JP2692033B2 - Method for producing optical compensation film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an optical compensation film, and more particularly to a method for producing an optical compensation film which is useful for improving display contrast and viewing angle characteristics of a display color of a display device using a TN type liquid crystal. .

[0002]

2. Description of the Related Art A CRT which is a mainstream display device of OA equipment such as a Japanese word processor and a desktop personal computer.
Has been converted to a liquid crystal display element having great advantages such as thin and light weight and low power consumption. Most of the liquid crystal display elements (hereinafter, referred to as LCDs) that are currently widely used use twisted nematic liquid crystals. Display methods using such a liquid crystal can be roughly classified into two methods, a birefringence mode and an optical rotation mode.

An LCD using a birefringence mode has a liquid crystal molecule array twisted by 90 ° or more and has steep electro-optical characteristics, and therefore has a simple matrix-like electrode without active elements (thin film transistor or diode). With the structure, a large capacity display can be obtained by time-division driving. However, an LCD using this birefringence mode has a slow response speed (several hundreds of milliseconds) and has a drawback that gradation display is difficult. Therefore, a liquid crystal display element (TFT-LCD or MIM) using an active element is used.
-It does not exceed the display performance of LCD etc.

In the TFT-LCD and the MIM-LCD, an optical rotation mode display mode (TN type liquid crystal display element) in which the alignment state of liquid crystal molecules is twisted by 90 ° is used. This display method has a fast response speed (several tens of milliseconds), can easily obtain a white display, and has a high display contrast. Therefore, this display method is the most effective method for improving the image quality as compared with LCDs of other methods. is there. However, since the twisted nematic liquid crystal is used, there is a problem in viewing angle characteristics such that a display color and a display contrast change depending on a viewing direction due to a principle of a display method, and the display performance of a CRT cannot be exceeded.

JP-A-4-229828, JP-A-4-4-2
As disclosed in Japanese Patent No. 58923, a method has been proposed in which a viewing angle is increased by disposing a retardation film between a pair of polarizing plates and a TN type liquid crystal cell. The retardation film proposed in the above-mentioned patent publication has a retardation of almost zero in the direction perpendicular to the liquid crystal cell, and does not exert any optical action from the front.
A phase difference is developed when tilted, and the phase difference developed in the liquid crystal cell is to be compensated. However, even with these methods, the improvement of the viewing angle of LCD is still insufficient,
Further improvements are desired. In particular, when it is considered to be mounted on a vehicle or as an alternative to a CRT, a phenomenon in which a display image is colored (coloring phenomenon) or black and white is inverted when the screen is tilted 20 degrees to 30 degrees from the screen normal direction to the normal viewing angle direction and the horizontal direction A phenomenon (reversal phenomenon) is observed, and the current situation is that the viewing angle characteristics currently required cannot be met at all.

In Japanese Patent Application Laid-Open Nos. 4-366808 and 4-366809, a viewing angle is improved by using a liquid crystal cell containing a chiral nematic liquid crystal having an inclined optical axis as a retardation film. This is a two-layer liquid crystal system, which is expensive and very heavy. Further, in JP-A-4-113301 and JP-A-5-80323,
For liquid crystal cells, a method of using a retardation film whose optical axis is inclined has been proposed, but since the uniaxial polycarbonate is used by obliquely slicing, it is difficult to obtain a large area retardation film, There are problems that the cost is high and the effect of improving the viewing angle is still insufficient. Further, JP-A-5-157913 and EP057.
6304A1 discloses a method of using a retardation film having an optical axis inclined by performing special stretching on polycarbonate, but it is still difficult to obtain a large area retardation film at low cost. .

Further, Japanese Patent Laid-Open No. 215921/1993 proposes a method of optically compensating an LCD with a birefringent plate in which a rod-shaped compound exhibiting liquid crystal property at the time of curing is sandwiched between a pair of substrates subjected to alignment treatment. However, this plan is no different from the so-called double-cell type compensator that has been proposed in the past, and it causes a great increase in cost and is practically unsuitable for mass production. Further, as long as a rod-shaped compound is used, the birefringent plate has a T
It is impossible to improve the omnidirectional viewing angle of N-type LCD. Also,
JP-A-3-9326 and JP-A-3-291601 describe a plan to apply a polymer liquid crystal to a film-shaped substrate on which an alignment film is provided to form an optical compensator for LCD. , It is impossible to align molecules obliquely by this method, so TN LC
It is impossible to improve the omnidirectional viewing angle of D.

