JP3517926B2 - Liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FTN type liquid crystal display device (hereinafter sometimes referred to as FTN type LCD).

[0002]

2. Description of the Related Art A liquid crystal display device is a large liquid crystal display device (STN type LCD) having a twisting angle of the major axis of liquid crystal molecules of 180 to 270 degrees, which is about 10 inches in size by a simple matrix drive system. It has become possible to use a display device, and it has come to be used in laptop type word processors, personal computers, etc., which require a large display capacity. But,
Since this STN LCD utilizes the birefringence of liquid crystal, it has drawbacks such as poor viewing angle characteristics, colored display, and low contrast. In order to solve these problems, an FTN LCD using a uniaxially oriented retardation film made of a thermoplastic resin was developed as a compensating retardation layer for compensating the birefringence of liquid crystal, and the display black and white and the contrast of It has become possible to improve.

[0003]

However, the viewing angle characteristics such as the decrease in contrast and the change in hue depending on the viewing angle have not yet been satisfied, and a liquid crystal display device excellent in viewing angle characteristics has been proposed. Development is desired. As a result of intensive studies to solve the above problems, the present inventors have found that such a problem can be solved by using a specific compensation retardation layer.

[0004]

That is, according to the present invention, a nematic liquid crystal molecule having a positive dielectric anisotropy is formed between a pair of transparent substrates having electrodes inside so that the long axis of the molecule does not exist in the state where no voltage is applied. A liquid crystal cell parallel to the substrate and having a molecular long axis twisted by 180 ° to 270 ° in the direction perpendicular to the transparent substrate; a pair of linearly polarizing films disposed outside the pair of transparent substrates; An FTN type liquid crystal display device comprising a compensating retardation layer disposed between a liquid crystal cell and a linearly polarizing film, wherein the compensating retardation layer comprises:
Vertical alignment film selected from the following: After forming a polymer liquid crystal exhibiting a nematic phase or a smectic phase, a crystalline phase (or glass phase) / liquid crystal phase transition temperature (Tg) or more,
Vertical alignment film obtained by vertical alignment by heat treatment at a temperature lower than liquid crystal phase / isotropic phase transition temperature (Ti), or after forming a polymerizable liquid crystal oligomer showing a nematic phase or a smectic phase, Tg or more Includes a uniaxially oriented retardation film made of a thermoplastic resin having a positive refractive index anisotropy, which is obtained by subjecting to a vertically oriented film by heat treatment at a temperature lower than Ti and polymerizing while maintaining the orientation. A uniaxially oriented retardation film made of a thermoplastic resin having a positive refractive index anisotropy, which is composed of a combination, and is arranged both on the liquid crystal cell side and between the liquid crystal cell and the pair of linearly polarizing films. The present invention relates to a liquid crystal display device.

The liquid crystal display device of the present invention is symmetrical and has an excellent viewing angle characteristic in an oblique direction. As shown in FIG. 10, the lower side of the FTN LCD is set at 0 ° and the counterclockwise direction is set. If you define an angle, it is 60 diagonally, especially in azimuth.
Excellent viewing angle characteristics in the directions of °, 120 °, 240 ° and 300 °.

As the polymer liquid crystal, either a main chain polymer liquid crystal or a side chain polymer liquid crystal can be used as long as it is a polymer liquid crystal having a nematic phase or a smectic phase in a liquid crystal state. Examples of the main chain type polymer liquid crystal include a wholly aromatic polyester polymer liquid crystal in which a group imparting liquid crystallinity (mesogen group) is linked by an ester bond, a mesogen group and a bent chain such as polymethylene, polyethylene oxide, and polysiloxane. A semi-rigid polyester-based polymer liquid crystal composed of a main chain to which flexibility is imparted is alternately bonded. Examples of the side chain type polymer liquid crystal include a linear or cyclic skeleton chain composed of methacrylic acid, acrylic acid, polymethylene, polyethylene oxide, polysiloxane and the like, and a mesogenic group via a spacer composed of a bent chain. Those with attached side chains are mentioned. A polysiloxane type is preferable, and a cyclic type is preferable.

