high-temperature environment is suppressed, it is possible to suppress the change in phase difference due to the strain of the λ/2 plate or the λ/4 plate associated with the shrinkage of the polarizing plate, and it is possible to obtain a polarizing plate with small display unevenness when used in a liquid crystal display device.

When the polarizing plate is kept at a temperature of 80 ℃ for 240 minutes, the shrinkage force per 2mm width in the absorption axis direction is preferably 2N/2mm or less. When the shrinkage force is greater than 2N/2mm, the amount of dimensional change in a high-temperature environment increases, and the shrinkage force of the polarizing plate increases, so that the λ/2 plate and the λ/4 plate are likely to be strained, and further, the polarizing plate tends to be easily cracked. When the stretching ratio is reduced and the thickness of the polarizing plate is reduced, the shrinkage force of the polarizing plate tends to be 2N/2mm or less. The measurement method of the contractile force was performed according to the method of the examples described later.

A protective film is preferably laminated on at least one surface of the polarizing plate, and may have protective films on both surfaces. The

protective films

31a, 31b, 51a, 51b may be formed of a transparent resin film. In particular, it is preferably made of a material having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, and the like. In the present specification, a transparent resin film means a resin film having a monomer transmittance of 80% or more in the visible light range.

The

positive C plates

35, 55, the λ/4 plate 34, and the λ/2 plate 54 function as protective films, and the

protective films

31b and 51b are omitted, and this is also an effective means for making polarizing plates thin. Similarly, it is effective for making the polarizing plate thin by omitting the protective film 51a by providing the brightness enhancement film 61 with a function as a protective film.

As the

protective films

31a, 31b, 51a, and 51b, films made of materials that have been conventionally used as materials for forming protective films, such as cellulose-based resins, chain polyolefin-based resins, cyclic polyolefin-based resins, acrylic-based resins, polyimide-based resins, polycarbonate-based resins, and polyester-based resins, can be used.

These resins may contain suitable additives within a range not impairing transparency.

Examples of the additives include antioxidants, ultraviolet absorbers, antistatic agents, lubricants, nucleating agents, antifogging agents, antiblocking agents, retardation reducing agents, stabilizers, processing aids, plasticizers, impact resistance aids, delustering agents, antibacterial agents, and antifungal agents. These additives may be used in combination.

As a method for forming a film from the above resin, any optimum method may be appropriately selected. For example, it is possible to use: a solvent casting method in which a resin dissolved in a solvent is cast onto a metal belt or drum, and the solvent is dried and removed to obtain a film; and a melt extrusion method in which a resin is heated to a temperature equal to or higher than its melting temperature, kneaded, extruded from a die, and cooled to obtain a film. In the melt extrusion method, a single layer film may be extruded, or a multilayer film may be extruded at the same time.

In addition, as the protective film 31a, a retardation plate obtained by stretching the film for improving visibility when viewing a screen through a polarizing sunglass can be used. From the viewpoint of improving visibility, it is desirable that the retardation plate be disposed so that the angle formed by the slow axis of the λ/4 plate and the absorption axis of the polarizing film is substantially 45 °. When the polarizing plate is laminated with a long polarizing film, it is preferable to stretch the polarizing plate so that the angle with the long longitudinal direction is substantially 45 ° or 135 °, because the polarizing plate can be produced in a roll-to-roll manner.

[ surface treatment layer 36 of protective film 31a ]

The protective film 31a may have a surface treatment layer 36 on the surface opposite to the surface to be bonded to the polarizing plate 32 (first polarizing plate 32'). The surface treatment layer 36 is, for example, a hard coat layer having a fine surface roughness. The pencil hardness of the hard coating is preferably harder than H.

If the pencil hardness is H or less, the surface is easily damaged, and if damaged, the visibility of the liquid crystal display device is deteriorated. Pencil hardness was measured in accordance with JIS K5600-5-4: 1999 "general test methods for coatings-part 5: mechanical properties of the coating film-section 4: the scratch hardness (pencil method) "is determined and is represented by the hardness of the hardest pencil that does not cause damage when a pencil of each hardness is used for writing.

The protective film 31a having the surface treatment layer 36 preferably has a haze value in the range of 0.1 to 45%, more preferably 5 to 40%. If the haze value is greater than 45%, reflection of external light can be reduced, but the density of the black display screen is reduced. Further, if the haze value is less than 0.1%, sufficient antiglare performance cannot be obtained, and external light is reflected on the screen, which is not preferable. Herein, the haze value was measured according to JIS K7136: 2000 "method for determining haze of plastic-transparent Material".

The hard coat layer having fine surface irregularities can be formed by a method of forming a coating film containing organic fine particles or inorganic fine particles on the surface of a resin film; a method of forming a coating film containing organic fine particles or inorganic fine particles or not containing organic fine particles or inorganic fine particles and then pressing the coating film against a roll having an uneven shape, for example, a printing method. Such a coating film can be formed, for example, by a method of applying a coating liquid (curable resin composition) containing a binder component containing a curable resin and organic fine particles or inorganic fine particles to the surface of a resin film.

In addition to the anti-glare treatment (haze-imparting treatment) which also serves as a hard coat layer, the protective film 31a may be subjected to various additional surface treatments such as an antireflection layer, antistatic treatment, antifouling treatment, and antibacterial treatment, or a coating layer containing a liquid crystalline compound, a high molecular weight compound thereof, and the like may be formed on the protective film 31 a. In particular, when an antireflection layer having a reflectance of 3% or less is formed, it is preferably used because it can be seen without deterioration even if it is 10000Lux or more. In addition to the surface treatment, an antistatic function may be provided to other portions of the polarizing plate such as an adhesive layer.

[

protective films

31b, 51b ]

As the

protective films

31b and 51b, a cellulose-based resin or a cyclic polyolefin-based resin is preferable because the retardation value can be easily controlled and obtained.

The cellulose resin may be a cellulose organic acid ester or a cellulose mixed organic acid ester in which a part or all of hydrogen atoms of hydroxyl groups of cellulose are substituted with acetyl groups, propionyl groups, and/or butyryl groups. Examples of the resin include cellulose acetate, propionate, butyrate, and mixed esters thereof. Among them, triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate and the like are preferable.

The cyclic polyolefin resin is obtained by polymerizing a cyclic olefin monomer such as norbornene and another cyclopentadiene derivative in the presence of a catalyst. When such a cyclic polyolefin resin is used, a protective film having a predetermined retardation value described later can be easily obtained.

Examples of the cyclic polyolefin resin include: a resin obtained by ring-opening metathesis polymerization of norbornene or its derivative obtained from cyclopentadiene and olefin or (meth) acrylic acid or its ester as a monomer by Diels-Alder reaction, followed by subsequent hydrogenation; a resin obtained by ring-opening metathesis polymerization using as a monomer tetracyclododecene or a derivative thereof obtained from dicyclopentadiene and olefins or (meth) acrylic acid or esters thereof by a Diels-Alder reaction, followed by subsequent hydrogenation; a resin obtained by subjecting at least 2 monomers selected from the group consisting of norbornene, tetracyclododecene, derivatives thereof and other cyclic olefin monomers to ring-opening metathesis copolymerization in the same manner and then subjecting the resulting product to subsequent hydrogenation; and resins obtained by addition copolymerization of a linear olefin and/or an aromatic compound having a vinyl group to a cyclic olefin such as norbornene, tetracyclododecene or a derivative thereof.

In order to suppress a decrease in the degree of polarization due to the elimination of polarization, the retardation value Rth in the thickness direction of the

protective films

31b, 51b is preferably 10nm or less. The retardation value Rth in the thickness direction is a value obtained by multiplying the thickness of the film by the value obtained by subtracting the refractive index in the thickness direction from the average refractive index in the plane, and is defined by the following formula (a). The in-plane retardation value Re is preferably 10nm or less. The in-plane retardation value Re is a value obtained by multiplying the in-plane refractive index difference by the film thickness, and is defined by the following formula (b).

Rth＝〔(n_x+n_y)/2-n_z〕×d (a)

Re＝(n_x-n_y)×d (b)

In the formula, n_xIs a refractive index in the x-axis direction (in-plane slow phase axis direction) in the film surface, n_yIs a refractive index in the y-axis direction (in-plane phase-advancing axis direction and in-plane direction orthogonal to the x-axis), n_zThe refractive index in the z-axis direction (thickness direction) perpendicular to the film surface, and d is the film thickness.

Here, the phase difference value may be a value at an arbitrary wavelength in the range of about 500 to 650nm, which is the vicinity of the center of visible light, but in the present specification, a phase difference value at a wavelength of 590nm is taken as a standard.

The retardation value Rth in the thickness direction and the retardation value Re in the plane can be measured by using various commercially available retardation meters.

As a method of controlling the in-plane and thickness direction retardation value Rth of the resin film in the range of 10nm or less, there is a method of reducing the strain remaining in the in-plane and thickness direction as much as possible at the time of producing the film. For example, in the solvent casting method, a method of relaxing residual shrinkage strain in the in-plane and thickness directions generated when the casting resin solution is dried by heat treatment or the like can be employed. On the other hand, in the above melt extrusion method, the following methods and the like can be adopted: in order to prevent the resin film from being stretched during the period from extrusion from the die to cooling, the distance from the die to the cooling drum is shortened as much as possible, and the extrusion amount and the rotation speed of the cooling drum are controlled in such a manner that the film is not stretched. In addition, a method of relaxing strain remaining in the obtained film by heat treatment may be employed as in the solvent casting method.

[ lambda/4 plate 34]

The λ/4 plate 34 is preferably made of a material having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, and the like. Examples thereof include polyolefin resins such as chain polyolefin resins (polypropylene resins, etc.) and cyclic polyolefin resins (norbornene resins, etc.); cellulose resins such as cellulose ester resins including cellulose triacetate and cellulose diacetate; a polyester resin; a polycarbonate-based resin; (meth) acrylic resins; a polystyrene-based resin; a liquid crystal composition; or mixtures, copolymers, etc. thereof. Among them, a film formed of a polycarbonate-based resin and a liquid crystal composition is preferably used because of its positive wavelength dispersibility.