Therefore, the present inventor has filed Japanese Patent Application No. Hei 5-23653.
In No. 9, an optical compensation film was proposed in which a layer containing a discotic compound was oriented on an orientation film provided on a plane orientation transparent film. In this optical compensation film, the discotic compound has an optically negative uniaxial property and an optical axis inclined from the normal direction of the film due to the fact that the compound is oriented on the orientation film to form a monodomain. , Due to the interaction with the characteristic that the optical axis is aligned with the ray direction of the film due to the optically negative uniaxiality due to the plane-oriented transparent support, there is no optical axis as a whole, but the absolute value of the retardation It has an optical property that it has a minimum value and its direction is tilted from the radial direction of the film, and further improves the viewing angle in all directions compared to the conventionally proposed optical compensation sheet for TFT. be able to. However, the layer containing the oriented discotic compound itself has low mechanical strength and is sticky, so if something touches it, the orientation of the discotic compound will be disturbed or the discotic compound will separate from the layer. There was a problem such as sticking. Further, an adhesive is applied to the layer containing the discotic compound for bonding with an LCD substrate or a polarizing plate, or water,
There is also a problem that orientation is disturbed when oil or solvent is applied.

[0009]

The object of the present invention is to have a layer containing an oriented discotic compound, which has improved surface stickiness and improved durability against pressure-sensitive adhesives, water and oil solvents, It is to provide a method for producing an optical compensation film having optical anisotropy.

[0010]

According to the present invention, an alignment film is provided on a transparent support, a liquid containing a discotic liquid crystal is applied onto the alignment film and dried, and then the discotic liquid crystal is subjected to an alignment treatment. Then, a protective layer is provided on the layer containing the aligned discotic liquid crystal, and a method for producing an optical compensation film; and an alignment film is provided on a transparent support, and the discotic film is provided on the alignment film. After applying a liquid crystal-containing liquid and drying the liquid crystal, the discotic liquid crystal is subjected to an alignment treatment to fix the alignment state, and then a protective layer is placed on the layer containing the aligned and fixed discotic liquid crystal. And a method for producing an optical compensation film.

Hereinafter, the present invention will be described in detail. First, the usefulness of the optical compensation film of the present invention will be described with reference to the drawings using a TN type LCD as an example. 1 and 2 show polarization states of light propagating in a liquid crystal cell when a sufficient voltage equal to or higher than a threshold voltage is applied to the liquid crystal cell. Since the transmittance characteristic of light particularly when a voltage is applied greatly contributes to the viewing angle characteristic of the contrast, a case where a voltage is applied will be described as an example. FIG. 1 is a diagram illustrating a polarization state of light when the light is vertically incident on the liquid crystal cell. When the natural light L0 is perpendicularly incident on the polarizing plate A having the polarizing axis PA, the light transmitted through the polarizing plate PA becomes linearly polarized light L1.

When the arrangement state of the liquid crystal molecules when a sufficient voltage is applied to the TN type liquid crystal cell is schematically represented by one liquid crystal molecule, LC in the schematic diagram is obtained. When modeled by liquid crystal molecules in a liquid crystal cell, if the molecular long axis of LC in the schematic diagram is parallel to the path of light, a difference in refractive index occurs on the incident surface (in a plane perpendicular to the path of light). Therefore, even when the light passes through the liquid crystal cell, it propagates as linearly polarized light. Polarization axis P of polarizing plate B
When B is set perpendicular to the polarization axis PA of the polarizing plate A, the linearly polarized light L2 that has passed through the liquid crystal cell cannot pass through the polarizing plate B and is in a dark state.

FIG. 2 is a diagram showing the polarization state of light when the light is obliquely incident on the liquid crystal cell. Natural light L of incident light
When 0 is obliquely incident, the polarized light L1 transmitted through the polarizing plate A becomes substantially linearly polarized light. (In practice, it becomes elliptically polarized light due to the characteristics of the polarizing plate). In this case, the refractive index anisotropy of the liquid crystal causes a difference in the refractive index on the incident surface of the liquid crystal cell, and the light L2 transmitted through the liquid crystal cell is elliptically polarized light and is not completely blocked by the polarizing plate B. As described above, in the oblique incidence, the blocking of light in the dark state becomes insufficient, and the contrast is greatly reduced, which is not preferable.