The transition temperature of the liquid crystal phase / isotropic phase of the polymer liquid crystal is, for example, about 200 ° C. or lower, preferably 150.
It is below ℃.

Examples of the polysiloxane-based side chain type polymer liquid crystal include linear or cyclic polymer liquid crystal having a repeating unit shown below. N in the following formulas is an integer of 2-6.

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

The polymerizable liquid crystal oligomer exhibiting a nematic phase or a smectic phase is not particularly limited, but a polymerizable side chain type liquid crystal oligomer is preferable.

The polymerizable side chain type liquid crystal oligomer is, for example, a linear or cyclic oligomer composed of the following repeating units (I) and (II), and the repeating units (I) and (II And n ′ are respectively an integer of 1 to 20 and 4 ≦ n + n ′ ≦ 21. [In the formula, A is the following formula (III) or (IV) In the formula (III), —Si—O— is the main chain of the formula (I) or (II), and in the formula (IV), —C—CH ₂ — is the formula (I) or Is the backbone of (II),
R ₁ or R ₂ is located on the opposite side of the COO group; when A is of formula (III) in formula (I) and formula (II)
When A is the formula (III), R ₁ and R ₂ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms or a phenyl group; and when A is the formula (IV) in the formula (I), and Formula (II)
Wherein A is the formula (IV), R ₁ and R ₂ are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms; k and k ′ are each independently an integer of 2 to 10; and m 'are each independently 0 or _{1; Ar 1, Ar 2,} Ar 3 and Ar ₄ each independently represent a 1,4-phenylene group, 1,4-cyclohexadiene down group, pyridine-2,5 Diyl group or pyrimidine-2,5-
Be diyl; L and L 'is -CH ₂ -O independently _{-, - O-CH 2 -} , -COO
-, -OCO-, -CH ₂ -CH _2- , -CH = N-, -N = CH- or Is a divalent group represented by: p and p ′ are each independently 0 or 1, and R is a halogen, a cyano group, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. R'is hydrogen or an alkyl group having 1 to 5 carbon atoms. ]

The skeleton chain is preferably a cyclic structure, and A is preferably -Si-O-. The ratio of n and n'is 1:
A range of 3 to 3: 1 is preferred.

Each of k and k'is preferably an integer of 2 to 6, and each of m and m'is preferably 1.

Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ are each preferably a 1,4-phenylene group, and L and L ′ are —CH ₂ —CH ₂ —, —COO— or —OCO. -Group is preferable, and -COO- group is particularly preferable.

As R, a cyano group is preferable.

Examples of the non-polymerizable mesogenic group in the repeating unit (I) are shown below.

[0030]

[0031]

[0032]

[0033]

Among these, the numbers 31 to 36 are preferable.

Examples of the polymerizable mesogenic group in the repeating unit (II) are shown below.

[0036]

[0037]

[0038]

Of these, numbers 253 to 258 are preferred.

In the case of the polymerizable side chain type liquid crystal oligomer, the liquid crystal phase / isotropic phase transition temperature is, for example, 200 ° C. or lower,
The temperature is preferably 170 ° C. or lower, more preferably 150 ° C. or lower. The crystal phase (or glass phase) / liquid crystal phase transition temperature is, for example, room temperature or lower, preferably 0 ° C. or lower.

As a substrate for forming a polymer liquid crystal or a polymerizable liquid crystal oligomer, an optically transparent and isotropic resin substrate, a linearly polarizing film, a thermoplastic resin having a positive refractive index anisotropy And a uniaxially oriented retardation film made of When a high molecular liquid crystal or a polymerizable liquid crystal oligomer is formed on the surface of a uniaxially oriented retardation film made of a linearly polarized film or a thermoplastic resin having a positive refractive index anisotropy, it is subjected to heat treatment or the like for vertical alignment. After being formed into a film, it can be directly incorporated into a liquid crystal display device. When the vertical alignment film is formed by performing heat treatment or the like on the polarizing film, for example, a uniaxially oriented retardation film made of a thermoplastic resin having positive refractive index anisotropy is attached to the surface of the vertical alignment film. Then, by laminating this with a liquid crystal cell so that the uniaxially oriented retardation film made of a thermoplastic resin having a positive refractive index anisotropy is on the liquid crystal cell side, the positive refractive index anisotropy is also increased. When a vertical alignment film is formed on a uniaxially oriented retardation film made of a thermoplastic resin having, for example, a linear polarizing film is attached to the surface of the vertical alignment film, which is a uniaxially oriented retardation film. By laminating the liquid crystal cell on the liquid crystal cell side, a linear polarization film / vertical alignment film / retardation film / liquid crystal cell can be formed.