Here, the positive wavelength dispersion means that the following formula (c) is satisfied. () The inner number is the measured wavelength (in nm) of the phase difference.

Re(450)＞Re(590)＞Re(650) (c)

In the present invention, the phase difference value Re of the λ/4 plate is 120nm to 160nm at a measurement wavelength of 590 nm. In the present invention, the λ/4 plate preferably has an Nz coefficient defined by the following formula (d) in the range of 0.8 to 1.2. More preferably 0.95 to 1.05.

Nz＝Re/Rth+0.5 (d)

Suitable additives may be incorporated into the λ/4 plate within a range not to impair transparency. Examples of the additives include antioxidants, ultraviolet absorbers, antistatic agents, lubricants, nucleating agents, antifogging agents, antiblocking agents, retardation reducing agents, stabilizers, processing aids, plasticizers, impact resistance aids, delustering agents, antibacterial agents, and antifungal agents. These additives may be used in combination.

The polycarbonate-based resin is an aromatic polycarbonate. The polycarbonate-based resin can be obtained, for example, by a method in which a dihydric phenol and a carbonate precursor are reacted by an interfacial polycondensation method or a melt transesterification method; a method of polymerizing a carbonate prepolymer by a solid-phase transesterification method; and a method of polymerizing a cyclic carbonate compound by a ring-opening polymerization method.

As the dihydric phenol, a homopolymer or a copolymer obtained from at least one dihydric phenol selected from the group consisting of bisphenol a, 2-bis { (4-hydroxy-3-methyl) phenyl } propane, 2-bis (4-hydroxyphenyl) butane, 2-bis (4-hydroxyphenyl) -3-methylbutane, 2-bis (4-hydroxyphenyl) -3, 3-dimethylbutane, 2-bis (4-hydroxyphenyl) -4-methylpentane, 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane and α, α' -bis (4-hydroxyphenyl) -m-diisopropylbenzene is preferably used, and particularly a homopolymer of bisphenol a, and 1, copolymers of 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane with at least one dihydric phenol selected from the group consisting of bisphenol a, 2-bis { (4-hydroxy-3-methyl) phenyl } propane and α, α' -bis (4-hydroxyphenyl) -m-diisopropylbenzene.

As the carbonate precursor, a carbonyl halide, a carbonate ester, a haloformate or the like can be used, and specific examples thereof include phosgene, diphenyl carbonate, and a dihaloformate of a dihydric phenol.

In order to impart a predetermined retardation value to the film formed in this way, it is preferable to perform stretching treatment. The stretching may be any suitable stretching method such as uniaxial stretching, sequential biaxial stretching, simultaneous biaxial stretching, or the like.

The liquid crystal composition preferably has a nematic phase (nematic liquid crystal). The mechanism of expression of liquid crystallinity of a liquid crystal material may be lyotropic or thermotropic. The alignment state of the liquid crystal material is preferably uniform. As the liquid crystal material, for example, a liquid crystal polymer or a liquid crystal monomer can be used. The liquid crystal polymer and the liquid crystal monomer may be used alone or in combination.

In the present invention, when used as a λ/4 plate, a cured layer of the liquid crystal composition is preferred. Specifically, when the liquid crystal composition contains a liquid crystalline monomer, the liquid crystalline monomer preferably contains a polymerizable monomer and/or a crosslinkable monomer. The alignment state of the liquid crystalline monomer can be fixed by polymerizing or crosslinking the liquid crystalline monomer. After the liquid crystal monomers are aligned, the alignment state can be fixed by, for example, polymerizing or crosslinking the liquid crystal monomers with each other. Here, the polymer is formed by polymerization and the three-dimensional network structure is formed by crosslinking, but they are non-liquid crystalline. Therefore, the formed retardation layer does not undergo transition to a liquid crystal phase, a glass phase, or a crystal phase due to a temperature change unique to the liquid crystalline compound, for example. As a result, the retardation layer can be a layer having extremely excellent stability without being affected by temperature change.

The liquid crystalline monomer may be, for example, a trade name LC242 manufactured by BASF corporation, a trade name E7 manufactured by Merck corporation, or a trade name LC-Sillicon-CC3767 manufactured by Wacker-Chem corporation. These liquid crystalline monomers may be used alone or in combination of 2 or more.

The temperature range in which the liquid crystalline monomer exhibits liquid crystallinity varies depending on the type thereof. Specifically, the temperature range is preferably 40 to 120 ℃, more preferably 50 to 100 ℃, and most preferably 60 to 90 ℃.

The liquid crystal cured layer can be set so as to function optimally as a λ/4 plate. In other words, the thickness can be set so that desired optical characteristics can be obtained. The thickness of the retardation layer is preferably 0.5 to 10 μm, more preferably 0.5 to 8 μm, and particularly preferably 0.5 to 5 μm.

As a method for producing a film which exhibits optical anisotropy by coating-alignment of a liquid crystal composition, any appropriate method can be employed. Examples thereof include: a method of forming a cured liquid crystal layer by applying an alignment treatment to the surface of a substrate film such as a polyethylene terephthalate film and applying a coating liquid containing the liquid crystal composition to the surface. The coating liquid may contain a polymerization initiator, a crosslinking agent, a surfactant, a solvent, and the like. As the alignment treatment, any appropriate alignment treatment may be adopted. Specifically, mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment may be mentioned.

Specific examples of the mechanical orientation treatment include rubbing treatment and stretching treatment. Specific examples of the physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. Specific examples of the chemical alignment treatment include oblique vapor deposition and photo-alignment treatment. Preferably by rubbing. The alignment treatment may be performed directly on the surface of the base film, or may be performed on an arbitrary appropriate alignment film (typically, a silane coupling agent layer, a polyvinyl alcohol layer, or a polyimide layer) formed on the base film. When the rubbing treatment is performed, it is preferable to perform the rubbing treatment directly on the surface of the base film.

The orientation direction of the orientation treatment may be set according to the desired angle. Since the liquid crystal material can be aligned in accordance with the alignment direction of the base film by performing the alignment treatment, the slow axis of the formed cured liquid crystal layer is substantially the same as the alignment direction of the base film. Therefore, for example, in the case where the polarizing plate 32 (the first polarizing plate 32') (long shape) has an absorption axis in the longitudinal direction thereof, the orientation treatment is performed in a direction having an angle of approximately 135 ° with respect to the longitudinal direction of the substrate (long shape). By forming the cured liquid crystal layer in this way, the polarizer 32 (first polarizer 32') (polarizing plate) and the λ/4 plate 34 can be continuously laminated by a roll-to-roll method. As a result, the manufacturing process can be significantly shortened.

[ lambda/2 plate 54]

As the λ/2 plate 54 used in the polarizing plate groups according to embodiments 3 and 4 of the present invention, a retardation film made of the same material as the λ/4 plate 34 can be used. The λ/2 plate and the λ/4 plate may be formed of the same material, or may be formed of different materials.

From the viewpoint of positive wavelength dispersibility, thinning, and ease of adjustment of the retardation value, it is preferable to use a film exhibiting optical anisotropy by coating-alignment of a polycarbonate resin film or a liquid crystalline compound as in the case of a λ/4 plate.

In the present invention, the phase difference value Re of the λ/2 plate is 200nm to 300nm at a measurement wavelength of 590 nm. Further, the Nz coefficient of the λ/2 plate is preferably in the range of 0.8 to 1.2. More preferably 0.95 to 1.05.

When a film exhibiting optical anisotropy by coating-alignment of a liquid crystalline compound is used for a lambda/2 plate, the thickness of the retardation layer is preferably 0.5 to 20 μm, more preferably 0.5 to 16 μm, and particularly preferably 0.5 to 8 μm.

As a film which exhibits optical anisotropy by application-alignment of a liquid crystal composition, for example, in the case where the second polarizing plate 52' (long) has an absorption axis in its longitudinal direction, alignment treatment is performed in a direction having an angle of approximately 135 ° with respect to the longitudinal direction of the substrate (long). By forming the liquid crystal cured layer in this manner, the second polarizer 52' (polarizing plate) and the λ/2 plate 54 can be continuously laminated by a roll-to-roll method. As a result, the manufacturing process can be significantly shortened.

[ Positive C plates 35, 55]

As used herein, a positive C plate means a plate having n_xAnd n_yAre substantially equal to each otherA retardation film having positive uniaxiality and an optical axis in the film linear direction. If expressed as a refractive index, is n_x≈n_y＜n_zA retardation film having the relationship (2).

The positive C-

plate

35, 55 preferably has an in-plane retardation Re of 20nm or less, more preferably 10nm or less. Further, the retardation value Rth in the thickness direction is preferably from-50 nm to-150 nm. More preferably-70 nm to-120 nm.

The material and form of the positive C-

plate

35, 55 are not particularly limited as long as they have the above optical characteristics. For example, a retardation film formed of a birefringent polymer film, a retardation film having a retardation layer formed by coating or transferring a low molecular or high molecular liquid crystalline compound on a transparent support, or the like can be used. Alternatively, the layers may be stacked and used.

