JPH08297210A - Optical film and liquid crystal display device - Google Patents

Abstract

PURPOSE: To provide an optical film which is effective to improve visual angle characteristics and to provide a liquid crystal display device using this film. CONSTITUTION: This optical film is produced by laminating (a) at least one light-controlling plate, (b) at least one phase difference film comprising a thermoplastic resin and (c) a polarizing film. The light-controlling plate (a) is obtd. by preparing a compsn. containing two or more kinds of photopolymerizable monomers and/or oligomers having different refractive indices from each other, forming the compsn. into a film, and then irradiating the film with UV rays. The liquid crystal display device is equipped with such a liquid crystal cell that consists of two glass substrates having electrodes at least one of which is transparent and that a nematic liquid crystal layer having positive dielectric anisotropy and 60 to 120 deg. or 180 to 270 deg. twisted angle is held between the two glass substrates. The optical film above described is disposed on the upper and/or lower side of the liquid crystal cell.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel optical film used in a liquid crystal display device and the like and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art Liquid crystal display devices have been increasingly used in portable televisions, notebook personal computers and the like because of their features such as light weight, thin shape and low power consumption. Currently, the mainly used TN type liquid crystal display device of the active matrix drive (hereinafter,
AM-TN-LCD) and a simple matrix-driven FTN type liquid crystal display device (hereinafter referred to as SM-FTN-LCD). AM-TN-LCD and SM-FTN-L
A liquid crystal display device such as a CD has a problem that viewing angle characteristics such as a decrease in contrast and a change in hue when viewed from an oblique direction are not sufficient. This viewing angle characteristic is
This is mainly due to the angle dependence of the retardation of the liquid crystal cell and the angle dependence of the retardation of the retardation film when a retardation film is used.

In order to improve this viewing angle characteristic, studies have been made to improve the angle dependence of the retardation of the retardation film, but it has not been sufficiently improved, and therefore, JP-A-H07-76107.
Improvement of viewing angle characteristics using a light control plate as disclosed in JP-A-64069 has also been studied. Also, SM-
The FTN-LCD has a problem that the contrast and the response speed are low as compared with the AM-TN-LCD, but as a method for improving this, a liquid crystal having a large birefringence is used to reduce the cell gap of the liquid crystal cell. The method is known.
However, a liquid crystal having a large birefringence generally has a large wavelength dependence of the birefringence, and if the wavelength dependence of the birefringence of the retardation film used together with this liquid crystal is not compatible with the liquid crystal, the contrast is lowered. It causes problems such as To solve this problem, it is effective to use a retardation film having a wavelength dependency of birefringence larger than that of a conventional one. It is exemplified in Japanese Patent Application No. 6-282041. However, these films do not necessarily have sufficient improvement in viewing angle characteristics.

[0004]

As a result of intensive studies to solve the above problems, as a result of laminating at least one light control plate, at least one retardation film made of a thermoplastic resin and a polarizing film. It was found that a liquid crystal display device having excellent viewing angle characteristics can be obtained by using such a film, and completed the present invention.

That is, the present invention is as follows. [1] (a) at least one light control plate obtained by irradiating with ultraviolet rays after forming a composition containing two or more kinds of photopolymerizable monomers and / or oligomers having different refractive indexes into a film shape 1. An optical film, comprising: one sheet, (b) at least one retardation film made of a thermoplastic resin, and (c) a polarizing film. [2] The optical film as described in the item [1], wherein the composition contains a compound having a refractive index different from that of the photopolymerizable monomer or oligomer and having no photopolymerizability. [3] The optical film as described in the item [1] or [2], wherein the difference in the refractive index of at least two kinds of the photopolymerizable monomer and / or oligomer is 0.01 or more. [4] The light control plate has a domain interval of 1 μm to 20 μm
The optical film as described in the item [1], which is a refractive index modulation type light control plate. [5] The light control plate is a light control plate having a light ray incident angle region having a light ray scattering ability of 30% or more and a light ray incident angle region having less than 30% of the haze value. ]
Item or the optical film according to item [4]. [6] The optical film as described in the above item [5], which has a maximum haze value of 30% to 85% in a light incident angle range showing a light scattering ability. [7] The optical film as described in the item [1], wherein the retardation film is a thermoplastic resin having positive refractive index anisotropy. [8] The retardation film has a ratio α [α = R (486) of the retardation value R (486) at the wavelength of 486 nm to the retardation value R (589) at the wavelength of 589 nm.
/ R (589)] is 1.07 or more, which is a thermoplastic resin having a positive anisotropy of refractive index.