When the vertical alignment film is formed on an optically transparent and isotropic resin substrate, for example, a heat having a positive refractive index anisotropy is formed on the surface of the resin substrate or the surface of the vertical alignment film. Laminate a uniaxially oriented retardation film made of a plastic resin and attach it to a liquid crystal cell so that the uniaxially oriented retardation film made of a thermoplastic resin having a positive refractive index anisotropy is on the liquid crystal cell side. , By sticking a linear polarizing film on the opposite side, a linear polarizing film / vertical alignment film / resin substrate / retardation film / liquid crystal cell, or a linear polarization film / resin substrate / vertical alignment film / retardation film / liquid crystal cell Can be configured. An adhesive or the like can be used for the bonding.

Optically isotropic means that when nX is the maximum in-plane refractive index, nY is the minimum in-plane refractive index, nZ is the refractive index in the film thickness direction, and d is the film thickness. And (nX-nY) × d is 20 nm or less, and ((nX +
nY) / 2-nZ) xd is 200 nm or less. Preferably, (nX-nY) * d is 10 nm or less, and ((nX + nY) / 2-nZ) * d is 100 nm or less. The optically transparent and isotropic resin substrate is not particularly limited, but preferably has a glass transition temperature of 100 ° C or higher, more preferably 110 ° C or higher. Examples of resins include polycarbonate, polysulfone, polyarylate, polyether sulfone, cellulose diacetate, cellulose triacetate, polyethylene terephthalate, polyethylene naphthalate, polyvinyl alcohol, polystyrene, and polymethylmethacrylate. Among them, polycarbonate, polysulfone, Polyarylate, cellulose triacetate and polyethylene terephthalate are preferred. An example of the FTN type LCD of the present invention is shown in FIGS.

A method of forming a vertical alignment film of polymer liquid crystal or the like will be described below in the case of using an optically transparent and isotropic resin substrate. A linear polarization film or a uniaxial alignment retardation film will be described below. When the vertical alignment film is formed on the surface of, the same process can be performed. The surface of the transparent resin substrate is preferably hydrophilic or hydrophobic. The hydrophilicity means, for example, that the contact angle with water is 60 ° or less, preferably 50 ° or less. Hydrophobic means, for example, that the contact angle with water is 85 ° or more, preferably 90 ° or more.

As the hydrophilic resin substrate, a hydrophilic polymer film such as polyvinyl alcohol, a surface of a cellulose triacetate or cellulose diacetate film is saponified, a surface of a polymer film is hydrophilic, and the like. Can be mentioned. The hydrophilization treatment is not particularly limited, but treatment with oxygen plasma, a method of applying a hydrophilic polymer on the surface, a method of applying a surfactant, and the like can be used.

As the hydrophilic resin substrate, a film obtained by forming a film of a cellulose resin such as cellulose triacetate or cellulose diacetate by a solvent casting method and saponifying the surface is preferable.

As the hydrophobic treatment, a method of applying a fluoropolymer, a method of applying a surfactant such as lecithin,
A method of reacting a silane coupling agent, a titanium coupling agent or the like can be used.

In the FTN LCD of the present invention, when the vertical alignment film is formed on an optically transparent and isotropic resin substrate, the resin substrate is arranged on either the uniaxially oriented film side or the polarizing film side. Good.

The method for forming the polymer liquid crystal or the polymerizable liquid crystal oligomer is not particularly limited. For example, a liquid in which a high molecular liquid crystal or a polymerizable liquid crystal oligomer is dissolved in a solvent capable of dissolving a high molecular liquid crystal or a polymerizable liquid crystal oligomer and having little dissolution or swelling of a substrate material is subjected to a roll coating method, a gravure coating method or a bar coating method. A coating method such as a coating method, a spin coating method, a spray coating method, a printing method, or a dipping method, or a polymer liquid crystal or a polymerizable liquid crystal oligomer is heated to a crystal phase (or glass phase) / liquid crystal phase transition temperature or higher. A method of applying the same by a method similar to the above-mentioned method can be mentioned.