The retardation film having the above optical properties and formed of a birefringent polymer film can be easily formed by a method of applying a predetermined tension while heating after laminating a heat-shrinkable film and stretching the polymer film in the thickness direction of the film, or a method of applying a vinylcarbazole polymer and then drying. Examples of the retardation layer made of a liquid crystalline compound having the above optical properties include a cholesteric discotic liquid crystalline compound containing a chiral structural unit and a composition in which the helical axis of the compound is oriented substantially perpendicular to the substrate and then the compound is immobilized; a rod-like liquid crystal compound having positive refractive index anisotropy, a layer formed by aligning the composition substantially perpendicularly to the substrate and fixing the aligned composition, and the like. The rod-like liquid crystal compound may be a low molecular compound or a high molecular compound. Further, the retardation layer exhibiting the optical characteristics may be constituted by one retardation layer, or may be constituted by laminating a plurality of retardation layers. The retardation layer may be configured such that the entire laminate of the support and the retardation layer satisfies the above optical properties. As the rod-like liquid crystal compound to be used, a liquid crystal compound which is in a nematic liquid crystal phase, a smectic liquid crystal phase, or a lyotropic liquid crystal phase state in a temperature range in which alignment is fixed is suitably used. It is preferable that a liquid crystal showing smectic A and B phases be obtained in which the liquid crystal is vertically aligned uniformly without fluctuation. The birefringence of these phases is larger than that of the nematic liquid crystal phase, and is also preferable in that the film thickness can be reduced. In particular, in the presence of an additive, a composition containing the additive and a rod-like liquid crystalline compound that is brought into the liquid crystal state in an appropriate alignment temperature range is preferably used to form a layer.

As the rod-like liquid crystalline compound, azomethines, azoxides, cyanobiphenyls, cyanophenyl esters, benzoates, phenyl cyclohexanoates, cyanophenylcyclohexanes, cyano-substituted phenyl pyrimidines, alkoxy-substituted phenyl pyrimidines, phenyl dioxanes, tolans, and alkenylcyclohexylbenzonitrile are preferably used. Not only the above low-molecular liquid crystalline molecules but also high-molecular liquid crystalline molecules may be used. Among liquid crystal molecules, molecules having a partial structure capable of undergoing polymerization or crosslinking reaction by active light, electron beam, heat, or the like are suitably used. The number of the local structures is 1-6, preferably 1-3.

When the retardation layer is formed by fixing the rod-like liquid crystalline compound in an aligned state, it is preferable to use a retardation layer formed by substantially vertically aligning the rod-like liquid crystalline compound and fixing the rod-like liquid crystalline compound in this state. The term "substantially perpendicular" means that the angle formed by the film surface and the director of the rod-like liquid crystalline compound is in the range of 70 ° to 90 °. These liquid crystalline compounds may be aligned in an oblique direction, or may be aligned in a state in which the tilt angle is gradually changed (hybrid alignment). In the case of oblique orientation or hybrid orientation, the average tilt angle is also preferably 70 ° to 90 °, more preferably 80 ° to 90 °, and most preferably 85 ° to 90 °.

The retardation layer formed of the rod-like liquid crystalline compound can be formed by applying a coating liquid containing the rod-like liquid crystalline compound, and if necessary, the following polymerization initiator, air interface vertical alignment agent, and other additives onto a vertical alignment film formed on a support, and performing vertical alignment to fix the aligned state. When the retardation layer is formed on a temporary support, the retardation layer may be formed by transferring the retardation layer onto a support. Further, the retardation layer exhibiting the optical characteristics may be constituted not only by one retardation layer, but also by laminating a plurality of retardation layers. The retardation layer may be configured such that the entire laminate of the support and the retardation layer satisfies the above optical properties.

In the present invention, the front C plate layer formed of the liquid crystalline compound may be formed by being superimposed on the λ/4 plate 34 or the λ/2 plate 54.

The 2

positive C plates

35 and 55 used in the present invention preferably have substantially the same phase difference in the thickness direction. In the present invention, the term "substantially equal" means that the difference in the retardation values in the thickness direction is 20nm or less.

[ Brightness enhancement film 61]

The brightness enhancement film 61 is also called a reflective polarizing plate, and a polarization conversion element having a function of separating outgoing light from a light source (backlight) into transmission polarized light and reflection polarized light or scattering polarized light may be used. As described above, by disposing the brightness enhancement film 61 on the polarizing plate 50, it is possible to utilize the return light which is the reflected polarized light or the scattered polarized light, and it is possible to improve the emission efficiency of the linearly polarized light emitted from the polarizing plate 50.

The brightness enhancing film 61 can be, for example, an anisotropic reflective polarizer. An example of the anisotropic reflective polarizing plate is an anisotropic multiple film which transmits linearly polarized light in one vibration direction and reflects linearly polarized light in the other vibration direction, and a specific example thereof is DBEF manufactured by 3M (japanese patent application laid-open No. 4-268505, etc.). Another example of the anisotropic reflective polarizing plate is a composite of a cholesteric liquid crystal layer and a λ/4 plate, and a specific example thereof is PCF manufactured by Nidong electric (Japanese patent laid-open No. 11-231130, etc.). Yet another example of an anisotropic reflective polarizer is a reflective grid polarizer, specific examples of which are: a metal-grid reflective polarizing plate (for example, U.S. Pat. No. 6288840) in which a metal is finely processed to emit a reflected polarized light even in the visible light region, and a film obtained by adding metal fine particles to a polymer matrix and then stretching the polymer matrix (japanese patent laid-open No. 8-184701).

An optical layer such as a hard coat layer, an antiglare layer, a light diffusion layer, a retardation layer having a phase difference value of 1/4 wavelength may be provided on the surface of the brightness enhancement film 61 opposite to the polarizing plate 50. By forming the optical layer, the adhesiveness of the backlight tape and the uniformity of a displayed image can be improved. The thickness of the brightness enhancement film 61 may be about 10 to 100 μm, but from the viewpoint of making the polarizing plate thinner, it is preferably 10 to 50 μm, and more preferably 10 to 30 μm.

[ bonding of layers ]

It is preferable to provide any appropriate pressure-sensitive adhesive layer or adhesive layer between the respective members constituting the polarizing plate of the present invention. For example, in order to attach the polarizing plate to the liquid crystal cell, an adhesive layer is preferably provided on the surface of the polarizing plate. In embodiment 1 and embodiment 2, for example, an adhesive layer may be provided on the outer side of the λ/4 plate 34 and an adhesive layer may be provided on the outer side of the protective film 51 b. In embodiments 3 and 4, for example, an adhesive layer may be provided on the outer side of the λ/4 plate 34 and an adhesive layer may be provided on the outer side of the λ/2 plate 54.

Examples of the adhesive for forming the adhesive layer include an aqueous adhesive and an active energy ray-curable adhesive which is cured by irradiation with ultraviolet rays or electron beams. Examples of the active energy ray-curable adhesive include a composition containing a radical polymerizable compound such as an acrylic compound and a composition containing a cation polymerizable compound such as an epoxy compound. These compositions preferably each contain a radical polymerization initiator, or a cationic polymerization initiator. As the binder, a binder containing an acrylic resin (acrylic binder) is preferable.

[ liquid Crystal cell 60]

The liquid crystal cell has a pair of substrates, and a liquid crystal layer as a display medium sandwiched between the substrates. A color filter and a black matrix are provided on one substrate (color filter substrate). On the other substrate (active matrix substrate), a switching element (typically, TFT) for controlling electro-optical characteristics of liquid crystal, a scanning line for applying a gate signal to the switching element, a signal line for applying a source signal to the switching element, and a pixel electrode are provided.

Note that the color filter may be provided on the active matrix substrate side. The interval (cell gap) between the substrates is controlled by spacers. An alignment film made of, for example, polyimide is provided on the side in contact with the liquid crystal layer between the substrates.

As a driving mode of the liquid crystal cell for disposing the polarizing plate groups of embodiment 1 and embodiment 3 of the present invention, an IPS (In-Plane Switching) mode having an In-Plane retardation value of 100 to 200nm at a wavelength of 590nm can be used. By providing the liquid crystal cell itself with an in-plane retardation value close to λ/4 wavelength, the circularly polarizing plate can be arranged as the viewing-side polarizing plate, and reflection of external light can be greatly reduced.

The in-plane retardation of the liquid crystal cell can be adjusted to 100nm to 200nm at a wavelength of 590nm by adjusting the thickness of the liquid crystal in the liquid crystal cell. For example, a liquid crystal cell having a desired in-plane retardation value can be manufactured by adjusting the thickness of the liquid crystal cell to about 1 to 2 μm.

As a driving mode of the liquid crystal cell for disposing the polarizing plate groups of embodiment 2 and embodiment 4 of the present invention, an IPS (In-Plane Switching) mode having an In-Plane retardation value of 400 to 500nm at a wavelength of 590nm can be employed. As described above, the liquid crystal cell itself has an in-plane retardation value close to 3 λ/4 wavelength, and thus the circularly polarizing plate can be arranged as the viewing-side polarizing plate, and reflection of external light can be greatly reduced.

The in-plane retardation of the liquid crystal cell can be adjusted to 400nm to 500nm at a wavelength of 590nm by adjusting the thickness of the liquid crystal in the liquid crystal cell. For example, a liquid crystal cell having a desired in-plane retardation value can be manufactured by adjusting the thickness of the liquid crystal cell to about 1 to 6 μm.

[ liquid Crystal display device ]

The liquid crystal display device of the present invention includes the polarizing plate group of the present invention and the liquid crystal cell. The liquid crystal display device of the present invention is particularly excellent in outdoor visibility even when the external light is strong, and therefore is suitably used for liquid crystal display devices for medium-to small-sized applications. For example, the liquid crystal display device is suitable for a case where the size of the liquid crystal display device is 15 inches or less diagonally.

The axis structure of each member in the liquid crystal display device according to embodiment 1 of the present invention will be described with reference to fig. 3.

For convenience of explanation, the initial alignment direction of the liquid crystal cell used in the present invention is defined as 0 °, and the counterclockwise rotation angle when the rear-side polarizing plate is viewed from the viewing-side polarizing plate is defined as positive. The slow axis of the λ/4 plate 34 is arranged at substantially-90 ° with respect to the initial orientation direction. The absorption axis of the viewing-side polarizing plate is arranged at substantially-45 ° with respect to the initial orientation direction, and the absorption axis of the rear-side polarizing plate is arranged at substantially 45 ° with respect to the initial orientation direction. Here, when the expression is approximately several °, the expression is within a range of ± 5 ° of the value, and preferably within a range of ± 2 ° of the value.

Next, the axis structure of each member in the liquid crystal display device according to embodiment 2 of the present invention will be described with reference to fig. 4.

