JP3473266B2 - Laminated sheet and twisted nematic liquid crystal display using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Liquid crystal display devices are being used in portable televisions, notebook personal computers, etc. due to their features such as light weight, thin shape, and low power consumption. Among them, TN type liquid crystal driven by active matrix which excels in image quality. The adoption of display devices (hereinafter referred to as AM-TN-LCDs) has greatly increased. AM-TN-LCD has come to be able to obtain image quality exceeding CRT when viewed from the front due to technical improvements so far, but decreases in contrast and changes in hue when viewed from an oblique direction. Since such a viewing angle characteristic is not sufficient as compared with a CRT, this improvement is strongly desired.

The viewing angle characteristics of the AM-TN-LCD are mainly due to the angle dependence of birefringence of the oriented liquid crystal in the liquid crystal cell. Due to this birefringence, as the angle from the front increases. At the same time that the contrast is lowered, when gradation display is performed, gradation inversion occurs in which the gradations are interchanged, and the hue changes greatly, making the display difficult to see. In order to solve this, studies have been widely conducted to introduce an optical compensation layer such as a retardation plate to compensate for the angle dependence of birefringence and improve the viewing angle characteristics. For example, Japanese Unexamined Patent Publication No. 6-331979 discloses a method of arranging a compensating layer having negative refractive index anisotropy between a pair of polarizing plates, and Japanese Unexamined Patent Publication No. 6-250166. , Using an optical retardation element in which a twisted nematic liquid crystal twisted in a spiral shape so as to have substantially negative refractive index anisotropy is further oriented so that its spiral axis is inclined with respect to a substrate A method is disclosed. Further, Japanese Patent Application Laid-Open No. 6-214116 discloses a method of using an optical anisotropic element having negative refractive index anisotropy and having an optical axis inclined by 10 to 40 degrees with respect to the sheet surface. There is.

[0004]

[Problems to be Solved by the Invention]
Although the viewing angle characteristics of the M-TN-LCD are greatly improved, even if these methods are used, the improvement of gradation inversion is not always sufficient in a specific direction, particularly in the main viewing angle direction. With respect to, the improvement of the viewing angle is desired.

[0005]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that at least one light control plate and at least one compound having negative refractive index anisotropy are selected. The laminated sheet in which at least one retardation film, which has an asymmetrical change with respect to the normal direction of the film when tilted with the slow axis included as the tilt axis and whose retardation is measured, and a polarizing film are laminated, is a liquid crystal. They have found that they have an effect of improving the viewing angle of a display device, and have completed the present invention.

That is, the present invention is (1) at least one sheet obtained by irradiating with ultraviolet rays after forming a composition containing two or more kinds of photopolymerizable monomers or oligomers having different refractive indexes into a film. Of the light control plate of No. 1, which contains at least one compound having negative refractive index anisotropy, shows an asymmetric change with respect to the normal direction of the film when the retardation is measured by inclining with the slow axis as the inclining axis. At least one retardation film, and a laminated sheet characterized by laminating a polarizing film, (2) two or more kinds of photopolymerizable monomers or oligomers having mutually different refractive indices, and a refractive index different from these At least one light control plate obtained by irradiating with ultraviolet rays after forming a composition containing a compound having no photopolymerizability into a film, and at least one kind of negative refraction At least one retardation film, which contains a compound having anisotropy and changes asymmetrically with respect to the normal direction of the film when the retardation is measured by tilting with the slow axis as the tilt axis, and a polarizing film. A laminated sheet characterized by being laminated, and
(3) The present invention relates to a twisted nematic liquid crystal display device using any of these laminated sheets.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The light control plate used in the present invention is produced using a composition containing at least two types of photopolymerizable monomers and / or oligomers having mutually different refractive indexes.