Among these, the roll coating method, gravure coating method, bar coating method, spin coating method and dipping method using a polymer liquid crystal solution or a polymerizable liquid crystal oligomer solution are preferred, and optical such as R40 / R0 depending on the film thickness. The characteristics can be adjusted.

The heat treatment temperature (Tt) for orienting the polymer liquid crystal or the polymerizable liquid crystal oligomer after film formation in the direction perpendicular to the film surface is set to the crystal phase (or glass phase) of the polymer liquid crystal or the polymerizable liquid crystal oligomer / It is preferably equal to or higher than the liquid crystal phase transition temperature (referred to as Tg) and lower than the liquid crystal phase / isotropic phase transition temperature (referred to as Ti). Further, it is preferably not higher than the glass transition temperature of the substrate. Tg + 30 for polymerizable liquid crystal oligomers
℃ ≦ Tt <Ti is preferable, Tg + 40 ° C. ≦ Tt <Ti
Is more preferable.

The heat treatment time is not particularly limited, but is, for example, 1 minute or longer, preferably 2 minutes or longer.

In the case of the polymerizable liquid crystal oligomer, after the heat treatment, the liquid crystal oligomer is polymerized while maintaining the vertical alignment. The polymerization method is not particularly limited, and photopolymerization, radiation polymerization of γ rays or the like, thermal polymerization and the like can be used, but photopolymerization is preferable. In the case of photopolymerization or thermal polymerization, a known polymerization initiator can be used.

The uniaxially oriented retardation film is not limited to a perfect uniaxially oriented film, but even if biaxially oriented film is provided, it has a refractive index anisotropy in the film plane, Any film can be used as long as it shows a retardation similar to that of the uniaxially oriented film when seen.

The thermoplastic resin used for the uniaxially oriented retardation film made of a thermoplastic resin having a positive refractive index anisotropy includes polycarbonate, polysulfone, polyarylate, polyether sulfone, polyethylene terephthalate, polyvinyl alcohol, and acetic acid. Examples thereof include cellulose, and polycarbonate and polysulfone are preferable. As a method for producing the raw film, a solvent casting method, an extrusion molding method, a molding method such as a pressing method can be used, and as a method for stretching the raw film, a lateral stretching method using a tenter, a roll-rolling method, A method such as a compression stretching method between rolls can be used. Preferred is a method of transversely stretching a raw film formed by a solvent casting method with a tenter.

The retardation measured by injecting the measuring light in the direction perpendicular to the plane was R0, and the retardation measured by injecting the measuring light at an inclination of 40 ° with the direction of the maximum in-plane refractive index being the inclination axis was R40. Then, the compensation retardation layer is 1.
It is preferable that 10 ≧ R40 / R0 ≧ 0.90.
06 ≧ R40 / R0 ≧ 0.94 is more preferable.

[0057]

The FTN LCD of the present invention is excellent in the left-right symmetry of the isocontrast curve and in the viewing angle characteristics in the oblique direction.

[0058]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. The measurement of the isocontrast curve is LCD-700 manufactured by Otsuka Electronics Co., Ltd.
It was carried out by the transmission method using 0. The voltage applied to the liquid crystal display device was set to a state where the contrast was the best when the liquid crystal display device in the actual driving state was visually observed from the front. The retardation value of the uniaxially oriented retardation film is measured by a spectroscope (Otsuka Electronics Co., Ltd.) in which two polarizing prisms are arranged in parallel in the optical system.
MCPD-1000) manufactured by Mitsui Chemicals, Inc. was used to determine the maximum wavelength of the interference spectrum.