The slow axis of the λ/4 plate 34 is arranged at substantially 0 ° with respect to the initial alignment direction of the liquid crystal cell. The absorption axis of the viewing-side polarizing plate is arranged at substantially 45 ° with respect to the initial orientation direction, and the absorption axis of the back-side polarizing plate is arranged at substantially 135 ° with respect to the initial orientation direction. Here, when the expression is approximately several °, the expression is within a range of ± 5 ° of the value, and preferably within a range of ± 2 ° of the value.

Next, the axis structure of each member in the liquid crystal display device according to embodiment 3 of the present invention will be described with reference to fig. 5.

The slow axis of the λ/4 plate 34 is arranged at substantially-90 ° with respect to the initial alignment direction of the liquid crystal cell, and the slow axis of the λ/2 plate 54 is arranged at substantially 0 ° with respect to the initial alignment direction. The absorption axis of the viewing-side polarizing plate is arranged at substantially-45 ° with respect to the initial orientation direction, and the absorption axis of the back-side polarizing plate is arranged at substantially-45 ° with respect to the initial orientation direction. Here, when the expression is approximately several °, the expression is within a range of ± 5 ° of the value, and preferably within a range of ± 2 ° of the value.

Next, the axis structure of each member in the liquid crystal display device according to embodiment 4 of the present invention will be described with reference to fig. 6.

The slow axis of the λ/4 plate 34 is arranged substantially 0 ° with respect to the initial alignment direction of the liquid crystal cell, and the slow axis of the λ/2 plate 54 is arranged substantially 90 ° with respect to the initial alignment direction. The absorption axis of the viewing-side polarizing plate is arranged at substantially 45 ° with respect to the initial orientation direction, and the absorption axis of the back-side polarizing plate is arranged at substantially 45 ° with respect to the initial orientation direction. Here, when the expression is approximately several °, the expression is within a range of ± 5 ° of the value, and preferably within a range of ± 2 ° of the value.

In the present invention, the initial alignment direction of the liquid crystal cell means the alignment direction of the liquid crystal molecules in an initial state in which no driving voltage is applied to the liquid crystal cell, and the initial alignment angle is preferably an angle of substantially 45 ° with respect to the long side of the liquid crystal cell.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the examples, parts and% indicating contents or amounts used are on a weight basis unless otherwise specified. In addition, the counterclockwise rotation is set to be positive with respect to the angle. The measurement of each physical property in the following examples was performed by the following method.

(1) Measurement of thickness:

the measurement was carried out using a digital micrometer "MH-15M" manufactured by Nikon K.K.

(2) Measurement of in-plane retardation and thickness-direction retardation:

the in-plane retardation and the retardation in the thickness direction at each wavelength were measured at a temperature of 23 ℃ using a phase difference meter "KOBRA (registered trademark) -WPR" manufactured by prince instruments co.

(3) Measurement of degree of polarization and monomer transmittance of polarizing plate:

a spectrophotometer with an integrating sphere ("V7100" manufactured by japan spectrographic corporation, 2 degree field of view; c illuminant ] was measured.

(4) Measurement of shrinkage force of polarizing plate

The polarizing plate was cut into a width of 2mm and a length of 50mm by using a SUPERCUTTER (manufactured by Yamada seiki Kogyo Co., Ltd.) so that the direction of the shrinkage force (the absorption axis direction of the polarizing plate) was a long side. The resulting strip-shaped small piece was used as a test piece. The shrinkage force of the test piece was measured using a thermomechanical analyzer (model TMA/6100, manufactured by SII Nanotechnology Co., Ltd.). The measurement was performed in a constant dimension mode, and the inter-chuck distance was set to 10 mm. The test piece was left in a room of 23 ℃ and 55% for 24 hours or more, and then the temperature in the sample room was set from 23 ℃ to 80 ℃ for 1 minute, and after the temperature was raised, the temperature in the sample room was set to be maintained at 80 ℃. After the temperature was raised, the test piece was left to stand for a further 4 hours, and then the shrinkage force in the longitudinal direction of the test piece was measured at 80 ℃.

In this measurement, the static load was set to 0mN, and a SUS probe was used as a holder.

Production example 1 production of polarizing plate

A polyvinyl alcohol film (average polymerization degree of about 2400, saponification degree of 99.9 mol% or more) having a thickness of 30 μm was uniaxially stretched to about 4 times by dry stretching, and then immersed in pure water at 40 ℃ for 40 seconds while being kept in a taut state, and then immersed in an aqueous solution having a weight ratio of iodine/potassium iodide/water of 0.052/5.7/100 at 28 ℃ for 30 seconds, thereby carrying out dyeing treatment. Then, the plate was immersed in an aqueous solution of potassium iodide/boric acid/water at a weight ratio of 11.0/6.2/100 at 70 ℃ for 120 seconds. Then, the substrate was washed with pure water at 8 ℃ for 15 seconds, and then dried at 60 ℃ for 50 seconds and then at 75 ℃ for 20 seconds while being held under a tension of 300N, thereby obtaining an absorption-type polarizing plate having a thickness of 12 μm and an iodine orientation adsorbed in a polyvinyl alcohol film. The shrinkage force of the obtained polarizing plate was measured, and it was found to be 2.0N/2 mm.

Production example 2 preparation of aqueous adhesive

To 100 parts by weight of water was dissolved 3 parts by weight of carboxyl-modified polyvinyl alcohol [ trade name "KL-318" obtained from KURARAY corporation ], and 1.5 parts by weight of a polyamide epoxy additive (trade name "Sumirez Resin (registered trademark) 650 (30)" obtained from tiangang chemical industries co., ltd., solid content concentration 30% by weight) as a water-soluble epoxy Resin was added to the aqueous solution to prepare a water-based adhesive.

[ adhesive A, B ]

The following 2 adhesives were prepared.

Adhesive A: sheet-like adhesive having a thickness of 25 μm ("P-3132" available from LINTEC Co., Ltd.)

And (3) adhesive B: sheet adhesive having a thickness of 5 μm ("NCF # L2" manufactured by LINTEC corporation)

[ protective film A, B, C, D ]

The following 4 kinds of protective films were prepared.

And (3) protecting the film A: a triacetyl cellulose film with a hard coat layer manufactured by konica minolta corporation; 25KCHCN-TC (thickness 32 μm)

And (3) a protective film B: a triacetyl cellulose film manufactured by Konika Mingta; KC2UA (thickness 25 μm)

And (3) a protective film C: a cyclic polyolefin resin film manufactured by japan ZEON corporation; ZF 14-013 (thickness 13 μm, in-plane retardation at wavelength 590nm of 0.8nm, thickness-direction retardation at wavelength 590nm of 3.4nm)

And (3) a protective film D: an antireflection film made of a triacetyl cellulose resin manufactured by TOPPAN TOMOEGAWA OPTICALPRODUCTS; 40KSPLR (thickness 44 μm, Y value 1.1% according to JIS-Z8701-1982)

[ Brightness enhancement film A ]

The following brightness enhancement films were prepared.

A brightness enhancement film A: brightness enhancing Film 26 μ M thick (trade name "Advanced Polarized Film, Version 3" manufactured by 3M)

[ production of λ/4 plate 1]

After a polyvinyl alcohol film (thickness: 0.1 μm) was formed on the surface of the base film (triacetyl cellulose film, thickness: 80 μm), the surface of the polyvinyl alcohol film was rubbed using a rubbing cloth in a direction of-45 ° with respect to the longitudinal direction of the substrate, thereby producing a base film provided with an alignment film.

Next, 10g of a polymerizable liquid crystal (product name: paliocolor lc242, manufactured by BASF) exhibiting a nematic liquid crystal phase and 0.5g of a photopolymerization initiator (product name: Irgacure (registered trademark) 907, manufactured by Ciba Specialty Chemicals, containing 1% of a benzotriazole-based ultraviolet absorber) for the polymerizable liquid crystal compound were dissolved in 40g of toluene to prepare a coating liquid. Then, the coating liquid was applied to the surface of the alignment substrate obtained above by a bar coater, and then heated and dried at 90 ℃ for 2 minutes, thereby aligning the liquid crystal. The thus-formed liquid crystal layer was irradiated with 20mJ/cm using a metal halide lamp²The liquid crystal layer is cured, thereby forming a retardation layer on the substrate. The thickness of the resulting retardation layer was 1 μm, and the in-plane retardation value was 139.8nm at a wavelength of 590 nm.

[ preparation of λ/4 plate 2]

A resin FILM obtained by hydrogenating a ring-opened polymer of a norbornene-based monomer ("ZEONOR FILM (registered trademark)" manufactured by japan ZEON corporation) was uniaxially stretched in the longitudinal direction. The thickness of the resulting retardation film was 18 μm, and the in-plane retardation value was 137.2nm at a wavelength of 590 nm.

[ preparation of λ/2 plate 1]

Next, 10g of a polymerizable liquid crystal (product name: paliocolor lc242, manufactured by BASF) exhibiting a nematic liquid crystal phase and 0.5g of a photopolymerization initiator (product name: Irgacure (registered trademark) 907, manufactured by Ciba Specialty Chemicals, containing 1% of a benzotriazole-based ultraviolet absorber) for the polymerizable liquid crystal compound were dissolved in 40g of toluene to prepare a coating liquid. Then, by bar coatingThe coating liquid was applied to the surface of the alignment substrate obtained above, and then heated and dried at 90 ℃ for 2 minutes, thereby aligning the liquid crystal. The thus-formed liquid crystal layer was irradiated with 20mJ/cm using a metal halide lamp²The liquid crystal layer is cured, thereby forming a retardation layer on the substrate. The thickness of the resulting retardation layer was 2 μm, and the in-plane retardation value was 258.6nm at a wavelength of 590 nm.

[ preparation of λ/2 plate 2]

A resin FILM obtained by hydrogenating a ring-opened polymer of a norbornene-based monomer ("ZEONOR FILM (registered trademark)" manufactured by japan ZEON corporation) was uniaxially stretched in the longitudinal direction. The thickness of the resulting retardation film was 39 μm, and the in-plane retardation value was 265.4nm at a wavelength of 590 nm.