Examples of these photopolymerizable monomers and oligomers are 2,4,6-tribromophenyl acrylate, tribromophenoxyethyl acrylate, and 2 as described in JP-A-7-64069. -Hydroxy-3-phenoxypropyl acrylate, tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, pentenyloxyethyl acrylate,
Examples thereof include phenyl carbitol acrylate, polyol polyacrylate, isocyanuric acid skeleton polyacrylate, melamine acrylate, hydantoin skeleton polyacrylate, and urethane acrylate.

As the photopolymerizable monomer and oligomer, two or more kinds having different refractive indexes are used.
Examples of the combination include two types selected from monomers, one type of monomer and one type of oligomer, two types selected from oligomer, and those obtained by further adding one or more types of monomers or oligomers. . In these combinations, it is preferable that at least two of them have a refractive index difference of 0.01 or more in order to obtain a necessary light scattering ability.

Further, in order to improve the curability of the above resin composition for a light control plate, it is preferable to use a photopolymerization initiator. Examples of the photopolymerization initiator include benzophenone, 2-hydroxy-2-methylpropiophenone, benzyl, Michler's ketone, and 2-chlorothioxanthone as exemplified in JP-A-7-64069. Furthermore, a filler having an average particle size of 0.05 to 20 μm is added to the resin composition for a light control plate in an amount of 0.01 to 20 μm.
It is also possible to mix 5 parts by weight and to add an ultraviolet absorber.

As described in JP-A-7-64069, the above composition is cured by a photo-curing device as shown in FIGS. 1 and 2 so that incident light having a specific angle can be selectively selected. It is possible to obtain a light control plate that scatters in the light. Also,
You may use a thermosetting mechanism together in the range which 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. With this method, it is possible to obtain a light control plate that selectively scatters incident light having a desired angle.

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 range (scattering angle) having a light ray scattering ability of 30% or more and a light ray scattering ability. It is preferable to have a light incident angle range other than that. Maximum haze value in the scattering angle range is 30-85%
Is preferable in terms of display clarity.

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

The light control plate used in the present invention is disclosed in Japanese Patent Application Laid-Open No.
As disclosed in JP-A-209637, when a composition containing a specific photopolymerizable monomer or oligomer is irradiated with ultraviolet rays, it is prepared by utilizing the property of photopolymerizing and curing while causing phase separation. According to this method, it is possible to manufacture a smooth refractive index modulation type light control plate having a domain interval of 1 to 20 μm without using a mask when irradiating ultraviolet rays. 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 is not reduced. In addition, unlike the phase grating, this light control plate does not have a regular structure, so that moire fringes do not occur. Furthermore, since this light control plate can be manufactured only by the step of irradiating the film-shaped composition with ultraviolet rays without using a mask, the manufacturing method is simple and the mass productivity is excellent.

With respect to the light scattering ability of the light control plate, the light scattering angle width can be controlled by the domain spacing of the light control plate, and the narrower the domain spacing, the wider the light scattering angle width. AM-TN-LCD
For the expansion of the viewing angle, a light control plate having a domain spacing of 1 to 20 μm is preferable, and a domain spacing of 1 to 2 μm is more preferable.

The light source used for photopolymerization and curing for producing a light control plate having a domain interval of 1 to 20 μm is not particularly limited as long as it emits ultraviolet rays that contribute to photopolymerization. In order to increase the light-scattering ability of the light control plate, when a light control plate having a narrow domain interval, for example, a domain interval of 1 to 2 μm is produced, the wavelength of the light irradiating the resin composition for the light control plate is set. It must be limited to 400 nm or less. However, the absorption wavelength range of the photopolymerization initiator is, for example, 200 to 500.
When the wavelength is limited to the wavelength range of nm, the wavelength range exceeding 500 nm does not contribute to photopolymerization and curing, and therefore the resin composition for a light control plate may be irradiated. Regarding the light scattering power of the light control plate, the narrower the domain spacing, the wider the light scattering angle width,
In order to narrow the domain interval, the wavelength of light with which the resin composition for a light control plate is irradiated may be limited to the lower wavelength side.