An object of the present invention is to provide an optical compensator capable of preventing such a decrease in contrast at oblique incidence and improving viewing angle characteristics. FIG. 3 shows a usage example of the optical compensation sheet manufactured according to the present invention. An optical compensation film RF1 having a minimum absolute value of retardation is arranged between the polarizing plate A and the liquid crystal cell TNC in a direction inclined from the normal direction of the liquid crystal cell. The optical compensation film RF1 is a birefringent body in which the phase difference increases as the incident angle of light increases in this direction. Further, an optical compensation film RF2 having the same optical characteristics as the optical film RF1 is provided between the polarizing plate B and the liquid crystal cell TNC.
Is arranged. A liquid crystal display device having such a structure is shown in FIG.
When the natural light L0 is obliquely incident as in the case of 1, the optical modulation described below occurs. First, it is converted into linearly polarized light L1 by the polarizing plate A, and is modulated into elliptically polarized light L3 by the phase delay action when passing through the optical compensation film RF1. Next, when it passes through the liquid crystal cell TNC, it is modulated into elliptically polarized light L4 having an opposite phase, and when it further passes through the optical compensation film RF2, it is returned to the original linearly polarized light L5 by the phase delaying action. By such an operation, the same transmittance of the natural light L0 can be obtained even at various oblique incidences, and a liquid crystal display device capable of high-quality display without dependence on viewing angle can be obtained.

It is presumed as follows that the viewing angle of the liquid crystal display device can be greatly improved by the optical compensation film produced by the present invention. TN-LCD
Many of them use the normally white mode. In this mode, as the viewing angle increases,
The transmittance of light from the black display portion remarkably increases, resulting in a sharp drop in contrast. The black display is a state when a voltage is applied. At this time, the liquid crystal molecules in the TN liquid crystal cell are arranged as shown in the model of FIG. When the arrangement of the liquid crystal molecules is approximated by an optically positive uniaxial refractive index ellipsoid, it becomes as shown in FIG. 4B, and the optical axis of the TN type liquid crystal cell is slightly tilted from the direction normal to the cell surface. Two positive uniaxial optical anisotropic bodies and two positive uniaxial optical anisotropic bodies whose optical axes are oriented in the same direction as the normal direction, for a total of 4
It can be regarded as a laminate of sheets.

If the liquid crystal cell can be regarded as a laminated body of four positive uniaxial optically anisotropic bodies, in order to compensate for it, a negative uniaxial optical element having the same combination of the optical axis inclination angles as that of the laminated body is used. It is preferable to use four anisotropic bodies. In the case of the present invention,
A layer containing a disk-shaped compound oriented as a negative uniaxial optical anisotropic body in which the optical axis is slightly inclined from the direction normal to the cell surface is acting, and the optical axis is in the same direction as the normal direction to the cell surface. That is, the plane-oriented transparent support acts as a negative uniaxial optically anisotropic body facing toward. For these reasons, it is estimated that the optical compensation film of the present invention has significantly improved the viewing angle characteristics.

The transparent support used in the optical compensation film of the present invention is required to have a good light transmittance as well as a plane orientation. The plane orientation referred to in the present invention is a state in which the relationship of triaxial refractive index of the film used as the support satisfies nx = ny> nz. However, nx and ny are the refractive indices in the optical axis direction orthogonal to each other in the film plane, and nz is the refractive index in the film thickness direction. Further, the values of nx and ny do not have to be exactly the same, and it is sufficient if they are almost equal. Specifically, there is no practical problem if | nx-ny | / | nx-nz | ≦ 0.2. Further, when the thickness of the base film is d, it is preferable that the condition of 20 ≦ n · d ≦ 300 (nm) is satisfied. More preferably 3
0 ≦ n · d ≦ 150. However, n = (nx + n
y) / 2-nz. Specifically, a film formed of a material having a small intrinsic birefringence value, which is sold under the trade name of ZEONEX (Nippon Zeon), ARTON (Nippon Synthetic Rubber), Fujitac (Fuji Photo Film Co., Ltd.) is preferable. However, even with materials having a large intrinsic birefringence value such as polycarbonate, polyarylate, polysulfone, and polyethersulfone, by controlling the molecular orientation during film formation, a plane-oriented film with n · d = 20 to 300 nm can be obtained. It is also possible to form them, and they can be suitably used.