[ production of Positive C plate 1]

A commercially available vertical alignment film (JALS-204R, manufactured by Nippon synthetic rubber Co., Ltd.) was diluted 1: 1 with methyl ethyl ketone and applied to the surface (coating weight: 2.4ml/m, thickness: 80 μm) of a base film (triacetyl cellulose film) by a wire bar coater²). Immediately dried with hot air at 120 ℃ for 120 seconds.

Then, 3.8g of the following rod-like liquid crystal compound, 0.06g of a photopolymerization initiator (Irgacure (registered trademark) 907, manufactured by Ciba-Geigy Co., Ltd.), 0.02g of a sensitizer (KAYACURE (registered trademark) DETX, manufactured by Nippon Kayaku Co., Ltd.), and 0.002g of the following air interface side homeotropism agent were dissolved in 9.2g of methyl ethyl ketone to prepare a solution. The solution was applied to the alignment film side of the film on which the alignment film was formed by a wire bar, and heated at 100 ℃ for 2 minutes to align the rod-like liquid crystal compound. Then, at 80 ℃ using 120W/cm²The rod-like liquid crystal compound was crosslinked by UV irradiation for 20 seconds using a high-pressure mercury lamp, and then left to cool to room temperature, thereby producing a retardation layer having positive C plate characteristics. The thickness of the resulting retardation layer was 0.6. mu.m, and the retardation value in the thickness direction at a wavelength of 590nm was-109.4 nm.

Rod-like liquid crystal compound

Air interface side homeotropic alignment agent:

an example of the compound (II-4) described in Japanese patent application No. 2003-119959

[ production of C plates 2 to 3]

Positive C plates 2-3 are fabricated in the same manner as the positive C plate 1. By adjusting the thickness, the phase difference value is set to a desired phase difference value.

The positive C plate 2 has a retardation value Rth (590) in the thickness direction of-91.2 nm,

the positive C plate 3 has a retardation value Rth (590) in the thickness direction of-69.1 nm,

[ production of polarizing plate A ]

The protective film a was saponified, and the surface of the protective film C to be bonded to the polarizing plate was corona-treated. The polarizing plate a was obtained by bonding the protective film a, the polarizer, and the protective film C with a water-based adhesive so that the triacetylcellulose surface of the protective film a and the corona-treated surface of the protective film C were the bonding surfaces with the polarizer.

[ production of polarizing plate B ]

The protective film B was saponified, and the surface of the protective film C to be bonded to the polarizing plate was corona-treated. The polarizing plate was obtained by bonding the protective film B, the polarizer, and the protective film C with a water-based adhesive so that the surfaces of the protective film B and the protective film C subjected to the corona treatment were the surfaces to be bonded to the polarizer. The adhesive B is bonded to the protective film B side of the polarizing plate B. At this time, the contact surface between the protective film B and the adhesive B is subjected to corona treatment. Finally, the brightness enhancement film a was attached to the adhesive B side of the polarizing plate to obtain a polarizing plate B.

[ production of pseudo liquid Crystal cell ]

The production of the pseudo liquid crystal cell a in embodiment 1 or embodiment 3 of the present invention will be described. 2 pieces of alkali-free glass manufactured by Corning corporation were prepared: eagle XG (thickness 0.7mm, length 157 mm. times. width 98 mm) was attached to the adhesive B. At this time, the bonding surface between the glass and the adhesive is subjected to corona treatment. Next, the previously prepared λ/4 plate 1 was bonded to the B-side surface of the adhesive of one glass sheet. At this time, the λ/4 plate 1 and the adhesive B face were also subjected to corona treatment. Finally, the surface of the λ/4 plate 1 of the glass to which the λ/4 plate 1 is bonded to the surface of the other glass with the adhesive B, thereby producing a pseudo liquid crystal cell a. At this time, the surface of the λ/4 plate 1 to be bonded to the adhesive B was subjected to corona treatment. The plate was manufactured so that the slow axis direction of the λ/4 plate 1 was-45 ° with the longitudinal direction of the glass set to 0 °.

The initial alignment direction of the pseudo liquid crystal cell a in embodiment 1 or 3 of the present invention is assumed to be 45 ° with respect to the longitudinal direction of the glass, and the pseudo liquid crystal cell a is assumed to be a liquid crystal cell when a driving voltage is applied (in a white display).

Next, the production of the pseudo liquid crystal cell B in embodiment 2 or embodiment 4 of the present invention will be described. 2 pieces of alkali-free glass manufactured by Corning corporation were prepared: EagleXG (thickness 0.7mm, length 157 mm. times. width 98 mm) was attached to the adhesive B. At this time, the bonding surface between the glass and the adhesive is subjected to corona treatment. Next, the previously prepared λ/4 plate 1 was bonded to the B-side surface of the 2-sheet glass adhesive. The lambda/4 plate 1 and the adhesive B side were corona treated at this time. Further, an adhesive B was bonded to the surface 1 of the 2-glass λ/4 plate. The lambda/4 plate 1 and the adhesive B side were also corona treated at this time. For one piece of glass, a lambda/4 plate 1 was further attached to the adhesive B side. The lambda/4 plate 1 and the adhesive B side were also corona treated at this time.

Finally, the λ/4 plate 1 side of one glass sheet was bonded to the adhesive B side of the other glass sheet to produce a pseudo liquid crystal cell B. At this time, the surface of the λ/4 plate 1 to be bonded to the adhesive B was subjected to corona treatment.

The retardation axis direction of all λ/4 plates 1 was set to 45 ° when the longitudinal direction of the glass was set to 0 °.

The liquid crystal cell B in embodiment 2 or 4 of the present invention is assumed to have an initial alignment direction of-45 ° with respect to the longitudinal direction of the glass, and the liquid crystal cell B is assumed to be a liquid crystal cell when a driving voltage is applied (during white display).

Then, using High MackieBlue (MO-150-MC-BL) manufactured by Zebra corporation, a drawing (portrait of duo a dream (cat type robot entered in duo a dream of rattan F.

[ backlight ]

The backlight was obtained by taking out a liquid crystal panel from Nexus7 (registered trademark) manufactured by Google inc, and lighting only the backlight.

[ example 1-1]

(production of side polarizing plate for visual recognition 1-1)

The adhesive B was attached to the surface of the protective film C of the polarizing plate a. At this time, the surface of the protective film C and the surface of the adhesive B to be bonded are subjected to corona treatment. Next, the λ/4 plate 1 was laminated on the adhesive B surface of the polarizing plate a thus produced. At this time, the contact surface between the adhesive B and the λ/4 plate 1 was subjected to corona treatment.

The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/4 plate 1 was 45 ° (the slow axis of the λ/4 plate 1 was arranged so as to be rotated 45 ° counterclockwise with respect to the absorption axis of the polarizing plate when the protective film C was viewed from the protective film a).

Further, an adhesive B was bonded to the surface of the lambda/4 plate 1 of the polarizing plate A. At this time, the surface of the polarizing plate a, which is λ/4 plate 1, and the surface to be bonded with the adhesive B are also subjected to corona treatment. Next, the positive C plate 1 was bonded to the adhesive B surface of the polarizing plate a. At this time, the surface of the adhesive B and the surface of the front C plate 1 to be bonded are also subjected to corona treatment.

Finally, adhesive a was attached to the front C plate 1 side of polarizing plate a. At this time, the surface of the alignment C plate 1 and the bonding surface of the adhesive a are also subjected to corona treatment. This produces a viewing-side polarizing plate 1-1.

(preparation of Back side polarization 1-1)

The adhesive a was attached to the surface of the protective film C of the polarizing plate B to prepare a rear-side polarizing plate 1-1. At this time, the surface of the protective film C and the surface of the adhesive a to be bonded are subjected to corona treatment.

The thus prepared polarizing plate 1-1 on the viewing side and the polarizing plate 1-1 on the back side were cut to a size of 155mm in the vertical direction by 96mm in the horizontal direction. At this time, the protective film a of the viewing-side polarizing plate 1-1 is cut so that the absorption axis of the viewing-side polarizing plate is parallel to the short side direction when viewed from above, and the protective film B of the back-side polarizing plate 1-1 is cut so that the absorption axis of the back-side polarizing plate 1-1 is parallel to the long side direction when viewed from above.

A viewing side polarizing plate 1-1 is bonded to the glass surface of the pseudo liquid crystal cell A on which a picture is drawn, and a back side polarizing plate 1-1 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 3 (b).

The pseudo liquid crystal panel thus produced was placed on the backlight thus produced, and it was confirmed whether or not a picture could be visually recognized. The visibility was confirmed under an external light, and as a result, the visibility was good even at 7500 Lux.

[ examples 1-2]

A pseudo liquid crystal panel was produced in the same manner as in example 1-1, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 1 to 3]

A pseudo liquid crystal panel was produced in the same manner as in example 1-1, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 1 to 4]

A pseudo liquid crystal panel was produced in the same manner as in example 1-1, except that the protective film a of the viewing-side polarizing plate 1-1 was changed to the protective film D.

The pseudo liquid crystal panel thus produced was placed on the backlight thus produced, and it was confirmed whether or not a picture could be visually recognized. The visibility was confirmed under external light, and as a result, the visibility was good even at 10000 Lux.