The shape of the light source is appropriately selected depending on the light control function required for the laminated film of the present invention. JP 7-2
When the light scattering power of the light control plate is desired to be equal in all directions, as illustrated in Japanese Patent No. 09637, it is most preferable to use parallel rays such as sunlight, but spherical or box-shaped, or lamp If the ratio of the length in the major axis direction to the length in the minor axis direction is 2: 1 or less, the same performance can be exhibited. A linear or rod-shaped light source is used as a preferable irradiation light source when the scattering property is provided only in one direction such as the vertical direction or the horizontal direction.

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

When the retardation is measured by including at least one compound having negative refractive index anisotropy and tilting with the slow axis as the tilt axis, a change asymmetric with respect to the normal direction of the film is observed. The retardation film can be obtained by orienting at least one compound having negative refractive index anisotropy so that the optical axis is tilted by 5 to 50 degrees with respect to the normal direction of the film. . The compound having negative refractive index anisotropy as used herein means that when oriented, it exhibits a negative refractive index anisotropy in which the refractive index in the optical axis direction is smaller than the average refractive index in a plane perpendicular to this. It is a compound. There is no particular limitation as long as it is a compound satisfying such characteristics,
An organic compound or an inorganic compound, a low molecular compound or a high molecular compound can be used.

As the organic low-molecular compound, discotic liquid crystal having a disk-shaped molecular structure or spiral pitch of 400 is used.
A cholesteric liquid crystal having a wavelength of nm or less is exemplified. As described in JP-A-6-214116, a method for orienting a discotic low-molecular liquid crystal such as a discotic liquid crystal in a polymer matrix, or as described in JP-A-8-5837. By using a method in which a discotic low-molecular liquid crystal such as a molecular discotic liquid crystal is tilt-aligned using a specific alignment film, a compound having a negative refractive index anisotropy can be obtained so that the optical axis is in the normal direction of the film. Against 5
It can be oriented to be tilted by -50 degrees. Examples of the discotic liquid crystal include those in which a straight-chain substituent such as an alkyl group, an alkoxy group, or a substituted benzoyloxy group is radially bonded to a mother nucleus having a planar structure such as triphenylene, torqcene, or benzene. Those having no absorption in the visible light region are preferable. The polymer used in the polymer matrix is not particularly limited as long as it has compatibility with the liquid crystal or can disperse the liquid crystal into a particle size that does not scatter light.

When a cholesteric liquid crystal is used,
As described in JP-A 6-250166, a method of orienting a low molecular weight or high molecular weight cholesteric liquid crystal so that its spiral axis is inclined with respect to the substrate can be adopted. Further, as the discotic liquid crystal, a method of using a polymer discotic liquid crystal having a mesogen having triphenylene, benzene or the like as a nucleus in a side chain or a main chain, or a low molecular discotic liquid crystal having a polymerizable functional group as a substituent It is also possible to use a method of orienting and then polymerizing and curing with ultraviolet rays or the like. Furthermore, even a low-molecular-weight organic compound that does not exhibit liquid crystallinity exhibits negative refractive index anisotropy by aligning with an electric field or magnetic field,
In addition, any material can be used as long as it can be tilted.

When an inorganic compound is used, it is possible to use a method in which a layer containing a swellable inorganic layered compound that can be dispersed in a solvent such as water is formed on a substrate capable of tilt orientation. Such a compound has a layered structure in which the unit crystal layers are stacked on top of each other, and the bond between the unit crystal layers is relatively weak, so that when the unit crystal layers become colloidal when dispersed in a dispersion medium, the unit crystal layers are separated from each other. Clay minerals, such as the smectite group, that can swell can be used. Among them, synthetic hectorite, which does not contain impurities and whose particle size is controlled to 1 μm or less, is preferably used in terms of transparency. These swellable inorganic layered compounds are preferably used as a mixture with a transparent resin soluble in the same solvent in order to improve mechanical properties such as prevention of cracking of the layer after film formation.