[0006]

[9] At least one of the two glass substrates having an electrode is transparent, has a positive dielectric anisotropy between the two glass substrates, and has a twist angle of 60 ° to 1
A liquid crystal display device in which at least one optical film described in the item [1] is arranged above and / or below the liquid crystal cell in a liquid crystal cell in which a nematic liquid crystal layer of 20 degrees is arranged. [10] A nematic in which at least one of two glass substrates having an electrode is transparent, has a positive dielectric anisotropy between the two glass substrates, and has a twist angle of 180 to 270 degrees. A liquid crystal display device comprising a liquid crystal cell in which a liquid crystal layer is arranged, and at least one optical film described in the above item [1] is arranged above and / or below the liquid crystal cell.

The light control plate used in the present invention is formed by using at least two kinds of photopolymerizable monomers and / or oligomers having mutually different refractive indexes.

Examples of these photopolymerizable monomers and oligomers include 2,4,6-tribromophenyl acrylate, tribromophenoxyethyl acrylate, and 2-, 6-tribromophenyl acrylate as exemplified in JP-A-7-64069.
Hydroxy-3-phenoxypropyl acrylate, tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, pentenyl oxyethyl acrylate, phenyl carbitol acrylate and polyol polyacrylate, isocyanuric acid skeleton polyacrylate, melamine acrylate, hydantoin skeleton polyacrylate, urethane acrylate And so on.

As the photopolymerizable monomer and oligomer, two or more kinds having different refractive indexes are used. Examples of the combination include two kinds selected from monomers, one kind of monomer and one kind of oligomer, two kinds selected from oligomer, or a combination of one or more kinds of monomers or oligomers added to these combinations. In these combinations, at least two of them are preferable in that the difference in refractive index is 0.01 or more in order to obtain the required light scattering ability.

Further, in order to improve the curability of the above composition for a light control plate, it is preferable to use a photopolymerization initiator. As a photopolymerization initiator, JP-A-7-64069 can be used.
Examples thereof include benzophenone, 2-hydroxy-2-methylpropiophenone, benzyl, Michler's ketone, 2-chlorothioisanthone and the like.

Compounds having a refractive index different from that of the above-mentioned photopolymerizable monomers and oligomers and having no photopolymerizability include styrene resins such as polystyrene, acrylic resins such as polymethylmethacrylate, polyethylene oxide, polyvinylpyrrolidone, Examples thereof include resins such as polyvinyl alcohol, organic halogen compounds, organic silicon compounds, plasticizers, plastic additives such as stabilizers, and the like. These can also be blended in the above resin composition for a light control plate as a high refractive index component or a low refractive index component. The difference in refractive index between at least one photopolymerizable monomer or oligomer and the compound not photopolymerizable is preferably 0.01 or more.

Further, the average particle size is 0.05 μm to 20 μm.
It is also possible to add 0.01 to 5 parts by weight of the above-mentioned filler and to add an ultraviolet absorber.

The above composition is exemplified by Japanese Patent Application Laid-Open No. 7-64069, which is used in the embodiment of the present invention and is cured by a photo-curing device as shown in FIGS. A light control plate that selectively scatters light can be obtained. Further, a thermosetting mechanism may be used together within a range that does not hinder performance expression. At the time of curing, it is preferable to apply these compositions onto, for example, a substrate, or to enclose the composition in a cell to form a film, and then irradiate the composition with ultraviolet rays from a specific direction to cure the composition. By this method, a light control plate that selectively scatters incident light having a desired angle can be obtained.

The light source used in photopolymerization is not particularly limited as long as it emits ultraviolet rays that contribute to photopolymerization.
The shape of the light source is appropriately selected depending on the light control function required for the optical film of the present invention. As shown in Japanese Patent Application No. 6-3236, when it is desired to make the light scattering power of the light control plate equal in all directions, it is most preferable to use parallel rays such as sunlight, but spherical or box. In the case of a rod-shaped light source in which the ratio of the length in the major axis direction to the length in the minor axis direction of the lamp is 2: 1 or less, the same performance can be exhibited. A linear or rod-shaped light source is preferably used as the irradiation light source when the scattering characteristic is provided only in one direction such as the vertical direction or the horizontal direction.