[ examples 1 to 5]

A pseudo liquid crystal panel was produced in the same manner as in examples 1 to 4, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 1 to 6]

A pseudo liquid crystal panel was produced in the same manner as in examples 1 to 4, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 1 to 7]

(production of side polarizing plate for visual recognition 1-2)

The adhesive B was attached to the surface of the protective film C of the polarizing plate a. At this time, the surface of the protective film C and the surface of the adhesive B to be bonded are subjected to corona treatment. Next, the positive C plate 1 was bonded to the adhesive B surface of the produced polarizing plate a. At this time, the surface of the adhesive B and the surface of the front C plate 1 to be bonded are also subjected to corona treatment. Further, an adhesive B was attached to the front C plate 1 side of the polarizing plate a. At this time, the surface of the polarizing plate a to which the front C plate 1 and the adhesive B are bonded is also subjected to corona treatment. Next, the λ/4 plate 1 was bonded to the adhesive B surface of the polarizing plate a. At this time, the contact surface between the adhesive B and the λ/4 plate 1 was subjected to corona treatment. The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/4 plate 1 was 45 ° (the slow axis of the λ/4 plate 1 was arranged so as to be rotated 45 ° counterclockwise with respect to the absorption axis of the polarizing plate when the protective film C was viewed from the protective film a).

Finally, the adhesive a was attached to the λ/4 plate 1 side of the polarizing plate a. At this time, the surface of the λ/4 plate 1 to be bonded to the adhesive A was also subjected to corona treatment. This produces a viewing-side polarizing plate 1-2.

The thus prepared polarizing plate 1-2 for viewing side and the polarizing plate 1-1 for back side were cut to a size of 155mm in vertical direction by 96mm in horizontal direction. At this time, the protective film a of the viewing-side polarizing plate 1-2 is cut so that the absorption axis of the viewing-side polarizing plate is parallel to the short side direction when viewed from above, and the absorption axis of the back-side polarizing plate 1-1 is cut so that the absorption axis is parallel to the long side direction when viewed from above the protective film B of the back-side polarizing plate 1-1.

A viewing side polarizing plate 1-2 is bonded to the glass surface of the pseudo liquid crystal cell A on which a picture is drawn, and a back side polarizing plate 1-1 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 3 (b).

[ examples 1 to 8]

A pseudo liquid crystal panel was produced in the same manner as in examples 1 to 7, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 1 to 9]

A pseudo liquid crystal panel was produced in the same manner as in examples 1 to 7, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 1 to 10]

A pseudo liquid crystal panel was produced in the same manner as in examples 1 to 7, except that the protective film a of the viewing-side polarizing plate 1-2 was changed to the protective film D.

[ examples 1 to 11]

A pseudo liquid crystal panel was produced in the same manner as in examples 1 to 10, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 1 to 12]

A pseudo liquid crystal panel was produced in the same manner as in examples 1 to 10, except that the positive C plate 1 was changed to the positive C plate 3.

Examples 1-13 to 1-24

A pseudo liquid crystal panel was produced in the same manner as in examples 1-1 to 1-12 except that the λ/4 plate 1 was changed to the λ/4 plate 2. The correspondence between the numbers of the respective examples is shown in table 1 below.

[ Table 1]

The pseudo liquid crystal panel thus produced was placed on the backlight thus produced, and it was confirmed whether or not a picture could be visually recognized. The visibility was confirmed under external light, and as a result, the visibility was good even at 10000Lux in all of the pseudo liquid crystal panels.

Comparative example 1

The upper and lower polarizing plates were peeled from a Nexus7 (registered trademark) liquid crystal panel manufactured by Google inc, and the in-plane retardation of the liquid crystal cell was measured at a wavelength of 590nm, which was 355 nm. Next, a polarizing plate a was attached to the viewing side of the removed liquid crystal cell via an adhesive a, and a polarizing plate B was attached to the back side of the removed liquid crystal cell via an adhesive a, thereby producing a liquid crystal panel. The liquid crystal panel thus produced was attached to Nexus7, and an image of a picture was displayed on the screen to confirm whether or not the panel was visible under external light. As a result, the visibility significantly decreases at 5000Lux, and the recognition of the image becomes difficult.

[ example 2-1]

(production of side polarizing plate for visual recognition 2-1)

The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/4 plate 1 was-45 ° (the slow axis of the λ/4 plate 1 was arranged so as to be rotated by 45 ° clockwise with respect to the absorption axis of the polarizing plate when the protective film C was viewed from the protective film a).

Finally, adhesive a was attached to the front C plate 1 side of polarizing plate a. At this time, the surface of the alignment C plate 1 and the bonding surface of the adhesive a are also subjected to corona treatment. This produces a viewing-side polarizing plate 2-1.

(production of Back-side polarizing plate 2-1)

The adhesive a was attached to the surface of the protective film C of the polarizing plate B to prepare a rear-side polarizing plate 2-1. At this time, the surface of the protective film C and the surface of the adhesive a to be bonded are subjected to corona treatment.

The thus prepared polarizing plate 2-1 on the viewing side and the polarizing plate 2-1 on the back side were cut to a size of 155mm in the vertical direction by 96mm in the horizontal direction. At this time, the protective film a of the viewing-side polarizing plate 2-1 is cut so that the absorption axis of the viewing-side polarizing plate is parallel to the short side direction when viewed from above, and the absorption axis of the back-side polarizing plate 2-1 is cut so that the absorption axis is parallel to the long side direction when viewed from above the protective film B of the back-side polarizing plate 2-1.

A viewing side polarizing plate 2-1 is bonded to the glass surface of the pseudo liquid crystal cell B on which a picture is drawn, and a back side polarizing plate 2-1 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 4 (b).

[ examples 2-2]

A pseudo liquid crystal panel was produced in the same manner as in example 2-1, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 2 to 3]

A pseudo liquid crystal panel was produced in the same manner as in example 2-1, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 2 to 4]

A pseudo liquid crystal panel was produced in the same manner as in example 2-1, except that the protective film a of the viewing-side polarizing plate 2-1 was changed to the protective film D.

[ examples 2 to 5]

A pseudo liquid crystal panel was produced in the same manner as in examples 2 to 4, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 2 to 6]

A pseudo liquid crystal panel was produced in the same manner as in examples 2 to 4, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 2 to 7]

(production of side polarizing plate for visual recognition 2-2)

The adhesive B was attached to the surface of the protective film C of the polarizing plate a. At this time, the surface of the protective film C and the surface of the adhesive B to be bonded are subjected to corona treatment. Next, the front C plate 1 was laminated on the adhesive B layer of the polarizing plate a thus produced. At this time, the surface of the adhesive B bonded to the front C plate 1 was subjected to corona treatment. Further, an adhesive B was attached to the front C plate 1 side of the polarizing plate a. At this time, the surface of the polarizing plate a to which the front C plate 1 and the adhesive B are bonded is also subjected to corona treatment. Next, the λ/4 plate 1 was bonded to the adhesive B surface of the polarizing plate a. At this time, the surface of the adhesive B and the surface to be bonded of the λ/4 plate 1 were also subjected to corona treatment. The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/4 plate 1 was-45 ° (the slow axis of the λ/4 plate 1 was arranged so as to be rotated by 45 ° clockwise with respect to the absorption axis of the polarizing plate when the protective film C was viewed from the protective film a). Finally, the adhesive a was attached to the λ/4 plate 1 side of the polarizing plate a. At this time, the surface of the λ/4 plate 1 to be bonded to the adhesive A was also subjected to corona treatment. This produces a viewing-side polarizing plate 2-2.

The thus prepared polarizing plate 2-2 for viewing side and the polarizing plate 2-1 for back side were cut to a size of 155mm in vertical direction by 96mm in horizontal direction. At this time, the protective film a of the viewing-side polarizing plate 2-2 is cut so that the absorption axis of the viewing-side polarizing plate is parallel to the short side direction when viewed from above, and the absorption axis of the back-side polarizing plate 2-1 is cut so that the absorption axis is parallel to the long side direction when viewed from above the protective film B of the back-side polarizing plate 2-1.

A viewing side polarizing plate 2-2 is bonded to the glass surface of the pseudo liquid crystal cell B on which a picture is drawn, and a back side polarizing plate 2-1 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 4 (b).

[ examples 2 to 8]

A pseudo liquid crystal panel was produced in the same manner as in examples 2 to 7, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 2 to 9]

A pseudo liquid crystal panel was produced in the same manner as in examples 2 to 7, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 2 to 10]

A pseudo liquid crystal panel was produced in the same manner as in examples 2 to 7, except that the protective film a of the viewing-side polarizing plate 2-2 was changed to the protective film D.

[ examples 2 to 11]

A pseudo liquid crystal panel was produced in the same manner as in examples 2 to 10, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 2 to 12]

A pseudo liquid crystal panel was produced in the same manner as in examples 2 to 10, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 2-13 to 2-24]

A pseudo liquid crystal panel was produced in the same manner as in examples 2-1 to 2-12 except that the λ/4 plate 1 was changed to the λ/4 plate 2. The correspondence between the numbers of the respective examples is shown in table 2 below.

[ Table 2]

[ example 3-1]

(production of side polarizing plate for visual recognition 3-1)

The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/4 plate 1 was 45 ° (the λ/4 plate 1 was disposed so as to be rotated 45 ° counterclockwise with respect to the absorption axis of the polarizing plate when the protective film C was viewed from the protective film a).

Finally, adhesive a was attached to the front C plate 1 side of polarizing plate a. At this time, the surface of the alignment C plate 1 and the bonding surface of the adhesive a are also subjected to corona treatment. This produces a viewing-side polarizing plate 3-1.

(production of Back-side polarizing plate 3-1)

The rear-side polarizing plate 3-1 was produced in the same manner as the viewing-side polarizing plate 3-1 except that the polarizing plate a was changed to the polarizing plate B and the λ/4 plate 1 was changed to the λ/2 plate 1. The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/2 plate 1 was 45 ° (the λ/2 plate 1 was disposed so as to be rotated 45 ° counterclockwise with respect to the absorption axis of the polarizing plate when the protective film B was viewed from the protective film C). The phase difference value in the thickness direction at a wavelength of 590nm was visually recognized to be the same for the positive C-plate of the side polarizing plate and the positive C-plate of the back side polarizing plate.

The thus-prepared polarizing plate 3-1 on the viewing side and the polarizing plate 3-1 on the back side were cut to a size of 155mm in the vertical direction by 96mm in the horizontal direction. At this time, the polarizing plates were cut so that the absorption axes thereof were 90 ° with respect to the longitudinal direction.