The compound having negative refractive index anisotropy as described above has an optical axis of 5 with respect to the normal direction of the film.
In order to obtain a film which is oriented so as to be inclined by -50 degrees, a method in which a layer containing these compounds is formed on a substrate such as a transparent film and oriented is generally used. As the transparent film, a resin film having no optical anisotropy and an optical axis substantially in the normal direction of the film, or a film having an in-plane retardation of 200 nm or less can be used. Examples of such a film include solvent cast films of cellulose resin, polycarbonate, polysulfone, polyether sulfone and acrylic resin. Above all, a triacetyl cellulose film, which is relatively inexpensive and has small optical anisotropy and is uniform, is preferably used. In addition, an alignment treatment layer, an adhesion-imparting layer, or the like for obtaining a desired orientation is formed on the surface of these films as needed. The method for forming a layer containing a compound having negative refractive index anisotropy on a transparent film substrate is not particularly limited, and a normal method such as direct gravure coater, reverse gravure coater, die coater, comma coater is used. However, a method using a precision coater lip coater that does not use a backup roll is preferable from the viewpoint of uniform layer thickness.

When a polymer compound is used, it is disclosed in JP-A-6-2.
As described in Japanese Patent No. 14116, a method of obliquely cutting out from a bulk polymer configured to exhibit a negative refractive index anisotropy so that an optical axis faces a predetermined direction with respect to a film surface, etc. Can be applied. Examples of bulky polymers configured to exhibit negative refractive index anisotropy include polymers having negative refractive index anisotropy, such as polystyrene and polymethylmethacrylate, which have a large refractive index in the side chain direction of the polymer. Is uniaxially oriented, or a polymer having a positive refractive index anisotropy with a large refractive index in the polymer main chain direction, such as polycarbonate, polysulfone, or polyethylene, is compressed to a plane direction perpendicular to the compression direction. For example, biaxially oriented materials can be used. In addition to this, a method of rolling a polymer film having positive refractive index anisotropy between a pair of heat rolls having different peripheral speeds while applying shear stress to the front and back surfaces of the film, such as mechanical stress on the polymer film. The method of adding is also applicable.

Further, even if it is difficult to orient the compound with negative refractive index anisotropy so as to incline the optical axis with respect to the normal direction of the film by 5 to 50 degrees, As long as it can be oriented so that it is almost normal to the film surface, it may be combined with one or two optically isotropic wedge-shaped sheets as shown in FIG. By applying the method of tilting, it has the same optical characteristics as the retardation film that changes asymmetrically with respect to the normal direction of the sheet when the retardation is measured by tilting with the slow axis as the tilt axis. It can also be done. In FIG. 3, 11 is an optically isotropic wedge-shaped sheet, 12 is an adhesive, and 13 is a retardation film having an optical axis in the normal direction of the film. The optically isotropic wedge-shaped sheet can be obtained by molding a resin in which birefringence is difficult to develop, such as a methacrylic resin or a low birefringence polycarbonate resin, by an injection molding method or the like.

In the present invention, the orientation in which the optical axis is tilted means that in the layer containing the compound having the above-mentioned negative refractive index anisotropy, all the compounds exhibiting optical characteristics are oriented with substantially the same tilt angle. Not only the state in which the compound is oriented, but also the orientation in which the orientation angle of the compound changes continuously or discontinuously with respect to the thickness direction. In this case, the optical axis cannot be defined as the entire layer containing the compound having negative refractive index anisotropy, but as the average tilt angle,
When the retardation is measured while tilting with the slow axis as the tilt axis, the angle obtained from the angle at which the retardation value takes the extreme value is regarded as the optical axis.