Example 1 As a polymerizable liquid crystal oligomer, 4- (allyloxy)-
Benzoic acid-4'-cyanophenyl ester and 4- (allyloxy) -benzoic acid-4'-methacryloyloxyphenyl ester at a mixing ratio of 1: 1 are described in Japanese Patent Publication No. 63-41400 and pentamethylcyclopentasiloxane. A cyclic pentasiloxane liquid crystal oligomer having a non-polymerizable mesogen group and a polymerizable mesogen group in a side chain at a ratio of about 1: 1 (Tg = 18.7 ° C., Ti =
117.5 ° C.) was used. With a thickness of 80 μm (nX-nY
) × d is 6 nm, and ((nX + nY) / 2-nZ) × d is 50 nm. A cellulose acetate film (trade name “Fujitac SH-80” manufactured by Fuji Photo Film Co., Ltd.) is surface-saponified. A 30% toluene solution of the above-mentioned polymerizable liquid crystal oligomer was formed on the film by a gravure coating method so that the film thickness after drying would be 2.8 μm, and heat-treated at 80 ° C. for 2 minutes for vertical alignment. Then, while maintaining the alignment, the film was irradiated with ultraviolet rays (integrated light amount: 500 mJ / cm ² ) to obtain a continuous film (hereinafter referred to as a film) on which a vertical alignment film was formed. Also, as the uniaxially oriented retardation film, a uniaxially oriented retardation film obtained by uniaxially stretching a solvent cast film of polycarbonate (trade name "Sumikalite SEF-360428", manufactured by Sumitomo Chemical Co., Ltd., in-plane Retardation of 428 nm; hereinafter referred to as a film) was used. With film and film,
Two compensatory retardation layers (R40 / R0 = 0.9850) were obtained by laminating the cellulose acetate film / vertical alignment film / adhesive / uniaxially oriented retardation film in this order. These are word processors (brand name “OASYS 30LX-401”,
A uniaxially oriented retardation film was laminated between the upper and lower polarizing films and the liquid crystal cell of the FTN type LCD mounted in Fujitsu Ltd. so that the retardation film was on the liquid crystal cell side (FIG. 1). reference). This FTN LCD has a small change in contrast depending on the viewing angle, and is particularly symmetrical and has excellent viewing angle characteristics in the azimuth angles of 60 °, 120 °, 240 ° and 300 °. The isocontrast curve is shown in FIG.

Example 2 A film on which a vertical alignment film was formed (hereinafter referred to as a film) was obtained in the same manner as the film in Example 1 except that the film thickness after drying was 3.3 μm. Compensation retardation layer (R40 / R0 = 0.9552) laminated in the order of vertical alignment film / 3 cellulose acetate film / adhesive / uniaxially oriented retardation film using film and film.
I got two. This is performed in the same manner as in Example 1, and the FTN type L
It was mounted on a CD (see Figure 2). This FTN LCD is
The change in contrast depending on the viewing angle was small, and in particular, it was symmetrical and was excellent in viewing angle characteristics in the azimuth angles of 60 °, 120 °, 240 ° and 300 °. The isocontrast curve is shown in FIG.

COMPARATIVE EXAMPLE 1 Two FTN-type L films, which were the same as those in Example 1, were used.
It was laminated between the polarizing film above and below the CD and the liquid crystal cell (see FIG. 5). This FTN type LCD is an FTN according to the present invention.
Compared with the TN LCD, the viewing angle characteristics, particularly the viewing angle characteristics in the oblique direction were inferior. The isocontrast curve is shown in FIG.

Comparative Example 2 A solvent cast film of polystyrene was uniaxially stretched to obtain a uniaxially oriented retardation film (referred to as a film) having an in-plane retardation of 428 nm. Using the same FTN LCD as in Example 1, a film was mounted between the upper polarizing film and the liquid crystal cell, and a film was mounted between the lower polarizing film and the liquid crystal cell. This FTN LCD is
Compared with the FTN LCD according to the present invention, the viewing angle characteristics are widened, but the left-right symmetry is inferior. The isocontrast curve is shown in FIG.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a first example of the configuration of an FTN type LCD according to the present invention.

FIG. 2 is a schematic sectional view showing a second example of the configuration of the FTN LCD according to the present invention.

FIG. 3 is a schematic sectional view showing a third example of the configuration of the FTN type LCD according to the present invention.

FIG. 4 is a schematic sectional view showing a fourth example of the configuration of the FTN LCD according to the present invention.

