JP2006163003A - Optical compensating element and its manufacturing method, liquid crystal display, and liquid crystal projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical compensating element having little long term deterioration by preventing light leakage in a wide field angle, and optically compensating a liquid crystal layer of a black display state in higher precision, and to provide its manufacturing method, and a liquid crystal display and a liquid crystal projector having high image quality in high field angle and high contrast by using the optical compensating element. <P>SOLUTION: The optical compensating element and its manufacturing method comprise a first optical anisotropic layer formed of an inorganic material, and a second optical anisotropic layer formed of a polymerization liquid crystal compound and having a means for holding a deoxidation atmosphere. The liquid crystal display comprises a liquid crystal element having a liquid crystal molecule sealed between a pair of electrodes, the optical compensating element arranged on both the faces or one face of the liquid crystal element, and a polarizing element arranged oppositely on the liquid crystal element and the optical compensating element. The liquid crystal projector displays images by image-forming optically modulated light by the liquid crystal display on a screen by a projection optical system by irradiating illumination light from a light source on the liquid crystal display. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical compensation element with little deterioration in optical characteristics and a method for manufacturing the same, a liquid crystal display device, and a liquid crystal projector for long-term use.

In recent years, the use of liquid crystal display devices has been rapidly advanced, and is used in mobile phones, personal computer monitors, televisions, liquid crystal projectors, and the like.
In general, a liquid crystal display device is in a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, an IPS (In-Plane Switching) mode, an OCB (Optically Compensatory Bend) mode, an ECB (Electrically Bending mode), or the like. It is a display device that expresses characters and images by operating a liquid crystal and electrically controlling light passing through the liquid crystal to display a difference between light and dark on a screen.
As such a liquid crystal display device, a TFT (Thin Film Transistor) -LCD is generally known, and a TN mode is mainstream as a liquid crystal operation mode of the TFT-LCD. On the other hand, as the application development of liquid crystal display devices progresses in recent years, the demand for higher contrast has increased, and research on VA mode liquid crystal display devices has been actively conducted.
In a TN mode liquid crystal display device, nematic liquid crystal twisted by 90 ° is enclosed between two glass substrates, and a pair of polarizing plates are arranged in crossed Nicols outside the two glasses. When no voltage is applied, the linearly polarized light that has passed through the polarizer on the polarizer side is twisted by 90 ° in the liquid crystal layer and passes through the polarizer on the analyzer side, resulting in white display. In addition, when the voltage is sufficiently applied, the alignment direction of the liquid crystal changes substantially perpendicular to the liquid crystal panel, and the linearly polarized light passing through the polarizer on the polarizer side passes through the liquid crystal layer without changing the polarization state. As a result, the light reaches the polarizing plate on the analyzer side and black is displayed.
On the other hand, in the VA mode liquid crystal display device, nematic liquid crystal is sealed between two glass substrates so as to be vertically aligned or vertically inclined, and a pair of polarizing plates is crossed Nicols on the outside of the two glasses. Is arranged in. When no voltage is applied, the linearly polarized light that has passed through the polarizer on the polarizer side passes through the liquid crystal layer with almost no change in the plane of polarization in the liquid crystal layer, reaches the polarizer on the analyzer side, and displays black. Become. In addition, when the voltage is sufficiently applied, the alignment direction of the liquid crystal changes parallel to the liquid crystal panel and twisted by 90 °, and the linearly polarized light passing through the polarizer on the polarizer side is polarized by the liquid crystal layer. The surface is twisted by 90 ° and passes through the polarizing plate on the analyzer side, resulting in a white display.
In a liquid crystal display device operating in these display modes, when the display screen is viewed from an oblique direction, due to light leakage, a contrast inversion or a gradation inversion phenomenon in which the brightness is reversed in gradation display occurs. There's a problem.

In order to improve such problems, conventionally, the retardation value of light passing through the liquid crystal layer in the black display state and the retardation value of the optically anisotropic layer are combined to form the liquid crystal layer in the black display state. An optical compensation film has been proposed that optically compensates three-dimensionally, eliminates light leakage from any direction, and improves the problem of viewing angle dependency.
For example, an optical compensation sheet comprising a support such as a triacetyl cellulose (TAC) film and an optically anisotropic layer provided thereon by the applicant of the present application, wherein the optically anisotropic layer is a discotic structural unit. The disc surface of the discotic structural unit is inclined with respect to the support surface, and the disc surface of the discotic structural unit is formed by the support surface. There has been proposed an optical compensation film having a hybrid orientation in which the angle changes in the thickness direction of the optically anisotropic layer, and the support has the characteristics of an optically nearly uniaxial negative refractive index ellipsoid ( Patent Document 1).
According to this optical compensation film, since the discotic structural unit of the optically anisotropic layer is arranged so as to be mirror-symmetrical with the liquid crystal layer in the black display state, the support and the discotic structural unit As the optical characteristics of the entire laminate, the liquid crystal layer in the black display state is optically compensated, and light leakage can be prevented in a wide viewing angle.

However, in this case, by using the optical compensation film, the problem of the viewing angle dependency of the liquid crystal display device has been improved and the viewing angle has been successfully expanded. The demand for liquid crystal monitors, liquid crystal projectors, and the like has increased, and there has been a demand for the large-screen liquid crystal monitors, liquid crystal projectors, and the like that have little deterioration in display quality such as fading and color shift even when used for a long period of time. In addition, since the liquid crystal projector integrates light incident on the liquid crystal cell at various angles and is projected on the screen in an enlarged manner, higher contrast is required, and the optical compensation film still has room for improvement. .
Further, conventionally, an optical film having a hybrid-aligned liquid crystal layer is arranged between two polarizing plates arranged so as to sandwich a liquid crystal cell, and the optical film is made of a plastic film having extremely low birefringence. There is known a method for improving the contrast ratio of a liquid crystal projector in which a hybrid-aligned liquid crystal layer is disposed on a base film (see Patent Document 2). However, even in this case, in the optical compensation film, the optically anisotropic layer is made of an organic material such as a polymerizable liquid crystal compound, and an alignment film coating liquid made of an organic polymer is applied onto the optical compensation film. Thereafter, the optically anisotropic layer coating solution is applied by a coating method or the like. In such a coating process, air is filled in the layer of the optical compensation film, so about 21% of oxygen, water, nitrogen oxides and sulfur oxides (for example, sulfite compounds) contained in the air. Molecules such as various solvent gases generated in the coating step adhere (adsorb) to the alignment film of the optically anisotropic layer. For this reason, the obtained optical compensation element gradually deteriorates in quality as the optically anisotropic layer and the alignment film change over time due to adverse effects such as the adhesion of these attached molecules to the organic material and causing an oxidation reaction. The display quality of the optical compensation element is deteriorated.
In particular, when used in a liquid crystal projector, the oxidation reaction is accelerated by light irradiation, and among the red, green, and blue channels, the blue channel is greatly deteriorated, which not only lowers the contrast but also causes color balance. There is a problem. There is a demand for an optical compensation element that suppresses an oxidation reaction of an organic material that causes such deterioration and has durability (light resistance) without deterioration over time. As these improvement methods, a method is known in which a protective layer is provided on an organic material layer by means of vapor deposition of an inorganic material or application of an organic material to suppress an oxidation reaction (see Patent Documents 3 to 5). However, in this case, the gas barrier properties in the light passing direction and the normal direction of each layer can be improved, but the effect of the contamination of the optical compensation element from the end face of the optical compensation element is lacking and the effect of the optical compensation element is reduced. It was insufficient to prevent aging of the organic material part.