The polarizing film used in the present invention is not particularly limited. For example, 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 laminated sheet of the present invention comprises the above-mentioned light control plate,
A retardation film containing at least one compound having negative refractive index anisotropy, which exhibits an asymmetric change with respect to the normal direction of the film when the retardation is measured by inclining the slow axis as an inclination axis. It can be obtained by laminating a polarizing film and a polarizing film. The order of lamination is appropriately determined depending on 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 Examples of such structures are: 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.

The laminating method for forming the laminated sheet is not particularly limited. For example, a light control plate, at least one compound having negative refractive index anisotropy, and a tilted axis with the slow axis as the tilt axis are tilted. A method in which a retardation film and a polarizing film, each of which exhibits an asymmetrical change with respect to the normal direction of the film when the retardation is measured, are individually prepared and laminated using an adhesive or an adhesive, a light control plate When a polarizing film is used as a substrate when manufacturing the, and a laminated structure of a light control plate / polarizing film is directly used,
A method of laminating with a retardation film using a pressure-sensitive adhesive or an adhesive, using a polarizing film as a transparent resin substrate when manufacturing a retardation film, and directly using a laminated structure of polarizing film / retardation film A method of laminating with a light control plate using an agent or an adhesive can be used.

When the laminated sheet of the present invention is arranged and used on the surface of a liquid crystal display device, an additional function can be given to the surface of the laminated sheet. 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, fine unevenness may be formed on the surface to form an anti-glare layer that diffusely reflects external light, or an antireflection layer formed of a multilayer film of dielectric thin films. Furthermore, 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.

[0031]

By applying the laminated sheet of the present invention,
The viewing angle characteristics of the AM-TN-LCD can be improved more than ever, and in particular, the excellent effect of improving the gradation reversal in the specific direction, which is difficult to improve only by the retardation film, is exhibited.

[0032]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

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, 2,4,4 30 parts of 6-tribromophenyl acrylate (refractive index 1.576), 30 parts of 2-hydroxy-3-phenoxypropyl acrylate (refractive index 1.52)
6) and 2-hydroxy-2- as a photopolymerization initiator
Methyl propiophenone 1.5 parts, polymethyl methacrylate fine particles as a filler (MP-300, Soken Chemical Co., Ltd.)
Manufacture: 0.01 parts of an average particle size of 0.1 μm) was added and mixed to prepare a photopolymerizable composition.

This composition was applied to a polyethylene terephthalate film having a thickness of 188 μm, and the composition shown in FIGS.
After irradiating the ultraviolet ray having a wavelength of 350 nm or less with an irradiation angle of 30 degrees by the apparatus shown in FIG. In the figure, 1 is an 80 W / cm rod-shaped high-pressure mercury lamp, 2 is a light shield plate, 3 is a conveyor, 4 is a 188 μm polyethylene terephthalate film coated with a resin composition for a light control plate, and 5 is an ultraviolet irradiation angle in this example. Shows. The thickness of this light control plate is 165 μm, the maximum haze value is 85%, and the scattering angle range defined by a haze value of 30% or more is 1
It was in the range of 0 to 70 degrees.

On the other hand, Advanced Materials, 2 (1990) No.
In accordance with the method described in 1, p.40, oxidative coupling of o-dimethoxybenzene with iron trichloride / sulfuric acid system to obtain hexamethoxytriphenylene, followed by demethylation with boron bromide. , Hexahydroxytriphenylene was obtained. Hexa (4-heptyloxybenzoyloxy) triphenylene was synthesized by reacting 4-heptyloxybenzoic acid with thionyl chloride to form an acid chloride, and esterifying this with hexahydroxytriphenylene.