The discotic compound in the present invention includes discotic liquid crystals listed below, and other low molecular weight compounds, or reaction products of discotic liquid crystals which no longer exhibit liquid crystallinity due to reaction with a polymer. As described above, the molecule itself means a compound having optically negative uniaxiality.

[0019]

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[0020]

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[0021]

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The term "optically negative uniaxiality" used to define the discotic compound in the present invention means the triaxial refractive index of the compound,
When nx, ny, and nz are set in the ascending order, nx
It has a relationship of <ny = nz. Therefore, it has a characteristic that the refractive index in the optical axis direction is the smallest. However, the values of ny and nz do not have to be exactly equal, and it is sufficient if they are almost equal. Specifically, if | ny-nz | / | ny-nx | ≦ 0.2, there is no practical problem. Further, as a condition for significantly improving the viewing angle characteristics of the TFT or TN type liquid crystal cell, the optical axis of the layer containing the discotic compound has an inclination β from the normal direction of the film surface of 5 ° to 50 °. Preferably 10
More preferably, the degree is 40 degrees. Further, the thickness of the liquid crystal layer is a
Then, it is preferable that the condition of 50 ≦ Δn′a ≦ 300 (nm) is satisfied. Where Δn ′ = (n
y + nz) / 2-nx.

When the discotic compound in the present invention is a discotic liquid crystal, the layer containing the discotic liquid crystal is made to have an optically negative uniaxial property and the optical axis is tilted by 5 to 50 ° from the normal direction of the film. Alignment treatment is required for alignment. For example, simply rubbing the surface of the support,
There is also a combination of a discotic liquid crystal and a support that can provide effective alignment just by coating on it, but the most versatile method is to use an alignment film. As the alignment film, an inorganic oblique deposition film or an alignment film obtained by rubbing a specific organic polymer film corresponds to this. Further, a thin film in which molecules are isomerized by light, such as an LB film made of an azobenzene derivative, and in which molecules are arranged with directionality and uniformity is also applicable.

A typical example of the organic alignment film is a polyimide film. This is applied by coating a polyamic acid (for example, SE-7210 manufactured by Nissan Chemical Industries, Ltd.) on the support surface.
By rubbing after firing at 00 ° C to 300 ° C,
The discotic liquid crystal can be aligned. Further, a coating film of an alkyl chain-modified Poval (for example, MP203 and R1130 manufactured by Kuraray Co., Ltd.) need not be baked, and the orientation ability can be imparted only by rubbing. In addition, most of the organic polymer films forming a hydrophobic surface such as polyvinyl butyral and polymethylmethacrylate can impart the discotic liquid crystal alignment ability by rubbing the surface. A typical example of the inorganic oblique deposition film is a SiO oblique deposition film. In this method, SiO evaporation particles are applied obliquely to a base film surface in a vacuum chamber, and an obliquely deposited film having a thickness of about 20 to 200 nm is formed to form an alignment film. When the discotic liquid crystal is oriented by the deposited film, the optical axis of the liquid crystal layer is directed to a specific direction on a plane perpendicular to the base film surface, including the trajectory of the deposited SiO particles.

The above-mentioned alignment film has the function of determining the alignment direction of the discotic liquid crystal molecules provided thereon.
However, since the alignment of the discotic liquid crystal depends on the alignment film, it is necessary to optimize the combination. next,
The discotic liquid crystal molecules that have once been oriented are oriented at an angle θ with respect to the support surface, but in the one-component system, the angle of oblique orientation does not change much depending on the type of the alignment film, and may take a value specific to the discotic liquid crystal molecules. Many. Also,
When two or more kinds of discotic liquid crystal molecules are mixed, the tilt angle can be adjusted within a certain range by the mixing ratio. Therefore,
For controlling the tilt angle of the oblique alignment, it is effective to select a discotic liquid crystal species, and further to mix two or more discotic liquid crystal molecules.

Other methods of orienting the discotic compound coated on the substrate obliquely include magnetic field orientation and electric field orientation. In this method, after the discotic compound is coated on the support, the discotic compound can be obliquely oriented at a desired angle by using a magnetic field, an electric field or the like.