The selective scattering power with respect to the light incident angle of the light control plate is defined by the haze value with respect to the light incident angle of the light control plate. The light control plate used in the present invention has a characteristic that the haze value changes depending on the light ray incident angle, and has a light ray incident angle region (scattering angle region) having a haze value of 30% or more and a light scattering ability other than that. Those having a light ray incident angle range having a valence of less than 30% and exhibiting no light scattering ability are preferable. The maximum haze value in the scattering angle region is preferably 30% to 85% from the viewpoint of display clarity.

The thickness of the light control plate of the present invention is required to be 10 μm or more for exhibiting the light scattering ability, and it is appropriately determined so that the required light scattering ability can be obtained with a thickness of 10 μm or more, but it is 50 μm to 300 μm. Is preferably used.

The light control plate used in the present invention is Japanese Patent Application No.
No. 3236, it is produced by utilizing the property of photopolymerization and curing while phase separation occurs when a composition containing a specific photopolymerizable monomer and / or oligomer is irradiated with ultraviolet rays. Therefore, according to this method, the domain spacing is 1 even when a mask is not used during ultraviolet irradiation.
A smooth refractive index modulation type light control plate having a thickness of μm to 20 μm can be produced. Since this phase separation has a continuous interface, when light is transmitted through the obtained light control plate, reflection does not occur at the interface and the light transmittance does not drop. Further, since this light control plate does not have a regular structure unlike the phase grating, moire fringes do not occur. Furthermore, since this light control plate can be manufactured only by the step of irradiating the film composition with ultraviolet rays without using a mask, the manufacturing method is simple and the mass productivity is excellent.

A polycarbonate resin film, a methacrylic resin sheet, a polyethylene terephthalate film, or the like can be used as a substrate to which the above composition is applied.

The retardation film made of a thermoplastic resin used in the present invention is not particularly limited, but it is disclosed in JP-A 2-4240.
A retardation film as described in Japanese Patent No. 6 can be used.

As the retardation film made of a thermoplastic resin, a retardation film made of a thermoplastic resin having positive refractive index anisotropy in terms of transparency and mechanical strength is preferably used. As the thermoplastic resin having a positive refractive index anisotropy, a polycarbonate resin, a polysulfone resin,
Polyarylate resin, polyether sulfone resin,
Polyester resins, polyvinyl alcohol resins, cellulose resins and the like are preferably used. In addition, as shown in Japanese Patent Application No. 6-282041, SM-FT
When a liquid crystal having a large birefringence is used for improving the response speed in the N-LCD, the wavelength dependence of the birefringence of the liquid crystal becomes large. In order to obtain high contrast, it is necessary to increase the wavelength dependence of the birefringence of the retardation film, that is, the wavelength dependence of the retardation. The wavelength dependence of the retardation is the ratio α [α = R (486) / of the retardation value R (486) at the wavelength 486 nm to the retardation value R (589) at the wavelength 589 nm.
R (589)] and improved response speed SM-
A retardation film having α of 1.07 or more is more suitable for FTN-LCD, etc.
Compared with the polycarbonate resin (α = 1.06) used for M-FTN-LCD, polysulfone resin (α = 1.09) and polyether sulfone resin (α =
1.11) and the like are preferably used.

Further, polysulfone resin is the upper limit as a resin having a large α that can be produced by a mass production apparatus, but as shown in Japanese Patent Application No. 6-282041, α is 0.
It is also possible to produce a retardation film having α of 1.10 or more by using a method of laminating two orienting films having a difference of 03 or more so that their slow axes are orthogonal to each other.

The method for producing the retardation film made of the above-mentioned thermoplastic resin is not particularly limited, and a raw film formed by a solvent casting method or the like is stretched between rolls,
A uniaxial stretching method such as a tenter stretching method is used. Further, when two oriented films having different α of 0.03 or more are laminated so that the slow axes are orthogonal to each other, as shown in Japanese Patent Application No. 6-282041, the angle dependence of retardation is In order to reduce the amount, it is also possible to use a method in which a vertical alignment film of polymer liquid crystal is further laminated on the laminated film, or the orientation film is thermally relaxed to reduce the angle dependence of the retardation.