A triacetyl cellulose film (Fuji TAC SH-80, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm was formed by oblique vapor deposition of SiO at about 50 degrees to 400.
A 10% solution of hexa (4-heptyloxybenzoyloxy) triphenylene in methyl ethyl ketone was coated with a spin coater to a dry thickness of about 1 μm. A compound having a negative refractive index anisotropy was obtained by heating this film to 180 ° C., rapidly cooling it, and orienting it, and then overcoating it with a 2% aqueous solution of polyvinyl alcohol (Kuraray Poval 117H, manufactured by Kuraray Co., Ltd.). A retardation film having asymmetrical changes with respect to the normal direction of the film was obtained when the retardation was measured by inclining with the slow axis as the tilt axis. The change in retardation measured by tilting the slow axis of this film as the tilt axis was measured by ADR-100N manufactured by Oak Manufacturing Co., Ltd.
Was measured using. The measurement results are shown in FIG.

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 applied to the above-mentioned light control plate via an adhesive. Laminated, iodine-based polarizing film (Sumikaran SK-1842AP7, manufactured by Sumitomo Chemical Co., Ltd.) was laminated via an adhesive, and the above retardation film was further laminated via the adhesive on the polarizing film. In addition, a laminated sheet having three functions according to the present invention (constitution: antireflection layer / acrylic sheet / light control plate / polarizing film /
A retardation film) was obtained. At this time, the polarizing film was laminated so that the absorption axis of the polarizing film and the slow axis of the retardation film formed an angle of 90 degrees.

The above-prepared laminated sheet was applied to AM-TN.
-On the upper surface of the LCD (6E-A3, manufactured by Sharp Corporation), the absorption axis of the polarizing film is 45 degrees when viewed from above, the slow axis in the film plane of the retardation film is 135 degrees, and the film plane of the optical axis. It was attached so that the projection axis thereof was 225 degrees. On the lower surface, the absorption axis of the polarizing film is 45 degrees when viewed from below, and the retardation film made above between the polarizing film and the LCD is used. It was attached so that the projection axis thereof was 225 degrees. Structure: laminated sheet (antireflection layer / acrylic sheet / light control plate / polarizing film / retardation film) / LCD / retardation film / polarizing film

On this AM-TN-LCD, white display, black display and gray 8 gradation display were performed by a VG365N video pattern generator manufactured by MT Co., Ltd., and the contrast ratio at the time of white / black display and the 8th floor were displayed. The gradation reversal at the time of tonal display was measured by LCD-7000 manufactured by Otsuka Electronics Co., Ltd. in the range of 60 degrees in the vertical and horizontal directions. Table 1 shows the angles at which the contrast becomes 5 in the vertical and horizontal directions and the angles at which the gradation inversion occurs. This LCD showed excellent viewing angle characteristics in the vertical and horizontal directions, especially in the vertical direction.

Comparative Example 1 In the AM-TN-LCD manufactured in Example 1, an LCD similar to that in Example 1 was manufactured except that the light control plate was not used. The viewing angle characteristics of this AM-TN-LCD were measured in the same manner as in Example 1. Table 1 shows the angles at which the contrast becomes 5 in the vertical and horizontal directions and the angles at which the gradation inversion occurs.
This LCD had narrower viewing angle characteristics than the present invention in the downward direction.

[0041]

[Table 1]

[Brief description of drawings]

FIG. 1 is a side view of an example of an ultraviolet irradiation device for producing a light control plate used in the present invention.

FIG. 2 is a perspective view of the ultraviolet irradiation device.

FIG. 3 is a diagram showing an example of a retardation film in which two wedge-shaped sheets used in the laminated sheet of the present invention are combined.

FIG. 4 is a diagram showing changes in retardation of the retardation film of Example 1.