JP-A-8-50206 Republished patent WO01 / 090808 JP-A-6-289227 JP-A-5-27114 JP 2001-91747 A

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention optically compensates a liquid crystal layer in a black display state with higher accuracy, prevents light leakage at a wide viewing angle, and has a little deterioration over time, and a method of manufacturing the optical compensation element An object of the present invention is to provide a liquid crystal display device and a liquid crystal projector that have a long viewing angle, high contrast, and high image quality by using the optical compensation element.

Means for solving the problems are as follows. That is,
<1> An optical compensation element having sealing means for sealing the optical compensation element.
<2> The optical compensation element according to <1>, wherein the sealing unit includes a sandwiching member that sandwiches the optical compensation element and a sealing unit that seals the peripheral side surface.
<3> The optical compensation element according to any one of <1> to 2, wherein the sandwiching member that sandwiches the optical compensation element is at least one of an inorganic vapor deposition film and glass.
<4> The optical compensation element according to any one of <1> to <3>, wherein the optical compensation element uses a twisted nematic liquid crystal element.
<5> The optical compensation element according to any one of <1> to <4>, wherein the optical compensation element is a viewing angle widening film.
<6> The optical compensation element comprises a first optical anisotropic layer formed of an inorganic material on a support and a second optical anisotropic layer formed of a polymerizable liquid crystal compound,
The first optically anisotropic layer is a periodic structure laminate in which a plurality of layers having different refractive indexes are laminated in a regular order and a repeating unit is repeated, and the negative refractive index anisotropic as a whole. Have
The second optically anisotropic layer is formed of a polymerizable liquid crystal compound including a liquid crystal structure, and has a hybrid orientation in which an orientation angle of the liquid crystal structure changes with respect to a thickness direction of the second optically anisotropic layer. The optical compensation element according to any one of <1> to <5>.
<7> The optical compensation element according to <6>, wherein the second optically anisotropic layer includes two layers having different orientation directions.
<8> A liquid crystal element having at least a pair of electrodes and liquid crystal molecules sealed between the pair of electrodes, an optical compensation element disposed on either one or both sides of the liquid crystal element, the liquid crystal element, and the optical compensation A liquid crystal display device comprising: a polarizing element disposed opposite to the element, wherein the optical compensation element is the optical compensation element according to any one of <1> to <7>.
<9> A light source, a liquid crystal display device irradiated with illumination light from the light source, and a projection optical system that forms an image of light modulated by the liquid crystal display device on a screen, the liquid crystal display device A liquid crystal projector according to <8>, wherein the liquid crystal display device is the liquid crystal display device.

The optical compensation element of the present invention comprises a first optical anisotropic layer formed of an inorganic material and a second optical anisotropic layer formed of a polymerizable liquid crystal compound on the surface of a support. And having a sealing means for sealing the optical compensation element, the liquid crystal layer in the black display state is optically compensated with higher accuracy to prevent light leakage in a wide viewing angle and to improve the display quality for a long period of time. Deterioration can be suppressed.
The method for producing an optical compensation element of the present invention includes an optical compensation element body forming step of forming an optical compensation element body by laminating an optically anisotropic layer on a support, and deoxidizing the optical compensation element body. In addition, a liquid crystal layer in a black display state can be obtained with higher accuracy by laminating each process and then sealing the optical compensation element in a deoxygenated atmosphere. It is possible to manufacture an optical compensation element that compensates optically, prevents light leakage over a wide viewing angle, and has very little deterioration in display quality.
Further, the liquid crystal display device of the present invention includes at least a pair of electrodes, a liquid crystal element having liquid crystal molecules injected between the pair of electrodes, and an optical compensation element disposed on either one or both sides of the liquid crystal element. Since the liquid crystal element and the polarizing element disposed opposite to the optical compensation element, and the optical compensation element is the optical compensation element of the present invention, a high viewing angle and high contrast can be obtained for a long period of time.
The liquid crystal projector of the present invention includes a light source, a liquid crystal display device irradiated with illumination light from the light source, and a projection optical system that forms an image of light modulated by the liquid crystal display device on a screen. Since the liquid crystal display device is the liquid crystal display device of the present invention, a high viewing angle, high contrast, and long life can be achieved.

  According to the present invention, an optical compensation element that solves the above-described problems, optically compensates a liquid crystal layer in a black display state with higher accuracy, and prevents light leakage in a wide viewing angle, and manufacture of the optical compensation element By using the method and the optical compensation element, it is possible to provide a liquid crystal display device and a liquid crystal projector that can maintain a high viewing angle, high contrast, and high image quality over a long period of time.

(Optical compensation element)
The optical compensation element of the present invention has a first optical anisotropic layer formed of an inorganic material and a second optical anisotropic layer formed of a polymerizable liquid crystal compound on the surface of the support. And a pair of plate members that are sandwiching members for sandwiching the optical compensation element, and a sealing member that seals the peripheral side surface. The optical compensation element has other layers as required.

-Support-
The support is not particularly limited as long as it is excellent in transparency and exhibits a light transmittance of 80% or more and gives uniform optical characteristics, and can be appropriately selected according to the purpose. Examples thereof include glass, blue plate glass, quartz glass, alkali-free glass, sapphire glass, and an organic polymer film.
The organic polymer film is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polyarylate, polyester, polycarbonate, polyolefin, polyether, polysulfine, polysulfone, One type or a combination of two or more types selected from a polymer group such as polyether sulfone type and cellulose ester type may be mentioned.
Specific examples of the organic polymer film include a polycarbonate copolymer, a polyester copolymer, a polyester carbonate copolymer, and a polyarylate copolymer, and a polycarbonate copolymer is more preferable.
The polycarbonate copolymer is preferably a polycarbonate copolymer having a fluorene skeleton, and is obtained by reacting a bisphenol with a carbonate ester-forming compound such as phosgene or diphenyl carbonate from the viewpoint of transparency, heat resistance, and productivity. Polycarbonate copolymers are particularly preferred.
As content of the fluorene skeleton which the said polycarbonate copolymer has, 1-99 mol% is preferable. As the polycarbonate copolymer, it is also possible to use repeating units described in WO 00/26705 pamphlet.
Specific examples include films made of plastics such as triacetylcellulose, polyvinyl alcohol, polyimide, polyarylate, polyester, polycarbonate, polysulfone, polyethersulfone, and epoxy resin.
As the support, glass or triacetyl cellulose film made of the various inorganic materials described above can be suitably used from the viewpoint of surface smoothness and the like.
The thickness of the support is not particularly limited and can be appropriately selected according to the purpose, and is preferably 0.1 μm or more, and the upper limit of the thickness is from the viewpoint of built-in handling properties and mechanical strength. 0.3 mm-3 mm are preferable and 0.5 mm-1.5 mm are more preferable.