A viewing side polarizing plate 3-1 is bonded to the glass surface of the pseudo liquid crystal cell A on which a picture is drawn, and a back side polarizing plate 3-1 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 5 (b).

[ examples 3-2]

A pseudo liquid crystal panel was produced in the same manner as in example 3-1, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 3 to 3]

A pseudo liquid crystal panel was produced in the same manner as in example 3-1, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 3 to 4]

A pseudo liquid crystal panel was produced in the same manner as in example 3-1, except that the protective film a of the viewing-side polarizing plate 3-1 was changed to the protective film D.

[ examples 3 to 5]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 4, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 3 to 6]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 4, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 3 to 7]

(production of Back-side polarizing plate 3-2)

The adhesive B was attached to the surface of the protective film C of the polarizing plate B. At this time, the surface of the protective film C and the surface of the adhesive B to be bonded are subjected to corona treatment. Next, the positive C plate 1 was bonded to the adhesive B surface of the produced polarizing plate B. At this time, the surface of the adhesive B and the surface of the front C plate 1 to be bonded are also subjected to corona treatment. Further, an adhesive B was attached to the front C plate 1 side of the polarizing plate B. At this time, the surface of the polarizing plate B to be bonded to the front C plate 1 and the adhesive B were also subjected to corona treatment. Next, the λ/2 plate 1 was bonded to the adhesive B surface of the polarizing plate B. At this time, the surface of the adhesive B and the surface of the λ/2 plate 1 to be bonded were also subjected to corona treatment. The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/2 plate 1 was 45 ° (the λ/2 plate 1 was disposed so as to be rotated 45 ° counterclockwise with respect to the absorption axis of the polarizing plate when the protective film B was viewed from the protective film C). Finally, the adhesive a was attached to the λ/2 plate 1 side of the polarizing plate B. At this time, the surface of the λ/2 plate 1 to be bonded to the adhesive A was also subjected to corona treatment. The rear-side polarizing plate 3-2 was thus produced. The phase difference value in the thickness direction at a wavelength of 590nm was observed to be the same for the front C-plate of the side polarizing plate 3-1 and the front C-plate of the rear side polarizing plate.

The thus-prepared polarizing plate 3-1 on the viewing side and the polarizing plate 3-2 on the back side were cut to a size of 155mm in the vertical direction by 96mm in the horizontal direction. At this time, the polarizing plates were cut so that the absorption axes thereof were 90 ° with respect to the longitudinal direction.

A viewing side polarizing plate 3-1 is bonded to the glass surface of the pseudo liquid crystal cell A on which a picture is drawn, and a back side polarizing plate 3-2 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 5 (b).

[ examples 3 to 8]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 7, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 3 to 9]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 7, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 3 to 10]

A pseudo liquid crystal panel was produced in the same manner as in example 3-7, except that the protective film a of the viewing-side polarizing plate 3-1 was changed to the protective film D.

[ examples 3 to 11]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 10, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 3 to 12]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 10, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 3 to 13]

(production of side polarizing plate for visual recognition 3-2)

The adhesive B was attached to the surface of the protective film C of the polarizing plate a. At this time, the surface of the protective film C and the surface of the adhesive B to be bonded are subjected to corona treatment. Next, the positive C plate 1 was bonded to the adhesive B surface of the produced polarizing plate a. At this time, the surface of the adhesive B bonded to the front C plate 1 was subjected to corona treatment. Further, an adhesive B was attached to the front C plate 1 side of the polarizing plate a. At this time, the surface of the polarizing plate a to which the front C plate 1 and the adhesive B are bonded is also subjected to corona treatment. Next, the λ/4 plate 1 was bonded to the adhesive B surface of the polarizing plate a. At this time, the surface of the adhesive B and the surface to be bonded of the λ/4 plate 1 were also subjected to corona treatment. The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/4 plate 1 was 45 ° (the λ/4 plate 1 was disposed so as to be rotated 45 ° counterclockwise with respect to the absorption axis of the polarizing plate when the protective film C was viewed from the protective film a). Finally, the adhesive a was attached to the λ/4 plate 1 side of the polarizing plate a. At this time, the surface of the λ/4 plate 1 to be bonded to the adhesive A was also subjected to corona treatment. This produces the viewing-side polarizing plate 2. The phase difference value in the thickness direction at a wavelength of 590nm was observed to be the same for the positive C-plate of the side polarizing plate 3-2 and the positive C-plate of the back side polarizing plate 3-1.

The thus-prepared polarizing plate 3-2 on the viewing side and the polarizing plate 3-1 on the back side were cut to a size of 155mm in the vertical direction by 96mm in the horizontal direction. At this time, the polarizing plates were cut so that the absorption axes thereof were 90 ° with respect to the longitudinal direction.

A viewing side polarizing plate 3-2 is bonded to the glass surface of the pseudo liquid crystal cell A on which a picture is drawn, and a back side polarizing plate 3-1 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 5 (b).

[ examples 3 to 14]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 13, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 3 to 15]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 13, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 3 to 16]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 13, except that the protective film a of the viewing side polarizing plate 3-2 was changed to the protective film D.

[ examples 3 to 17]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 16, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 3 to 18]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 16, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 3 to 19]

The thus prepared polarizing plate 3-2 for viewing side and the polarizing plate 3-2 for back side were cut to a size of 155mm in vertical direction by 96mm in horizontal direction. At this time, the polarizing plates were cut so that the absorption axes thereof were 90 ° with respect to the longitudinal direction.

A viewing side polarizing plate 3-2 is bonded to the glass surface of the pseudo liquid crystal cell A on which a picture is drawn, and a back side polarizing plate 3-2 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 5 (b).

[ examples 3 to 20]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 19, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 3 to 21]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 19, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 3 to 22]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 19, except that the protective film a of the viewing-side polarizing plate 2 was changed to the protective film D.

[ examples 3 to 23]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 22, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 3 to 24]

A pseudo liquid crystal panel was produced in the same manner as in examples 3 to 22, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 3-25 to 3-48]

A pseudo liquid crystal panel was produced in the same manner as in examples 3-1 to 3-24 except that the λ/4 plate 1 was changed to the λ/4 plate 2 and the λ/2 plate 1 was changed to the λ/2 plate 2. The correspondence between the numbers of the respective examples is shown in table 3 below.

[ Table 3]

[ example 4-1]

(production of side polarizing plate for visual recognition 4-1)

The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/4 plate 1 was-45 ° (when the protective film C was viewed from the protective film a, the λ/4 plate 1 was disposed so as to be rotated by 45 ° clockwise with respect to the absorption axis of the polarizing plate).

Finally, adhesive a was attached to the front C plate 1 side of polarizing plate a. At this time, the surface of the alignment C plate 1 and the bonding surface of the adhesive a are also subjected to corona treatment. This produces a viewing-side polarizing plate 4-1.

(production of Back-side polarizing plate 4-1)

The rear-side polarizing plate 4-1 was produced in the same manner as the viewing-side polarizing plate 4-1 except that the polarizing plate a was changed to the polarizing plate B and the λ/4 plate 1 was changed to the λ/2 plate 1. That is, the λ/2 plate 1 is bonded to the protective film C in the polarizing plate B via the adhesive B, the front C plate 1 is bonded via the adhesive B, and finally the adhesive a is laminated on the front C plate. The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/2 plate 1 was 45 ° (the λ/2 plate 1 was disposed so as to be rotated 45 ° counterclockwise with respect to the absorption axis of the polarizing plate when the protective film B was viewed from the protective film C). The phase difference value in the thickness direction at a wavelength of 590nm was visually recognized to be the same for the positive C-plate of the side polarizing plate and the positive C-plate of the back side polarizing plate.

The thus-prepared polarizing plate 4-1 on the viewing side and the polarizing plate 4-1 on the back side were cut to a size of 155mm in the vertical direction by 96mm in the horizontal direction. At this time, the polarizing plates were cut so that the absorption axes thereof were 90 ° with respect to the longitudinal direction.

A viewing side polarizing plate 4-1 is bonded to the glass surface of the pseudo liquid crystal cell B on which a picture is drawn, and a back side polarizing plate 4-1 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 6 (b).

[ example 4-2]

A pseudo liquid crystal panel was produced in the same manner as in example 4-1, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 4 to 3]

A pseudo liquid crystal panel was produced in the same manner as in example 4-1, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 4 to 4]

A pseudo liquid crystal panel was produced in the same manner as in example 4-1, except that the protective film a of the viewing-side polarizing plate 4-1 was changed to the protective film D.

[ examples 4 to 5]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 4, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 4 to 6]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 4, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 4 to 7]

(production of Back-side polarizing plate 4-2)

The adhesive B was attached to the surface of the protective film C of the polarizing plate B. At this time, the surface of the protective film C and the surface of the adhesive B to be bonded are subjected to corona treatment. Next, the front C plate 1 was laminated on the adhesive B surface of the produced polarizing plate B. At this time, the surface of the adhesive B bonded to the front C plate 1 was subjected to corona treatment. Further, an adhesive B was attached to the front C plate 1 side of the polarizing plate B. At this time, the surface of the polarizing plate B to be bonded to the front C plate 1 and the adhesive B were also subjected to corona treatment. Next, the λ/2 plate 1 was bonded to the adhesive B surface of the polarizing plate B. At this time, the surface of the adhesive B and the surface of the λ/2 plate 1 to be bonded were also subjected to corona treatment. The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/2 plate 1 was 45 ° (the λ/2 plate 1 was disposed so as to be rotated 45 ° counterclockwise with respect to the absorption axis of the polarizing plate when the protective film B was viewed from the protective film C). Finally, the adhesive a was attached to the λ/2 plate 1 side of the polarizing plate B. At this time, the surface of the λ/2 plate 1 to be bonded to the adhesive A was also subjected to corona treatment. The rear-side polarizing plate 4-2 was thus produced.

The thus-prepared polarizing plate 4-1 on the viewing side and the polarizing plate 4-2 on the back side were cut to a size of 155mm in the vertical direction by 96mm in the horizontal direction. At this time, the polarizing plates were cut so that the absorption axes thereof were 90 ° with respect to the longitudinal direction.