[Explanation of reference numerals] 1 bar-shaped ultraviolet lamp 2 light-shielding plate 3 conveyor 4 188 μm-thick polyethylene terephthalate film 5 coated with resin composition for light control plate 5 irradiation angle 11 optically isotropic wedge-shaped sheet 12 adhesive 13 Retardation film whose optical axis is in the film normal direction

Continuation of the front page (56) Reference JP-A-7-64069 (JP, A) JP-A-6-331826 (JP, A) JP-A-4-311903 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) G02F 1/13363 G02F 1/1335 G02B 5/02 G02B 5/30

Claims (14)

(57) [Claims] 1. Between domains obtained by irradiating with ultraviolet rays after forming a composition containing two or more kinds of photopolymerizable monomers or oligomers having different refractive indexes into a film shape.
At least one light control plate of a refractive index modulation type having a gap of 1 to 20 μm , including at least one compound having a negative refractive index anisotropy, and measuring a retardation by inclining the slow axis as an inclination axis At least one retardation film that changes asymmetrically with respect to the normal direction of the film ,
A laminated sheet comprising a laminated polarizing film and a polarizing film. 2. A composition containing two or more kinds of photopolymerizable monomers or oligomers having different refractive indexes from each other and a compound having a different refractive index and having no photopolymerizability from each other is formed into a film and then exposed to ultraviolet rays. Domain spacing obtained by irradiation
Of at least one light control plate having a refractive index modulation of 1 to 20 μm, and containing at least one compound having negative refractive index anisotropy, and measuring the retardation by tilting with the slow axis as the tilt axis. A laminated sheet characterized by laminating at least one retardation film , which has an asymmetric change with respect to the normal direction of the film , and a polarizing film. 3. The light control plates have refractive indices of at least one another.
Light rays from a specific angle range obtained by irradiating with ultraviolet rays after forming a composition containing at least two kinds of photopolymerizable monomers or oligomers different from 0.01 into a film shape.
It has a light-scattering power with a haze value of 30% or more for incident light.
Light scattering ability for light incident from other angle range
The laminated sheet according to claim 1 or 2, wherein the laminated sheet does not have . 4. The maximum ray incident angle range having ray scattering ability.
The laminated sheet according to claim 3 , which has a haze value of 30 to 85% . 5. The letter day is tilted with the slow axis as the tilt axis.
When measuring the
The optical axis of a retardation film that changes symmetrically is a film
At least 5 to 50 degrees with respect to the normal direction of
Includes a compound having one type of oriented negative refractive index anisotropy
Laminated sheet according to claim 1 or claim 2 wherein, characterized in that out. Retardation film asymmetrical change when 6. were inclined to the slow axis as an inclined axis to measure the retardation with respect to the normal direction of the film, the optical axis with respect to the normal direction of the film 3. The laminated sheet according to claim 1 or 2, comprising at least one type of compound having negative refractive index anisotropy oriented in a thickness direction . Retardation film asymmetrical change when 7. was inclined to the slow axis as an inclined axis to measure the retardation with respect to the normal direction of the film, the optical axis film
A film containing at least one compound having a negative refractive index anisotropy oriented substantially perpendicular to the plane.
Combined with one or two wedge-shaped sheets that are optically isotropic
The laminated sheet according to claim 1 or 2, which is a combination thereof . 8. A compound having negative refractive index anisotropy is organically modified.
Claim 5, claim 6 or claim 6 which is a compound
The laminated sheet according to claim 7 . 9. An organic compound having a negative refractive index anisotropy is
Claims characterized by being a discotic compound exhibiting liquid crystallinity
Item 8. A laminated sheet according to item 8 . 10. An organic compound having negative refractive index anisotropy
It showed no liquid crystallinity, negative refractive index by electric or magnetic fields
The laminated sheet according to claim 8 , which is an organic compound oriented so as to exhibit anisotropy . 11. A compound having a negative refractive index anisotropy is inorganic.
It is a compound , Claim 5, Claim 6 or
Is a laminated sheet according to claim 7 . 12. An inorganic compound having negative refractive index anisotropy
Is a swellable inorganic layered compound, The laminated sheet according to claim 11, wherein 13. The swellable inorganic layered compound has an average particle size of 1
The laminated sheet according to claim 12, which is a synthetic hectorite having a size of not more than μm . 14. The laminated sheet according to claim 1 or 2.
Twisted nematic liquid crystal display using at least one panel
Equipment .