-First optical anisotropic layer-
The structure of the first optically anisotropic layer is not particularly limited as long as it is formed of an inorganic material and has optical anisotropy as a whole layer, and can be appropriately selected according to the purpose. For example, a periodic structure in which a plurality of layers having different refractive indexes are laminated in a regular order with a normal direction of the support as a lamination direction, and a repeating unit is repeated (having a repeating structure) A structure in which the optical thickness of the repeating unit, that is, the thickness in the stacking direction of the repeating structure in the periodic structure stacked body (hereinafter referred to as “periodic structure pitch”) is shorter than the wavelength of light in the visible light region. Are preferable.
In addition, the thickness in the stacking direction of one repeating structure in the periodic structure stacked body and the thickness in the stacking direction of the other repeating structure are not necessarily the same. It is also possible to make it different depending on the nature of the light to be transmitted.
The number of layers constituting the one repeating structure is not particularly limited as long as it is a plurality of types of layers having different refractive indexes, and can be appropriately selected according to the purpose. Preferred examples include those composed of two layers of the inorganic material.
The thickness of each layer constituting the periodic structure laminate is not particularly limited as long as it is smaller than the wavelength of light in the visible light region, and can be appropriately selected according to the purpose. When the wavelength is λ, λ / 100 to λ / 5 is preferable, λ / 50 to λ / 5 is more preferable, and λ / 30 to λ / 10 is particularly preferable.
As the thickness of each layer constituting the periodic structure laminate, since it is necessary to avoid the occurrence of optical interference between the laminated layers, the thickness of each layer is preferably thin, but the required total thickness is obtained. However, in determining the thickness of each layer, the desired optical characteristics of the first optical anisotropic layer, the problem of coloring due to mutual interference of the layers, and the like are taken into consideration when determining the thickness of each layer. It is preferable that the optimum value of the thickness of each layer is determined from the material, refractive index, thickness ratio, total thickness, and the like.

The periodic structure pitch is not particularly limited as long as it is shorter than the wavelength of light in the visible light region, and can be appropriately selected from the visible light region according to the purpose. The light region refers to a wavelength region of 400 to 700 nm unless otherwise specified. Therefore, it is preferable that the periodic structure pitch is appropriately selected within a range of 400 to 700 nm.
As the retardation of the first optically anisotropic layer, the retardation Rth represented by the following formula (1) is preferably 20 to 300 nm, more preferably 20 to 200 nm.
Rth = {(n _x + n _y ) / 2−n _z } × d (1)
However, in said Formula (1), _nx , _ny, and _nz are X, Y orthogonal to each other in the 1st optically anisotropic layer when the normal line direction of the said support body is made into a Z-axis. Represents the refractive index in the Z-axis direction. D represents the thickness of the optically anisotropic layer.
There is no restriction | limiting in particular as the number of the repeating structures in the said periodic structure laminated body, According to the objective, it can select suitably.
The thickness of the first optically anisotropic layer is preferably one that satisfies the retardation Rth, specifically 50 to 2000 μm, more preferably 100 to 1500 μm.

The material of the periodic structure laminate constituting the first optically anisotropic layer is not particularly limited and may be appropriately selected depending on the intended purpose. Since the retardation value due to refraction is determined by the product of the thickness d of the optically anisotropic layer and the refractive index difference Δn of each layer constituting the repetitive structure, it is appropriately selected according to the desired refractive index difference Δn. Specifically, it is preferable that the material having a high refractive index is appropriately selected from TiO ₂ , ZrO _{2 and the} like, and the material having a low refractive index is appropriately selected from SiO ₂ , MgF _{2 and the} like.
Specifically, the material of the periodic structure laminate is preferably selected from a combination of materials in which the refractive index difference Δn between the maximum value and the minimum value of the refractive index in the visible light region is 0.5 or more. In addition, a combination of a plurality of materials appropriately selected from oxide layers is more preferable, and a SiO ₂ layer (refractive index n = 1.4870 to 1.5442) and a TiO ₂ layer (refractive index n = 2.583 to 2.741). ) Is particularly preferred.
If the refractive index difference Δn is less than 0.5, the thickness d of the optically anisotropic layer is adjusted, and the retardation value in the first optically anisotropic layer becomes a desired value. In addition, the number of steps for laminating repeating units increases, which is not preferable in consideration of manufacturability and productivity.
Such a first optically anisotropic layer is equivalent to a medium having a uniform refractive index in the stacking direction of each layer, that is, the normal direction of the support, and the entire layer has a structural compound. Due to the occurrence of anisotropy called refraction, it has the optical characteristics of a negative refractive index ellipsoid that is not uniaxially inclined. The first optically anisotropic layer has high smoothness, and the retardation and the like can be selected by appropriately selecting the material, thickness, number of layers, period of the periodic structure pitch, and the like of the periodic structure laminate. Can be obtained easily and with high accuracy.

In addition, the first optically anisotropic layer can be given a function as an antireflection layer by appropriately selecting the thickness ratio and thickness of each layer.
In addition, there is no restriction | limiting in particular as measurement of the said retardation Rth, According to the objective, it can select suitably, For example, it can measure using an ellipsometer (M-150, JASCO Corporation make). it can.

-Second optical anisotropic layer-
The second optically anisotropic layer includes at least a polymerizable liquid crystal compound, and further includes other configurations appropriately selected as necessary.

The polymerizable liquid crystal compound is not particularly limited and may be appropriately selected depending on the purpose. It is preferable to use a polymerizable liquid crystal compound including a liquid crystal structure in which the alignment state can be fixed. A polymerizable liquid crystal compound having a liquid crystal structure such as a liquid crystal structure or a banana-like liquid crystal structure is more preferable, and a polymerizable liquid crystal compound having a discotic liquid crystal structure is particularly preferable.
Further, the polymerizable liquid crystal compound can contain other components appropriately selected as necessary.

In the present invention, the natural axis of the molecules constituting the liquid crystal is set in the long axis direction if it is a rod-like molecule such as a rod, or the normal direction of the plate if it is a plate-like molecule. In this case, it is said that the liquid crystal structure is in an aligned state that the average directions of the eigen axes of the liquid crystal structure included in the microscopic area of interest are substantially aligned. Further, according to the present invention, when in this alignment state, the average direction of the natural axis of the liquid crystal structure in the microscopic area of interest and the stacking direction of the optical compensation element (at the interface between the second optical anisotropic layer and the support) The angle formed with the (normal direction) is referred to as the orientation angle, and the component obtained by projecting the average direction of the natural axis onto the interface is referred to as the orientation direction.
As the alignment state, it is preferable that the alignment angle of the liquid crystal structure is inclined, that is, the alignment angle is not parallel or perpendicular to the thickness direction of the second optical anisotropic layer. More preferred are those having a hybrid orientation in which the orientation angle continuously changes in the thickness direction between the upper surface and the lower surface of the second optically anisotropic layer.
The orientation angle in the hybrid orientation is preferably adjusted so as to continuously change in the range of 20 ° ± 20 ° to 65 ° ± 25 ° from the orientation film side to the air interface side.