The polarizing film used in the present invention is not particularly limited. A stretched polyvinyl alcohol film is dyed with iodine or a dichroic dye, and transparent films are attached to both surfaces as protective films. Iodine-based polarizing film dyed with iodine, which has high polarization performance, when durability is not demanding, and dichroic dye, which has slightly lower polarization performance but superior durability, when durability is demanding. The dye-based polarizing film described above is used.

The optical film of the present invention can be obtained by laminating the above-mentioned light control plate, retardation film and polarizing film. The order of lamination is appropriately determined according to the required optical characteristics, but the polarizing film / light control plate / retardation film, light control plate / polarizing film / retardation film, polarizing film / retardation film / light control plate, etc. The structure of can be illustrated. Further, when a plurality of light control plates having a scattering property in one direction are used to provide the scattering properties in a plurality of specific directions, a polarizing film / light control plate / light control plate / retardation film, a light control plate It is also possible to adopt a structure such as / polarizing film / light control plate / retardation film. Further, when two retardation films are used, a structure such as a light control plate / polarizing film / retardation film / retardation film can be adopted.

The laminating method is not particularly limited, but
For example, a method of producing each of a light control plate, a retardation film, and a polarizing film individually and laminating them with an adhesive or an adhesive, and directly using a polarizing film as a substrate when manufacturing the light control plate A method of laminating a plate / polarizing film laminated structure with a retardation film using an adhesive or an adhesive can be used.

When the optical film of the present invention is arranged on the surface of a liquid crystal display device and used, an additional function can be imparted to the surface of the optical film. For example, a transparent protective film for preventing scratches may be attached to the surface of the outermost film, or a hard coat layer for preventing scratches may be provided. Further, in order to prevent reflection of external light, it is also possible to form an anti-glare layer that forms fine irregularities on the surface and diffusely reflects external light, or an antireflection layer composed of a multilayer film of dielectric thin films. Further, a transparent protective film having an antireflection layer formed thereon may be attached, or the antireflection layer may be formed on the hard coat layer.

The method for laminating the optical film of the present invention on a liquid crystal cell is not particularly limited, and a laminated film having a constitution that can obtain required display characteristics is provided on the upper side and / or the lower side of a liquid crystal panel with an adhesive. It may be pasted by using such as.

Regarding the lamination angle of the light control plate, the retardation film and the polarizing film used in the present invention to the liquid crystal panel, for example, the polarizing film and the retardation film have the optimum contrast and hue when viewed from the front of the liquid crystal panel. The angle between the absorption axis of the polarizing film and the slow axis of the retardation film seen from the direction perpendicular to the film surface is set on the panel so that the scattering direction of the light control plate is the viewing angle characteristic of the liquid crystal display device. It is set so that it can be improved. Then, by laminating the light control plate, the retardation film and the polarizing film according to these set angles, the optical film of the present invention can be obtained.

[0029]

The optical film of the present invention has the functions of a light control plate, a retardation film and a polarizing film. By applying this optical film to a liquid crystal panel, a liquid crystal display device having excellent viewing angle characteristics can be obtained. You can

[0030]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. The retardation value R (486) at the wavelength of 486 nm and the wavelength of 5
Ratio of retardation value R (589) at 89 nm α [α =
R (486) / R (589)] was measured by a polarization microscope using a quarter wave plate corresponding to monochromatic light of 486 nm and 589 nm.

Example 1 To 40 parts of polyether urethane acrylate (refractive index 1.460) having an average molecular weight of about 6000 obtained by the reaction of polypropylene glycol, hexamethylene diisocyanate and 2-hydroxyethyl acrylate, 2,4 30 parts of 6-tribromophenyl acrylate (refractive index 1.576), 30 parts of 2-hydroxy-3-phenoxypropyl acrylate (refractive index 1.52)
6) and 1.5 parts of 2-hydroxy-2-methylpropiophenone as a photopolymerization initiator were added and mixed to prepare a photopolymerizable composition. This composition was applied to a polyethylene terephthalate film having a thickness of 188 μm, irradiated with ultraviolet rays at an irradiation angle of 17 ° by the apparatus shown in FIGS. 1 and 2, and then peeled from the polyethylene terephthalate film to prepare a light control plate. . In the figure, 1 is 80 W /
cm rod-shaped high-pressure mercury lamp, 2 light-shielding plate, 3 conveyor, 4 188 μm polyethylene terephthalate film coated with the composition for light control plate, and 5 the ultraviolet irradiation angle in this example. The thickness of this light control plate is 2
05 μm, domain spacing 3 μm, maximum haze value 7
The scattering angle range defined by 5% and haze value of 30% or more is 6 degrees to
It was 40 degrees.