FIG. 5 is a schematic cross-sectional view showing the configuration of a conventional FTN LCD.

FIG. 6 is a diagram showing isocontrast curves in Example 1.

FIG. 7 is a diagram showing isocontrast curves in Example 2.

FIG. 8 is a diagram showing isocontrast curves in Comparative Example 1.

9 is a diagram showing isocontrast curves in Comparative Example 2. FIG.

FIG. 10 is a perspective view illustrating an azimuth angle of an FTN LCD.

[Explanation of symbols]

1, 11: Polarizing film. 2, 12: optically transparent and isotropic resin substrate. 3, 13: Vertical alignment film. 4, 14: Uniaxially oriented retardation film made of a thermoplastic resin having positive refractive index anisotropy. 5, 15: Adhesive. 6: STN type liquid crystal cell. 30: LCD screen. 31: Downward of the LCD screen. 32: Vertical direction of LCD screen. 33: LCD viewing direction. 34: Azimuth angle of LCD viewing direction. 35: Inclination angle of LCD viewing direction.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akiko Shimizu 2-10-1, Tsukahara, Takatsuki-shi, Osaka Sumitomo Chemical Co., Ltd. (72) Inventor Koji Higashi 2-10-1, Tsukahara, Takatsuki-shi, Osaka Sumitomo Chemical Industry Co., Ltd. (56) Reference JP-A-3-85519 (JP, A) JP-A-2-256021 (JP, A) JP-A-4-412 (JP, A) JP-A-5-241019 ( JP, A) JP-A-5-142531 (JP, A) JP-A-4-16916 (JP, A) JP-A-1-282519 (JP, A) Actually open 2-102501 (JP, U) (58) ) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/1335 510 G02F 1/133 500 G02F 1/1337

Claims (3)

(57) [Claims] 1. A pair of transparent substrates having electrodes inside,
The nematic liquid crystal molecules having positive dielectric anisotropy have a structure in which the long axis of the molecule is parallel to the substrate and the long axis of the molecule is twisted by 180 to 270 degrees in the direction perpendicular to the transparent substrate when no voltage is applied. a pair of linear polarizing film, and FTN liquid crystal display device comprising a compensating retardation layer disposed between the liquid crystal cell and the linear polarizing film disposed configured liquid crystal cell Le, outside of the pair of transparent substrates there are, the compensating retardation layer, vertical alignment films selected from the following: - after film formation the polymer liquid crystal exhibiting a nematic phase or a smectic phase, a crystal phase (or glass phase) / liquid crystal phase transition temperature ( Tg) or above ,
Vertical alignment film obtained by heat treatment at a temperature lower than the liquid crystal phase / isotropic phase transition temperature (Ti) for vertical alignment , or after forming a polymerizable liquid crystal oligomer showing a nematic phase or a smectic phase , Tg or more Includes a uniaxially oriented retardation film made of a thermoplastic resin having a positive refractive index anisotropy , which is obtained by subjecting to a vertically oriented film by heat treatment at a temperature lower than Ti and polymerizing while maintaining the orientation. combinations Ri Do from, as uniaxially oriented retardation film made of a thermoplastic resin having a positive refractive index anisotropy is a liquid crystal cell side, and disposed both between the liquid crystal cell and a pair of linear polarizing film
Liquid crystal display device characterized by being 2. A compensating retardation layer After forming a side chain type polymer liquid crystal having a polysiloxane skeleton chain exhibiting a nematic phase or a smectic phase is subjected to a heat treatment at a temperature of less than Tg Ti claim is a combination comprising a uniaxially oriented retardation film made of a thermoplastic resin having a vertical alignment film obtained by vertically aligned, and positive refractive index anisotropy 1
The described liquid crystal display device. 3. A compensating retardation layer After forming a heavy polymerizable side chain type liquid crystal oligomer shows the nematic phase or smectic phase, vertically aligned by heat treatment at a temperature of less than Tg Ti, orientation a combination comprising a uniaxially oriented retardation film made of a thermoplastic resin having vertically aligned film obtained by polymerizing while, and positive refractive index anisotropy hold is claim 1
The described liquid crystal display device.