As the alignment state determined by the alignment angle and the alignment direction of the polymerizable liquid crystal compound, it is preferable that the alignment angle and the alignment method are adjusted so that the liquid crystal layer in a black display state and a mirror surface target.
Here, in the second optically anisotropic layer, the alignment angle in the vicinity of the alignment film side of the liquid crystal structure, the alignment angle on the air interface side, and the average alignment angle are determined using an ellipsometer (M-150, manufactured by JASCO Corporation). ) Is used to measure retardation from multiple directions, a refractive index ellipsoid model is assumed from the measured retardation, and the estimated value calculated from the refractive index ellipsoid model.
In addition, as a method of calculating the orientation angle from the retardation, it is also possible to calculate by an approach described in Design Concepts of Discrete Negative Birefringence Compensation Films SID98 DIGEST. The measurement direction of the retardation in calculating the orientation angle is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the retardation in the normal direction of the optically anisotropic layer (Re0 ), Retardation in the −40 ° direction with respect to the normal direction (Re-40) and retardation in the + 40 ° direction (Re40).
The measurements of Re0, Re-40, and Re40 are values obtained by changing the observation angle in each of the measurement directions using the ellipsometer.

There is no restriction | limiting in particular as a polymeric liquid crystal compound containing the said rod-shaped liquid crystal structure, It can select suitably according to the objective, For example, the polymerizability which made it possible to fix the orientation state of the said rod-shaped liquid crystal structure using a polymer binder. Examples thereof include a liquid crystal compound and a polymerizable liquid crystal compound having a polymerizable group capable of fixing the alignment state of the liquid crystal structure by polymerization, and among these, the polymerizable liquid crystal compound having a polymerizable group is preferable.
The rod-like liquid crystal structure is not particularly limited and may be appropriately selected depending on the intended purpose. For example, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoates, cyclohexanecarboxylic acid phenyl esters Cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles.

Examples of the polymerizable liquid crystal compound having a rod-like liquid crystal structure include a polymer liquid crystal compound obtained by polymerizing a rod-like liquid crystal compound having a low-molecular polymerizable group represented by the following structural formula (1).
However, in the structural formula (1), Q ¹ and Q ² each represent a polymerizable group, and L ¹ , L ² , L ³ and L ⁴ each represent a single bond or a divalent linking group, At least one of L ² and L ³ represents —O—CO—O—. A ¹ and A ² each independently represent a spacer group having 2 to 20 carbon atoms. M represents a mesogenic group.

  The polymerizable liquid crystal compound containing the discotic liquid crystal structure is not particularly limited and can be appropriately selected depending on the purpose. For example, the orientation state of the discotic liquid crystal structure can be fixed using a polymer binder. Polymerizable liquid crystal compounds, polymerizable liquid crystal compounds having a polymerizable group capable of fixing the alignment state of the discotic liquid crystal structure by polymerization, and the like. Among them, the polymerizable liquid crystal compound having a polymerizable group is preferable. It is done.

Examples of the polymerizable liquid crystal compound having a polymerizable group include a structure in which a linking group is introduced between a discotic core and a polymerizable group. Specific examples of the polymerizable liquid crystal compound include compounds represented by the following structural formula (2) as described in JP-A-8-050206.
In the structural formula (2), D represents a discotic core, L represents a divalent linking group, and P represents a polymerizable group. Moreover, n is an integer of 4-12. Further, the combination of a plurality of divalent linking groups L and polymerizable groups P may be a combination of different divalent linking groups and polymerizable groups, but the same combination is preferred. As the disk-shaped core D, two or more kinds can be used in combination.
In the structural formula (2), specific examples of the disk-shaped core D include disk-shaped cores represented by the following structural formulas (D1) to (D15).







In the structural formula (2), the divalent linking group L is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an alkylene group, an alkenylene group, an arylene group, —CO—, —NH -, -O-, -S-, combinations thereof and the like are preferable, alkylene group, alkenylene group, arylene group, -CO-, -NH-, -O-, -S-, and a divalent group selected from these More preferred is a divalent linking group in which at least two of the above groups are combined, and an alkylene group, alkenylene group, arylene group, -CO-, -O-, or at least two divalent groups selected from these are combined. A divalent linking group is particularly preferred.
The number of carbon atoms of the alkylene group is preferably 1-12. The number of carbon atoms of the alkenylene group is preferably 2-12. The number of carbon atoms of the arylene group is preferably 6-10. The alkylene group, the alkenylene group, and the arylene group may have a substituent such as an alkyl group, a halogen atom, a cyano, an alkoxy group, or an acyloxy group.
Specific examples of the divalent linking group L include -AL-CO-O-AL-, -AL-CO-O-AL-O-, -AL-CO-O-AL-O-AL-,- AL-CO-O-AL-O-CO-, -CO-AR-O-AL-, -CO-AR-O-AL-O-, -CO-AR-O-AL-O-CO-,- CO-NH-AL-, -NH-AL-O-, -NH-AL-O-CO-, -O-AL-, -O-AL-O-, -O-AL-O-CO-,- O-AL-O-CO-NH-AL-, -O-AL-S-AL-, -O-CO-AL-AR-O-AL-O-CO-, -O-CO-AR-O- AL-CO-, -O-CO-AR-O-AL-O-CO-, -O-CO-AR-O-AL-O-AL-O-CO-, -O-CO-AR-O- AL-O-AL-O-AL-OC -, - S-AL -, - S-AL-O -, - S-AL-O-CO -, - S-AL-S-AL -, - such as S-AR-AL- the like.
However, in the specific example of the divalent linking group L, the left side is bonded to the discotic core D, and the right side is bonded to the polymerizable group P. AL represents an alkylene group or an alkenylene group, and AR represents an arylene group.

In the structural formula (2), the polymerizable group P is not particularly limited and may be appropriately selected depending on the kind of the polymerization reaction, and is preferably an unsaturated polymerizable group or an epoxy group, and is ethylenically unsaturated. A polymerizable group is more preferable. Specific examples of the polymerizable group P include polymerizable groups represented by the following structural formulas (P1) to (P18).






As for these polymerizable liquid crystal compounds, for example, JP-A-9-104656, JP-A-11-92220, JP-A 2000-34251, JP-A 2000-44507, JP-A 2000-44517. JP-A-2000-86589 can be exemplified.

  The other components contained in the polymerizable liquid crystal compound are not particularly limited and may be appropriately selected depending on the purpose. For example, a polymerization initiator that initiates a polymerization reaction of the polymerizable liquid crystal compound, the polymerizable property Examples thereof include a solvent for preparing a liquid crystal compound coating solution.