A colorless and transparent polymer is used for the protective layer in the present invention. However, in order to prevent stickiness, the Tg of the polymer is preferably room temperature (25 ° C.) or higher. When the protective layer is provided by coating, the polymer is preferably soluble in water or a solvent, and examples of the water-soluble polymer include proteins such as gelatin and albumin, cellulose derivatives such as methyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose, and pullulan. , Sugar derivatives such as xanthan gum, pectin, sodium alginate, starch, polyvinyl alcohol, polyethylene glycol, poly-N-methylpyrrolidone, polyacrylamide, polyacrylic acid copolymer, polymethacrylic acid copolymer, polyvinylbenzenesulfonic acid copolymer Examples thereof include synthetic polymers such as coalesce and hydrolysates of polymaleic anhydride copolymers.

Examples of the solvent-soluble polymer include cellulose butyrate phthalate, triacetyl cellulose, diacetyl cellulose, and other cellulose derivatives, polystyrene, polymethylmethacrylate, poly-styrene-vinyltoluene, polybutylmethacrylate, polycarbonate, poly Examples thereof include synthetic polymers such as vinyl chloride and polyvinyl acetate.

Also, instead of coating, polyethylene,
The protective layer can be provided by laminating a thin film such as polypropylene or polyvinylidene chloride.

These polymers can be crosslinked to further improve the mechanical strength of the protective layer. In addition to these polymers, the protective layer may contain a matting agent for preventing adhesion, a slipping agent for improving slipperiness, an antistatic agent for preventing static electricity, and the like.

In the optical compensation film of the present invention, an alignment film is provided on a transparent support, and if necessary, a rubbing treatment is performed, and then a layer containing a discotic liquid crystal is applied thereon,
After drying, it is heated to orient the discotic liquid crystal, and when the discotic liquid crystal has a reactive double bond, the previously added light or thermal polymerization initiator is decomposed by UV irradiation or heating. It is preferable to polymerize the discotic liquid crystals with each other. It can be prepared by cooling and then coating a protective layer containing a polymer on it, or laminating a thin film of a polymer, and installing the protective layer.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments. Example 1 A 127 μm thick film of triacetyl cellulose (where the refractive index in two orthogonal directions in the film plane is nx, ny, the refractive index nz in the thickness direction, and the thickness d = 127 μm, (nx-ny) × d = 20 (nm), {(nx + ny) / 2-nz} × d = 95 (nm)) is used as a support, and an alkyl-modified Poval (MP302 manufactured by Kuraray Co., Ltd.) is used as an alignment film on the support. 2 μm
It was applied so as to be thick. After rubbing this with a rubbing machine to give orientation ability, the discotic liquid crystal material obtained by mixing the discotic liquid crystals TE-8 and TE-8 at a blending ratio of 4: 1 was dissolved in methyl ethyl ketone to 10 wt%. The solution was applied by a spin coater at 3000 rpm to form a film having a layer containing a discotic liquid crystal having a thickness of 1 μm. After this film was placed in a constant temperature bath set at 145 ° C. for 5 minutes, it was brought into contact with a metal surface set at 10 to 20 ° C. and rapidly cooled to orient the discotic liquid crystal layer to have optical anisotropy. An optical compensation film (X) of Comparative Example was prepared. An aqueous solution containing 5% of 680 gelatin and 0.05% of polyoxyethylene nonylphenyl ether was applied to this film by a spin coater to form a protective layer having a thickness of 1 μm, thereby preparing an optical compensation film (A) of the present invention. .

Example 2 An optical compensation film (B) of the present invention was prepared in the same manner as in Example 1 except that methyl cellulose was used instead of 680 gelatin.

[0034]

[Table 1]

Example 3 The same triacetyl cellulose as in Example 1 was used as a support, and an alkyl-modified Poval (MP302 manufactured by Kuraray Co., Ltd.) as an alignment film was applied thereon to a thickness of 2 μm. After rubbing this with a rubbing machine to give orientation ability, 10 wt% of the discotic liquid crystal TE-8 was added.
%, And Irgacure 907 (trade name, manufactured by Ciba-Geigy Co., Ltd.) of 0.1 wt% was dissolved in methyl ethyl ketone to obtain a liquid of 3200 r using a spin coater.
pm was applied to make a film with a layer containing a 1 μ thick discotic liquid crystal. This film 150
After being placed in a constant temperature bath set at 0 ° C. for 5 minutes, a mercury lamp (400 watts) was irradiated for 2 minutes under the same conditions and allowed to cool to room temperature, whereby an optical compensation film of a comparative example having optical anisotropy ( Y) was prepared. An aqueous solution containing 5% of 680 gelatin and 0.05% of polyoxyethylene nonylphenyl ether was applied to this film by a spin coater to form a protective layer having a thickness of 1 μm, thereby preparing an optical compensation film (C) of the present invention. .