A viewing side polarizing plate 4-1 is bonded to the glass surface of the pseudo liquid crystal cell B on which a picture is drawn, and a back side polarizing plate 4-2 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 6 (b).

[ examples 4 to 8]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 7, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 4 to 9]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 7, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 4 to 10]

A pseudo liquid crystal panel was produced in the same manner as in example 4-7, except that the protective film a of the viewing-side polarizing plate 4-1 was changed to the protective film D.

[ examples 4 to 11]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 10, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 4 to 12]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 10, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 4 to 13]

(production of side polarizing plate for visual recognition 4-2)

The adhesive B was attached to the surface of the protective film C of the polarizing plate a. At this time, the surface of the protective film C and the surface of the adhesive B to be bonded are subjected to corona treatment. Next, the front C plate 1 was laminated on the adhesive B layer of the polarizing plate a thus produced. At this time, the surface of the adhesive B bonded to the front C plate 1 was subjected to corona treatment. Further, an adhesive B was attached to the front C plate 1 side of the polarizing plate a. At this time, the surface of the polarizing plate a to which the front C plate 1 and the adhesive B are bonded is also subjected to corona treatment. Next, the λ/4 plate 1 was bonded to the adhesive B surface of the polarizing plate a. At this time, the surface of the adhesive B and the surface to be bonded of the λ/4 plate 1 were also subjected to corona treatment. The bonding was performed such that the angle formed by the absorption axis of the polarizing plate and the λ/4 plate 1 was-45 ° (when the protective film C was viewed from the protective film a, the λ/4 plate 1 was disposed so as to be rotated by 45 ° clockwise with respect to the absorption axis of the polarizing plate). Finally, the adhesive a was attached to the λ/4 plate 1 side of the polarizing plate a. At this time, the surface of the λ/4 plate 1 to be bonded to the adhesive A was also subjected to corona treatment. Thereby, the viewing-side polarizing plate 4-2 was produced.

The thus-prepared polarizing plate 4-2 on the viewing side and the polarizing plate 4-1 on the back side were cut to a size of 155mm in the vertical direction by 96mm in the horizontal direction. At this time, the polarizing plates were cut so that the absorption axes thereof were 90 ° with respect to the longitudinal direction.

A viewing side polarizing plate 4-2 is bonded to the glass surface of the pseudo liquid crystal cell B on which a picture is drawn, and a back side polarizing plate 4-1 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 6 (b).

[ examples 4 to 14]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 13, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 4 to 15]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 13, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 4 to 16]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 13, except that the protective film a of the viewing side polarizing plate 4-2 was changed to the protective film D.

[ examples 4 to 17]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 16, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 4 to 18]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 16, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 4 to 19]

The thus-prepared polarizing plate 4-2 for viewing side and the polarizing plate 4-2 for back side were cut to a size of 155mm in the vertical direction by 96mm in the horizontal direction. At this time, the polarizing plates were cut so that the absorption axes thereof were 90 ° with respect to the longitudinal direction.

A viewing side polarizing plate 4-2 is bonded to the glass surface of the pseudo liquid crystal cell B on which a picture is drawn, and a back side polarizing plate 4-2 is bonded to the glass surface on the opposite side thereof, thereby producing a pseudo liquid crystal panel. The axis configuration is shown in fig. 6 (b).

[ examples 4 to 20]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 19, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 4 to 21]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 19, except that the positive C plate 1 was changed to the positive C plate 3.

[ examples 4 to 22]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 19, except that the protective film a of the viewing side polarizing plate 4-2 was changed to the protective film D.

[ examples 4 to 23]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 22, except that the positive C plate 1 was changed to the positive C plate 2.

[ examples 4 to 24]

A pseudo liquid crystal panel was produced in the same manner as in examples 4 to 22, except that the positive C plate 1 was changed to the positive C plate 3.

Examples 4-25 to 4-48

A pseudo liquid crystal panel was produced in the same manner as in examples 4-1 to 4-24 except that the λ/4 plate 1 was changed to the λ/4 plate 2 and the λ/2 plate 1 was changed to the λ/2 plate 2. The correspondence between the numbers of the respective examples is shown in table 4 below.

[ Table 4]

The pseudo liquid crystal panel thus produced was placed on the backlight thus produced, and it was confirmed whether or not a picture could be visually recognized. As a result of confirmation of visibility under external light, all of the pseudo liquid crystal panels exhibited good visibility even at 10000Lux

Industrial applicability

According to the polarizing plate group of the present invention, it is possible to provide a liquid crystal display device which can suppress reflection of external light and ensure good visibility even in an environment where external light is strong such as outdoors, and thus it is useful.

Description of the symbols

10 visual recognition side polarizing plate

20 rear surface side polarizing plate

30. 50 polarizing plate

31a, 31b, 51a, 51b protective film

36 surface treatment layer

32. 52 polarizing plate

32' first polarizer

52' second polarizer

34 lambda/4 board

54 lambda/2 plate

35. 55 positive C plate

61 Brightness enhancement film

60 liquid crystal cell

1 absorption axis of polarizing plate

Hysteresis axis of 2 lambda/4 plate

3 initial orientation direction of liquid crystal cell

Hysteresis axis of 4 lambda/2 plate

5 absorption axis of polarizing plate

Claims

1. A polarizing plate set comprising a viewing-side polarizing plate and a rear-side polarizing plate for bonding to both surfaces of an IPS mode liquid crystal cell having an in-plane retardation of 100nm to 200nm,

an absorption axis of the viewing-side polarizing plate is substantially orthogonal to an absorption axis of the rear-side polarizing plate,

the viewing side polarizing plate has a polarizing plate and a lambda/4 plate,

an angle formed by an absorption axis of the viewing-side polarizing plate and a slow axis of the lambda/4 plate is substantially 45 DEG,

2. The set of polarizer plates of claim 1,

the viewing-side polarizing plate includes a positive C plate disposed between the liquid crystal cell and the λ/4 plate.

3. The set of polarizer plates of claim 1,

the viewing-side polarizing plate includes a positive C plate disposed between the polarizing plate of the viewing-side polarizing plate and the λ/4 plate.

4. The polarizing plate set according to claim 2 or 3,

5. An IPS mode liquid crystal display device comprising an IPS mode liquid crystal cell having an in-plane retardation of 100nm to 200nm and the polarizing plate set defined in any one of claims 1 to 4 disposed thereon.

6. The IPS mode liquid crystal display device of claim 5, wherein,

the size of the IPS mode liquid crystal display device is 15 inches or less diagonally.

7. A polarizing plate set comprising a viewing-side polarizing plate and a rear-side polarizing plate for respectively bonding both surfaces of an IPS mode liquid crystal cell having an in-plane retardation of 400nm to 500nm,

the viewing side polarizing plate has a polarizing plate and a lambda/4 plate,

the retardation axis of the λ/4 plate is arranged in a substantially parallel relationship with respect to the initial alignment direction of the IPS mode liquid crystal cell.

8. The set of polarizing plates according to claim 7,

9. The set of polarizing plates according to claim 7,

the viewing-side polarizing plate includes a positive C plate disposed between the polarizing plate and the λ/4 plate.

10. The set of polarizing plates according to claim 8 or 9,

11. An IPS mode liquid crystal display device, which is obtained by arranging the polarizing plate set defined in any one of claims 7 to 10 in an IPS mode liquid crystal cell having an in-plane retardation value of 400nm to 500 nm.

12. The IPS mode liquid crystal display device of claim 11,

13. A polarizing plate set comprising a viewing-side polarizing plate and a rear-side polarizing plate for respectively bonding both surfaces of an IPS mode liquid crystal cell having an in-plane retardation of 100nm to 200nm,

an absorption axis of the viewing-side polarizing plate is substantially parallel to an absorption axis of the rear-side polarizing plate,

the viewing-side polarizing plate has a first polarizing plate and a lambda/4 plate,

the back-side polarizing plate has a second polarizer and a lambda/2 plate,

the slow axis of the lambda/4 plate is substantially orthogonal to the slow axis of the lambda/2 plate,

14. The set of polarizer plates of claim 13,

the viewing-side polarizing plate includes a positive C plate disposed between the liquid crystal cell and the λ/4 plate,

15. The set of polarizer plates of claim 13,

16. The set of polarizer plates of claim 13,

the viewing-side polarizing plate includes a positive C plate disposed between the first polarizing plate and the λ/4 plate,

17. The set of polarizer plates of claim 13,

18. The set of polarizing plates according to any one of claims 14 to 17,

the phase difference values in the thickness direction of the front C-plate included in the viewing-side polarizing plate and the front C-plate included in the rear-side polarizing plate are substantially equal to each other.

19. The set of polarizing plates according to any one of claims 14 to 17,

20. An IPS mode liquid crystal display device, which is obtained by arranging the polarizing plate set defined in any one of claims 13 to 19 in an IPS mode liquid crystal cell having an in-plane retardation value of 100nm to 200 nm.

21. The IPS mode liquid crystal display device of claim 20, wherein,

22. A polarizing plate set comprising a viewing-side polarizing plate and a rear-side polarizing plate for respectively bonding both surfaces of an IPS mode liquid crystal cell having an in-plane retardation of 400nm to 500nm,

the back-side polarizing plate has a second polarizer and a lambda/2 plate,

23. The set of polarizer plates of claim 22,

24. The set of polarizer plates of claim 22,

25. The set of polarizer plates of claim 22,

26. The set of polarizer plates of claim 22,

27. The set of polarizing plates according to any one of claims 23 to 26,

28. The set of polarizing plates according to any one of claims 23 to 26,

29. An IPS mode liquid crystal display device, which is obtained by arranging the polarizing plate set defined in any one of claims 22 to 28 in an IPS mode liquid crystal cell having an in-plane retardation value of 400nm to 500 nm.

30. The IPS mode liquid crystal display device of claim 29, wherein,