The polymerization initiator is not particularly limited and may be appropriately selected depending on the purpose.For example, a thermal polymerization initiator that initiates a thermal polymerization reaction, a photopolymerization initiator that initiates a photopolymerization reaction, and the like. Among these, the said photoinitiator is mentioned suitably.
Specific examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbons. A substituted aromatic acyloin compound (described in US Pat. No. 2,722,512), a polynuclear quinone compound (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of a triarylimidazole dimer and p-aminophenyl ketone ( U.S. Pat. No. 3,549,367), acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850), oxadiazole compounds (described in U.S. Pat. No. 4,221,970) Can be mentioned.
There is no restriction | limiting in particular as content in the said polymeric liquid crystal compound of the said photoinitiator, According to the objective, it can select suitably, 0.01-20 of solid content in the coating liquid of the said polymeric liquid crystal compound % By weight is preferable, and 0.5 to 5% by weight is more preferable.
There is no restriction | limiting in particular as a light irradiation means used for the said photopolymerization reaction, According to the objective, it can select suitably, For example, an ultraviolet-ray is mentioned suitably. The irradiation energy of the light irradiation unit, preferably ^{20m~50J / cm 2, 100~800mJ / cm} 2 is more preferable.
In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions.

There is no restriction | limiting in particular as said solvent, According to the objective, it can select suitably, An organic solvent is mentioned suitably. Specific examples of the organic solvent include N, N-dimethylformamide, N, N-dimethylacetamide, amides such as N-methylpyrrolidone, sulfoxides such as dimethyl sulfoxide, heterocyclic compounds such as pyridine, carbonization such as benzene and hexane. Alkyl halides such as hydrogen, chloroform and dichloromethane, esters such as methyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ketoesters such as methyl acetoacetate and ethyl acetoacetate, tetrahydrofuran, 1,2-dimethoxyethane, Preferred examples include ethers such as diethylene glycol diethyl ether and dipropylene glycol dimethyl ether, and cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve. Among these, amides, Ether, ketones more preferable. As the organic solvent, two or more of these may be used in combination.
There is no restriction | limiting in particular as a polymerization method of the said polymeric liquid crystal compound, According to the objective, it can select suitably, For example, the method of Unexamined-Japanese-Patent No. 8-27284 and Unexamined-Japanese-Patent No. 10-278123 is used. It is also possible.

There is no restriction | limiting in particular as another structure with which the said 2nd optically anisotropic layer is equipped, It can select suitably according to the objective, The alignment film for orientating the said liquid crystal structure contained in the said polymeric liquid crystal compound Are preferable. It is preferable that the polymerizable liquid crystal compound is laminated on the alignment film by coating or the like.
The alignment film is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an alignment film made of a rubbed organic compound (polymer), an alignment film having a microgroup, a Langmuir-Blodgett method (LB film) alignment film in which organic compounds such as ω-triconic acid, dioctadecyldimethylammonium chloride, methyl stearylate are accumulated, alignment film in which inorganic compounds are obliquely deposited, alignment by electric field, magnetic field or light irradiation Examples thereof include an alignment film having a function, and an alignment film made of the rubbed organic compound is preferable.

There is no restriction | limiting in particular as said rubbing process, According to the objective, it can select suitably, For example, the process which rubs the surface of the film | membrane which consists of said organic compound several times in a fixed direction with paper or cloth is mentioned.
The type of the organic compound is not particularly limited and can be determined according to the alignment state (particularly the alignment angle) of the liquid crystal structure. For example, the surface energy of the alignment film for aligning the liquid crystal structure horizontally. Examples thereof include polymers for alignment films that do not lower the thickness.
Specific examples of the alignment film polymer include modified polyvinyl alcohol (described in JP-A-2002-62427), acrylic acid-based polymer when the liquid crystal structure is aligned in a direction orthogonal to the rubbing treatment direction. Preferred examples include copolymers (described in JP-A No. 2002-98836) polyimide and polyamic acid (described in JP-A No. 2002-268068).
The alignment film preferably has a reactive group for the purpose of improving adhesion to the polymerizable liquid crystal compound and the support. There is no restriction | limiting in particular as said reactive group, According to the objective, it can select suitably, For example, what introduce | transduced the reactive group into the side chain of the repeating unit of the said polymer for alignment films, The said polymer for alignment films In which a substituent of a cyclic group is introduced.
As the alignment film that forms a chemical bond with the polymerizable liquid crystal compound and the support by the reactive group, an alignment film described in JP-A-9-152509 can also be used.
There is no restriction | limiting in particular as thickness of alignment film, According to the objective, it can select suitably, 0.01-5 micrometers is preferable and 0.02-2 micrometers is more preferable.

The method for producing the second optically anisotropic layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polymerizable liquid crystal compound containing the liquid crystal structure in the solvent, the polymerization initiation A method of forming a coating liquid containing an agent or the like by coating on the alignment film is preferable.
The method for applying the coating liquid onto the alignment film is not particularly limited, and examples thereof include known methods such as an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a die coating method, and a spin coating method.

-Other layers-
There is no restriction | limiting in particular as said other layer, According to the objective, it can select suitably, For example, an antireflection layer, an anti-glare layer, an antifouling layer, an antistatic layer etc. are mentioned.
The material and structure of the antireflection layer are not particularly limited as long as they reduce the reflectance and increase the transmittance, and can be appropriately selected according to the purpose. A known AR film (Anti Reflection) Coat Film).

―Sealing means―
The sealing means is not particularly limited as long as it can be sealed and satisfies the optical characteristics, and can be appropriately selected according to the purpose. For example, the peripheral side surface is sealed by holding the optical compensation element with a holding body. For example, a pack structure that wraps the whole in a sheet-like structure, a storage structure that is housed in a case-like container, and the like.
Specifically, a sandwich structure including a pair of plate members that sandwich the optical compensation element and a sealing member that seals the peripheral side surface is preferable.
As a function of the sealing means, after removing impurities such as molecules such as moisture, oxygen, and various solvent gases adhering to the optical compensation element, the optical compensation element is sealed, and a clean state free of impurities There is a work to hold. Furthermore, if the gas is replaced with an inert gas before sealing, the high-quality state can be maintained for a longer period of time, the oxidation reaction occurring inside the optical compensation element can be suppressed, and fading and contrast reduction can be suppressed. It works to increase the durability.