The optical compensation film (A) of the present invention,
(B), (C) and the optical film (X) of Comparative Example,
With respect to (Y), the retardation was measured in all directions, the direction in which the absolute value was the minimum was determined, and summarized in Table-1. Also, after sticking an adhesive tape on these films and leaving it at room temperature for 24 hours, peel off the adhesive tape and observe what has adhered to the adhesive. Similarly, for these films, the absolute value of the retardation is the minimum. Then, the directions were calculated and summarized in Table-1.

[0037]

As is apparent from Table 1, in the optical film having no protective layer, the layer containing the discotic liquid crystal was easily broken by the adhesive tape, and a part of the layer adhered to the side surface of the adhesive tape, leaving the remaining discotic film. The orientation of the liquid crystal layer was also disturbed. On the other hand, in the optical compensation film of the present invention having a protective layer containing gelatin or methylcellulose, the orientation is disturbed by the adhesive tape, and the discotic liquid crystal layer does not adhere to the adhesive tape side,
It was found to have excellent durability.

The product of the difference in refractive index between the extraordinary ray and the ordinary ray of the liquid crystal and the gap size of the liquid crystal cell is 510 nm, and the twist angle is 87.
The optical compensation films of Examples and Comparative Examples were mounted on the TN type liquid crystal cell at 0 ° as shown in FIG.
The angle dependence of the transmittance (T) of V in a 40 Hz rectangular wave was measured by LCD-5000 manufactured by Otsuka Electronics. Contrast ratio (T _1V / T _5V ) from the direction normal to the surface of the liquid crystal cell
The angle up to the position showing 10 was defined as the viewing angle, and the viewing angles in the vertical and horizontal directions were obtained. Comparing this with the case of only the TN type liquid crystal cell in which no optical compensation sheet is attached, the viewing angle is obviously wider by 40 ° in the vertical direction and 60 ° or more in the horizontal direction when the optical compensation film is used. It was

[Brief description of the drawings]

FIG. 1 is a diagram showing a polarization state of light when light is vertically incident on a liquid crystal cell.

FIG. 2 is a diagram showing a polarization state of light when light obliquely enters a liquid crystal cell.

FIG. 3 is a diagram illustrating an example of use of an optical compensation sheet.

4A and 4B are a liquid crystal molecule alignment model diagram when a voltage is applied to an N liquid crystal cell, and a diagram in which optical characteristics thereof are approximated.

FIG. 5 is a diagram showing a relationship between a polarization axis of a polarizing plate, a rubbing direction of a liquid crystal cell, and a rubbing direction of an alignment film of an optical compensation film when measuring viewing angle characteristics in Examples and Comparative Examples.

[Explanation of symbols]

TNC: TN type liquid crystal cell A, B: polarizing plate PA, PB: polarization axis L0: natural light L1, L5: linearly polarized light L2: modulated light after passing through the liquid crystal cell L3, L4: elliptically polarized light LC: TN type liquid crystal cell State of liquid crystal molecules when voltage is sufficiently applied to RF1, RF2: optical compensation sheet BL: backlight R1, R2: rubbing direction of optical compensation sheet

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-2-111918 (JP, A) JP-A-2-304526 (JP, A) JP-A-3-291601 (JP, A) JP-A-3- 291620 (JP, A) JP 5-196815 (JP, A) JP 5-61039 (JP, A) JP 4-333019 (JP, A) JP 2640083 (JP, B2) JP 2587398 (JP , B2) Patent 2641086 (JP, B2)

Claims (2)

(57) [Claims] 1. A alignment film provided on the transparent support, the liquid was applied containing a discotic liquid crystal on the alignment film, after drying, the discotic liquid crystal alignment treatment, and then oriented discotic liquid A method for producing an optical compensation film, which comprises disposing a protective layer on the layer containing a. Wherein providing the alignment film on the transparent support, the liquid was applied containing a discotic liquid crystal on the alignment film, dried, and then the alignment process the discotic liquid crystal, to fix the orientation state After that, a protective layer is placed on the layer containing the aligned and fixed discotic liquid crystal, and the method for producing an optical compensation film.