A retardation film (trade name Sumikalite SEF-360428 manufactured by Sumitomo Chemical Co., Ltd.) prepared by uniaxially stretching a solvent cast film of polycarbonate was prepared. (Retardation = 380 nm, α = 1.0
6)

A 250 μm-thick acrylic sheet (Technoloy HG, manufactured by Sumitomo Chemical Co., Ltd.) on the surface of which an antireflection layer composed of a multi-layered inorganic dielectric thin film was formed was attached to a light control plate via an adhesive. In addition, the iodine-based polarizing film (Sumikaran SK-1842AP) is arranged such that the scattering direction of the light control plate and the absorption axis of the polarizing film are parallel to each other via the adhesive.
7, a Sumitomo Chemical Co., Ltd.), and a retardation film so that the slow axis of the retardation film is 25 degrees with respect to the absorption axis of the polarizing film via the adhesive of the polarizing film. An optical film (structure: antireflection layer / acrylic sheet / light control plate [0 °] / polarizing film / retardation film [25 °]) was obtained by laminating.

This optical film was used for SM-FTN-LCD by using acrylic adhesive on the upper side of SM-FTN-LCD mounted on a word processor (trade name: OASYS 30LX-401 manufactured by Fujitsu Limited).
The polarizing film was arranged so that the absorption axis of the polarizing film was 90 degrees when viewed from the upper side of the panel with reference to the long side of. (SM-F
The scattering direction of the light control plate is 9 with respect to the long side of the TN-LCD.
The 0 ° direction and the slow axis of the retardation film are 115 °. ) Also, using an acrylic adhesive on the lower side of the SM-FTN-LCD, the absorption axis of the film is 0 when viewed from the lower side of the panel with reference to the long side of the SM-FTN-LCD.
And the slow axis of the retardation film was arranged to be 115 degrees. When the liquid crystal display device thus obtained was visually observed, it had good viewing angle characteristics not only in the horizontal direction but also in the upward direction.

Example 2 The photopolymerizable composition used in Example 1 was applied to a 188 μm polyethylene terephthalate film, and the composition shown in FIGS.
A light control plate was produced by irradiating ultraviolet rays at an irradiation angle of 25 degrees by the apparatus shown in FIG. The thickness of this light control plate is 162 μm
The maximum haze value was 82%, and the scattering angle range defined by a haze value of 30% or more was 4 degrees to 47 degrees. The photopolymerizable composition used in Example 1 was further applied onto the above-mentioned light control plate prepared on a polyethylene terephthalate film, and ultraviolet rays were emitted at an irradiation angle of -35 by the apparatus shown in FIGS. 1 and 2.
After irradiating the film at a certain degree, it was peeled from the polyethylene terephthalate film to prepare a two-layer light control plate. The thickness of the two-layer light control plate is 326 μm,
The domain interval is 3 μm, the maximum haze value is 82%, and the scattering angle range defined by the haze value of 30% or more is −13 degrees to −47.
And 4 to 47 degrees.

The polycarbonate film formed by the solvent casting method is uniaxially stretched by the tenter stretching method according to the method of Japanese Patent Application No. 6-31669 (thickness = 60).
μm, retardation = 240 nm, α = 1.0
6) Then, a biaxially stretched polycarbonate film is laminated on one side using an acrylic pressure-sensitive adhesive, and the laminated body is 165
Angle relaxation of the retardation by heat-relaxing at 2 ° C (2% shrinking in the stretching axis direction of the uniaxially stretched film and 4% shrinking in the direction orthogonal to the stretching axis by heat relaxation), and then peeling and removing the biaxially stretched polycarbonate film A retardation film A having a small property was obtained. (Thickness 62 μm, Retardation = 540 nm, α = 1.06) Moreover, the cellulose diacetate film formed by the solvent casting method was stretched by the longitudinal uniaxial stretching method to obtain a retardation film B. (Thickness 126 μm, Retardation = 2
25 nm, α = 1.00) Retardation film A and retardation film B were laminated using an acrylic pressure-sensitive adhesive so that their slow axes were orthogonal to each other, and retardation = 315 nm, α = 1.10. A retardation film was obtained.