--Plate material--
The material of the plate material is not particularly limited as long as it has mechanical strength and sealing properties, is excellent in transparency, exhibits a light transmittance of 80% or more, and satisfies uniform optical characteristics. Can be selected as appropriate, and examples thereof include inorganic materials and organic materials. Moreover, when the above-mentioned support body and each layer have the stable weather resistance, you may serve as the function of a plate material.
As said inorganic material, glass, such as white plate glass, blue plate glass, quartz glass, sapphire glass, can be used conveniently, for example.
The organic material is not particularly limited and can be appropriately selected depending on the purpose. For example, triacetyl cellulose, polyvinyl alcohol, polyimide, polyarylate, polyester, polycarbonate, polysulfone, polyethersulfone, epoxy resin Examples include films made of such plastics.
The thickness of the plate material is not particularly limited and can be appropriately selected according to the purpose, and is preferably 0.1 μm or more, and the upper limit of the thickness is from the viewpoint of built-in handling properties and mechanical strength, 0.3 to 3 mm is more preferable, and 0.5 to 1.5 mm is particularly preferable.
The size of the plate material is not particularly limited as long as it covers the entire laminated optically anisotropic layer, and can be appropriately selected according to the purpose. Is preferably the same size as or larger than
The shape of the plate material is not particularly limited as long as it satisfies the optical characteristics, and can be appropriately selected according to the purpose, and is preferably a flat sheet that can be in close contact with the optical compensation element.

-Sealing member-
The material of the sealing member is not particularly limited as long as the sealing property is maintained, and can be appropriately selected according to the purpose. For example, the ultraviolet curable resin composition, the thermosetting resin composition, one-component or two-component Epoxy resin bonding agents, solvent-based adhesives based on synthetic rubber, modified silicone resin adhesives, silylated urethane resin adhesives, and the like, and ultraviolet curable or epoxy resin bonding agents are preferred.
The sealing position of the sealing member may be at least the side surface of the layer that wants to block contact with the outside air, but from the viewpoint of ease of formation or usage, the entire peripheral side surface of the optical compensation element sandwiched by the plate material Good.
The thickness of the sealing member is not particularly limited as long as it can be sealed, and can be appropriately selected according to the purpose, and is preferably 0.1 μm or more. From the viewpoint of sealing properties, 0.1 to 1.1 mm is preferable, and 0.1 to 0.7 mm is more preferable.
The ultraviolet compensation type or epoxy resin bonding agent is applied to the peripheral side surface of the optical compensation element sandwiched by the plate material and cured to seal the optical compensation element.
The sealing member seals the entire peripheral side surface of the optical compensation element, and prevents impurities such as molecules such as moisture, oxygen, and various solvent gases from entering from the outside.

(Manufacturing method of optical compensation element)
An optical compensation element manufacturing method includes: an optical compensation element body forming step of forming an optical compensation element body by laminating an optically anisotropic layer on a support; It consists of an oxygen atmosphere optical compensation element body sealing step.

-(Optical compensation element formation process)-
Although the process of forming an optical compensation element is described below, the present invention is not limited to the described method, and an optical compensation element created by another method can also be used.
The optical compensation element body forming step includes a first optical anisotropic layer forming step, an alignment film forming step, a second optical anisotropic layer forming step, a heat treatment step, and a second optical anisotropic layer. Examples include a polymerization curing step process, an antireflection layer forming step, a sealing means forming step, and other layer forming steps.

Hereinafter, each forming step will be described.
-First optical anisotropic layer formation step-
The first optically anisotropic layer forming step is not particularly limited as long as it satisfies the optical characteristics, and can be appropriately selected depending on the purpose. For example, the first optically anisotropic layer forming step can be selected on the support. A step of stacking a plurality of layers having different refractive indexes in a regular order with a normal direction as a stacking direction, and forming a periodic structure stacked body having a repeating structure (repeating repeating units); Preferably mentioned.
The material of the periodic structure laminate is not particularly limited as long as it is an inorganic material, and can be appropriately selected according to the purpose. It is preferable to use a combination of a material having a high refractive index or a material having a low refractive index.
The material having a high refractive index is preferably TiO ₂ , ZrO ₂ or the like, and the material having a low refractive index is preferably SiO ₂ or MgF ₂ . These may be used individually by 1 type and may use 2 or more types together.
Specifically, it is preferably selected from a combination of materials in which the difference in refractive index between the maximum value and the minimum value of the refractive index in the visible light region is 0.5 or more, and a plurality of materials appropriately selected from oxides more preferably a combination of, SiO ₂ combinations (refractive index n = 1.4870-1.5442) and TiO ₂ (refractive index n = 2.583-2.741) is particularly preferred.
The number of layers constituting the repetitive structure is not particularly limited as long as it is a plurality of layers having different refractive indexes, but is preferably formed of two or more layers of two kinds of inorganic materials. More preferably, SiO ₂ and TiO ₂ are alternately deposited on the support using a sputtering apparatus under reduced pressure to form a periodic structure laminate composed of several tens of layers.
The optical thickness of the repeating unit, that is, the thickness in the stacking direction of the repeating structure in the periodic structure stacked body is preferably formed to be thinner than the wavelength of light in the visible light region. Λ / 100 to λ / 5 is preferable, λ / 50 to λ / 5 is more preferable, and λ / 30 to λ / 10 is particularly preferable. Each layer is preferably thin, but the number of laminations increases to obtain the required total thickness. Therefore, when determining the number of laminations of each layer, desired optical characteristics and layers of the first optical anisotropic layer In consideration of coloring problems due to mutual interference, it is preferable that the thickness of each layer be optimized from the material, refractive index, thickness ratio, total thickness, etc. of each layer.
For example, it is preferable to select and form within a range of 400 to 700 nm.
More preferably, the thickness of the first optically anisotropic layer is 100 to 1500 μm.

--Alignment film formation step--
The first alignment film forming step is a step of forming a film having a function of determining an alignment direction of the liquid crystal structure in the second optical anisotropic layer on the first optical anisotropic layer.
The material of the alignment film is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the alignment film made of an organic compound (polymer) subjected to rubbing treatment, the alignment film having a microgroup, Langmuir-Bro Alignment film in which organic compounds such as ω-triconic acid, dioctadecyldimethylammonium chloride, methyl stearylate are accumulated by jet method (LB film), alignment film in which inorganic compounds are obliquely deposited, electric field, magnetic field, light irradiation, etc. An alignment film that generates an alignment function by the above-described method is preferable, and an alignment film made of the rubbed organic compound is preferable.

There is no restriction | limiting in particular as said rubbing process, According to the objective, it can select suitably, For example, the process which rubs the surface of the film | membrane which consists of said organic compound several times in a fixed direction with paper or cloth is mentioned.
The type of the organic compound is not particularly limited and can be determined according to the alignment state (particularly the alignment angle) of the liquid crystal structure. For example, the surface energy of the alignment film for aligning the liquid crystal structure horizontally. Examples thereof include polymers for alignment films that have an effect of not lowering.
As specific examples of the alignment film polymer, in the case of aligning the liquid crystal structure in a direction perpendicular to the rubbing treatment direction, modified polyvinyl alcohol, acrylic acid copolymer, polyimide, polyamic acid, and the like can be given. A polyimide excellent in orientation is more preferable.
There is no restriction | limiting in particular as thickness of the said alignment film, According to the objective, it can select suitably, 0.01-5 micrometers is preferable and 0.02-2 micrometers is more preferable.

-Second optical anisotropic layer formation step-
The first second optically anisotropic layer forming step is a step of forming an optically anisotropic layer using at least a polymerizable liquid crystal compound on the alignment film.
A polymerizable liquid crystal compound solution containing the liquid crystal structure is applied onto the alignment film. As the coating method, it can be formed by a coating method such as a wire bar coating method, a gravure coating method, a micro gravure method or a die coating method. The micro gravure method and the gravure method are preferable from the viewpoint of eliminating drying unevenness by minimizing the wet coating amount, and the forward gravure from the viewpoint of the uniformity of the thickness in the width direction and the uniformity of the thickness in the longitudinal direction over the time of application. The method is more preferred.
The polymerizable liquid crystal compound is not particularly limited and may be appropriately selected depending on the purpose. For example, a polymerizable liquid crystal compound including a liquid crystal structure in which the alignment state can be fixed is preferably used. A polymerizable liquid crystal compound containing a liquid crystal structure such as a discotic liquid crystal structure or a banana-like liquid crystal structure is more preferred, and a polymerizable liquid crystal compound containing a discotic liquid crystal structure is particularly preferred.
Further, the polymerizable liquid crystal compound can contain other components appropriately selected as necessary.
Examples of other components include a polymerization initiator for initiating a polymerization reaction of the polymerizable liquid crystal compound, a solvent for preparing a coating liquid for the polymerizable liquid crystal compound, and the like.

-Heat treatment step-
The heat treatment step is a step in which the second optically anisotropic layer is heated to make the orientation uniform, mature, and maintained.
The coating layer is heated at 60 to 120 ° C. to volatilize and dry the solvent. After drying the solvent, the heating temperature is controlled in the range of 85 to 180 ° C. or until the liquid crystal shows the ND layer in order to ripen the orientation of the polymerization compound containing the liquid crystal structure, and the amount of energy sufficient for the curing reaction to be performed. The polymer compound is polymerized by irradiating with ultraviolet rays to fix the orientation of the polymer compound containing a liquid crystal structure, thereby obtaining an optically anisotropic layer.

-Second optically anisotropic layer polymerization curing step-
The second optical anisotropic layer polymerization curing step is a step of polymerizing and curing the second optical anisotropic layer while maintaining the transition temperature.
The polymerization and curing step of the second optically anisotropic layer having matured orientation is not particularly limited as long as the orientation of the liquid crystal layer can be fixed, and can be appropriately selected according to the purpose. The thing which performs a hardening reaction by irradiating the active ray for photopolymerization is mentioned. As an active ray for photopolymerization, an electron beam, an ultraviolet ray, a visible ray, an infrared ray (heat ray) or the like can be appropriately selected and used as necessary, and an ultraviolet ray is generally preferable. Examples of ultraviolet light sources include low-pressure mercury lamps (sterilization lamps, fluorescent chemical lamps, black lights), high-pressure discharge lamps (high-pressure mercury lamps, metal halide lamps), and short arc discharge lamps (extra-high pressure mercury lamps, xenon lamps, mercury xenon). Lamp).
Examples of radical polymerization initiators for the polymerization reaction of ethylenically unsaturated groups include azobis compounds, peroxides, hydroperoxides, redox catalysts, such as potassium persulfate, ammonium persulfate, tert-butyl peroctoate, and benzoyl. Peroxide, isopropyl percarbonate, 2,4-dichlorobenzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, dicumyl peroxide, azobisisobutyronitrile, 2,2'-azobis (2-amidinopropane) Hydrochloride or benzophenones, acetophenones, benzoins, thioxanthones and the like can be mentioned. Details thereof are described in “Ultraviolet Curing System” General Technical Center, pages 63 to 147, 1989, and the like.

For the polymerization of a compound having an epoxy group, for example, allyl diazonium salts (hexafluorophosphate, tetrafluoroborate, etc.), diallyl iodonium salts, VIa group allylonium salts (PF ₆ , AsF) can be used as UV-activated cationic catalysts. _6, allyl sulfonium salts having an anion such as SbF _6, etc.) are generally used.
In addition, when performing a curing reaction using a radical reaction, in order to avoid a delay in the polymerization reaction due to the presence of oxygen in the air, irradiation with the active ray in a nitrogen atmosphere shortens the reaction time and reduces the amount of light. It is preferable at the point which can be hardened by.

-Antireflection layer formation step-
The antireflection layer forming step is a step of forming an antireflection layer on the cured second optically anisotropic layer. For example, in the case of forming with an inorganic material, a method of forming on the second optically anisotropic layer by a vapor deposition method or in the case of an organic material by a coating method can be mentioned.
The vapor deposition method is not particularly limited and can be appropriately selected according to the purpose. For example, chemical vapor deposition in which a sample is placed in an atmosphere of a gas source and a layer is formed on the sample surface by a chemical reaction. Examples thereof include a physical vapor deposition method (PVD) in which a raw material in the form of particles is attached to a sample by a method (CVD), evaporation or sputtering.
Among these, PVD physically produced by sputtering under reduced pressure using a sputtering target formed of a metal that is a material of the intermediate layer is more preferable.
As the coating method, it can be formed by a coating method such as a wire bar coating method, a gravure coating method, a micro gravure method or a die coating method. The micro gravure method and the gravure method are preferable from the viewpoint of eliminating drying unevenness by minimizing the wet coating amount, and the forward gravure from the viewpoint of the uniformity of the thickness in the width direction and the uniformity of the thickness in the longitudinal direction over the time of application. The method is more preferred.

-Other layer formation steps-
The other layer forming steps include the first optical anisotropic layer forming step, the alignment film forming step, the second optical anisotropic layer forming step, the heat treatment step, and the second optical anisotropic layer polymerization and curing. Steps up to the step are repeated at least once in this order to form a second optical anisotropic layer that forms a second optical anisotropic layer having an orientation direction different from that of the previously formed second optical anisotropic layer. A step for forming a conductive layer.
After the antireflection layer forming step, other layers can be appropriately formed on the antireflection layer, and examples thereof include steps for forming an antiglare layer, an antifouling layer, an antistatic layer, and the like.