An iodine-based polarizing film (SP-1852AP7-AG1, manufactured by Sumitomo Chemical Co., Ltd.) having an antiglare layer formed on the surface of the light control plate with an adhesive is used so that the scattering direction of the light controlling plate is relative to the absorption axis of the polarizing film. Laminated on a two-layered light control plate so as to have directions of 0 ° and 180 °, and further, via a pressure-sensitive adhesive, so that the slow axis of the retardation film was 25 ° with respect to the absorption axis of the polarizing film. An optical film (structure: anti-glare layer / polarizing film / light control plate [0 °] / light control plate [180 °] / retardation film [25 °]) was obtained by sticking to a retardation film. This optical film has the functions of a light control plate, a retardation film and a polarizing film, and is effective in improving the viewing angle characteristics of a liquid crystal display device.

[Brief description of drawings]

FIG. 1 is a side view of an example of an ultraviolet irradiation device used in the present invention.

FIG. 2 is a perspective view of an example of an ultraviolet irradiation device used in the present invention.

FIG. 3 is a diagram showing a scattering direction of a light control plate with respect to an absorption axis of a polarizing film and a slow axis direction in which a phase difference is filled.

4 is a diagram showing the absorption axis direction of the polarizing film, the scattering direction of the light control plate, and the slow axis direction of the retardation film for the SM-FTN-LCD of Example 1. FIG.

[Explanation of symbols]

1 bar-shaped UV lamp 2 light-shielding plate 3 conveyor 4 polyethylene terephthalate film coated with composition for light control plate 5 irradiation angle 11 scattering direction of light control plate 12 slow-axis direction in film plane of retardation film 13 of polarizing film Absorption axis direction 14 Angle of the slow axis in the film plane of the retardation film with respect to the absorption axis of the polarizing film 15 Angle of the slow axis in the film plane of the retardation film with respect to the long side of SM-FTN-LCD 16 SM-FTN -The absorption axis angle of the polarizing film with respect to the long side of the LCD 20 The long side of the SM-FTN-LCD

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Takemura 2-10-1 Tsukahara, Takatsuki-shi, Osaka Sumitomo Chemical Co., Ltd.

Claims (10)

[Claims] 1. A light control plate obtained by irradiating ultraviolet rays after (a) forming a film-like composition containing two or more kinds of photopolymerizable monomers and / or oligomers having different refractive indexes from each other. An optical film formed by laminating at least one sheet, (b) at least one retardation film made of a thermoplastic resin, and (c) a polarizing film. 2. The optical film according to claim 1, wherein the composition contains a compound having a refractive index different from that of a photopolymerizable monomer or oligomer and having no photopolymerizability. 3. The optical film according to claim 1, wherein the difference in the refractive index of at least two kinds of the photopolymerizable monomer and / or oligomer is 0.01 or more. 4. The light control plate has a domain interval of 1 μm to 2
The optical film according to claim 1, which is a 0 μm refractive index modulation type light control plate. 5. The light control plate is a light control plate having a light ray incident angle region having a light haze value of 30% or more and a light ray incident angle region having a haze value of less than 30%. Item 1. The optical film according to Item 1 or 4. 6. The optical film according to claim 5, which has a maximum haze value of 30% to 85% in a light ray incident angle region showing a light ray scattering ability. 7. The optical film according to claim 1, wherein the retardation film is a thermoplastic resin having positive refractive index anisotropy. 8. The retardation film has a wavelength of 486n with respect to a retardation value R (589) at a wavelength of 589nm.
Ratio of retardation value R (486) in m α [α = R
The optical film according to claim 1, which is a thermoplastic resin having a positive refractive index anisotropy of (486) / R (589)] of 1.07 or more. 9. At least one of two glass substrates having an electrode is transparent, has positive dielectric anisotropy between the two glass substrates, and has a twist angle of 60 to 120 degrees. In a liquid crystal cell in which a certain nematic liquid crystal layer is arranged,
A liquid crystal display device comprising the optical film according to claim 1 disposed above and / or below a liquid crystal cell. 10. At least one of two glass substrates having an electrode is transparent, has a positive dielectric anisotropy between the two glass substrates, and has a twist angle of 180 to 270.
A liquid crystal display in which the optical film according to claim 1 is arranged on the upper side and / or the lower side of the liquid crystal cell in a liquid crystal cell in which a nematic liquid crystal layer having a certain degree is arranged.