―Deoxygenating atmosphere optical compensation element sealing process―
In the deoxygenating atmosphere optical compensation element body sealing step, the optical compensation element body is sandwiched between holding bodies, depressurized and placed in a deoxygenating atmosphere, deaerated, and further replaced with an inert gas. It is a process of sealing the body.
First, a flat plate material is sandwiched so as to cover the entire front and back surfaces of the optical compensation element body, and the optical compensation element body and the plate material are brought into close contact with each other.
Next, the optical compensation element body is heated at 25 to 200 ° C., preferably 25 to 100 ° C., and the work area is depressurized by a generally used vacuum apparatus or decompression apparatus to make a deoxygenated atmosphere. Deaerate the body. Thereby, impurities such as water, oxygen, acidic compounds such as nitrogen oxide and sulfur oxide, and molecules such as various solvent gases generated in the manufacturing process of the optical compensation element are removed.
Further, the gas is filled with an inert gas by a generally used gas replacement device. The inert gas is not particularly limited as long as it is a compound that does not react with the organic material of the optical compensation element body, and can be appropriately selected according to the purpose. Examples of the inert gas include nitrogen gas, helium gas, argon gas, and neon gas. Nitrogen gas is more preferable. These inert gases are preferably as pure as possible.
Then, the exposed side surface of the laminate is sealed with a sealing material. When an ultraviolet curable type is used for the sealing material, the sealing material is coated on the side surface and sealed, and then the sealing material is irradiated with ultraviolet rays to be cured. The light beam preferably excludes a wavelength region of about 300 nm or less. This is because if light in the wavelength region is included, decomposition or deterioration of the liquid crystal structure included in the laminate may be promoted.
When a one-component epoxy resin bonding agent is used for the sealing material, the bonding agent is applied to the side surface and sealed, and then heated at 100 to 150 ° C. for 30 to 60 minutes to accelerate curing. When using a two-component epoxy resin bonding agent, a two-component mixed solution is applied and sealed, and then cured for a predetermined time.
The whole process is hermetically sealed, and the oxidation reaction occurring inside the laminate can be suppressed, fading and deterioration of contrast can be suppressed, and the durability of the optical compensation element can be increased.

―Structure of optical compensation element―
There is no restriction | limiting in particular as a structure of the said optical compensation element, According to the objective, it can select suitably, For example, the optical compensation element of the 1st-8th structure shown below is mentioned suitably.

(Optical compensation element having the first structure)
FIG. 1 is a cross-sectional view of an optical compensation element according to the first structure.
The optical compensation element according to the first structure includes the first optical anisotropic layer on one surface of the support, and the two second optical fibers having different orientation directions on the other surface. It comprises an anisotropic layer. That is, as shown in FIG. 1, the optical compensation element 10 according to the first structure has an alignment film 4A, a second optical anisotropic layer 3A, an alignment film 4B, a first film on one surface of the support 1. The optically anisotropic layer 3B and the antireflection layer 5B are laminated so that the antireflection layer 5B is disposed on the outermost surface, and the first optically anisotropic layer is formed on the other surface of the support 1. 2. The antireflection layer 5A is laminated so that the antireflection layer 5A is disposed on the outermost surface, and the outer surfaces of the antireflection layers 5A and 5B are sandwiched between the holding bodies 6 and 6A, Is sealed with a seal 7.
The first optically anisotropic layer 2 is a periodic structure laminate of a TiO ₂ layer 2A and a SiO ₂ layer 2B, and each layer has a thickness of about 15 nm. The first optical anisotropic layer 2 can also have an antireflection function by using such a periodic structure laminate.
Moreover, it is preferable that the directions of rubbing treatment of the alignment film 4A and the alignment film 4B differ by 90 °. By providing such alignment films 4A and 4B, the alignment directions of the liquid crystal structures included in the polymerizable liquid crystal compound in the second anisotropic layers 3A and 3B can be aligned in directions different by 90 °. Become.

(Optical compensation element having the second structure)
FIG. 2 is a cross-sectional view showing an example of an optical compensation element according to the second structure.
The optical compensation element according to the second structure includes the first optical anisotropic layer and the second anisotropic layer in this order on at least one surface of the support.
That is, as shown in FIG. 2, the optical compensation element 20 according to the second structure has the first optical anisotropic layer 22, the alignment film 24, and the second optical difference on one surface of the support 21. The isotropic layer 23 and the antireflection layer 25B are laminated in this order so that the antireflection layer 25B is disposed on the outermost surface, and the antireflection layer 25A is laminated on the other surface of the support 21. is there. Further, the outer surfaces of the antireflection layers 25A and 25B are sandwiched between holding bodies 26 and 26A, and the outer peripheral side surfaces are sealed with a seal 27.
The structure of the first optical anisotropic layer 22 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
Also, two optical compensation elements 20 according to the second structure can be laminated. In this case, it is preferable that the direction of rubbing treatment of the alignment film in each optical compensation element is different by 90 °.
As shown in the optical compensation element 20 according to the second structure, the mode in which each layer is arranged on one surface of the support depends on the material and combination constituting each layer, but generally has good handling, Manufacturing is also easy.

(Optical compensation element of the third structure)
FIG. 3 is a cross-sectional view showing an example of an optical compensation element according to the third structure.
The optical compensation element according to the third structure is formed by providing two second anisotropic layers having different orientation directions on one surface of the support.
That is, as shown in FIG. 3, the optical compensation element 30 according to the third structure has the first optical anisotropic layer 32, the alignment film 34A, and the second optical difference on one surface of the support 31. The isotropic layer 33A, the alignment film 34B, the second optically anisotropic layer 33B, and the antireflection layer 35B are laminated in this order so that the antireflection layer 35B is disposed on the outermost surface. The antireflection layer 35A is laminated on the surface. Further, the outer surfaces of the antireflection layers 35A and 35B are sandwiched between holding bodies 36 and 36A, and the outer peripheral side surfaces are sealed with a seal 37.
The structure of the first optically anisotropic layer 32 can be the same as that of the first optically anisotropic layer 2 in the optical compensation element 10 according to the first structure.
Further, it is preferable that the rubbing treatment directions of the alignment film 34A and the alignment film 34B are different by 90 °. By providing such alignment films 34A and 34B, the alignment directions of the liquid crystal structure included in the polymerizable liquid crystal compound in the second anisotropic layers 33A and 33B can be aligned in directions different by 90 °. .

(Fourth structure optical compensation element)
FIG. 4 is a cross-sectional view showing an example of an optical compensation element according to the fourth structure.
The optical compensation element according to the fourth structure is formed by providing the two second anisotropic layers having different orientation directions via the support.
That is, as shown in FIG. 4, the optical compensation element 40 according to the fourth structure has the first optical anisotropic layer 42, the alignment film 44A, and the second optical difference on one surface of the support 41. The isotropic layer 43A and the antireflection layer 45B are laminated in this order so that the antireflection layer 45B is disposed on the outermost surface, and the orientation film 44B and the second optical anisotropy are formed on the other surface of the support 41. The layer 43B and the antireflection layer 45A are laminated so as to be arranged in this order. Further, the outer surfaces of the antireflection layers 45A and 45B are sandwiched between holding bodies 46 and 46A, and the outer peripheral side surfaces are sealed with a seal 47.
The structure of the first optical anisotropic layer 42 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
In addition, it is preferable that the rubbing treatment directions of the alignment film 44A and the alignment film 44B are different by 90 °. By providing the alignment film 44A and the alignment film 44B, the alignment direction of the liquid crystal structure included in the polymerizable liquid crystal compound in the second anisotropic layer 43A and the second anisotropic layer 43B is 90 °. It is possible to align in different directions.

(5th structure optical compensation element)
FIG. 5 is a cross-sectional view showing an example of an optical compensation element according to the fifth structure.
The optical compensation element according to the fifth structure comprises the first optical anisotropic layer and the second anisotropic layer on at least one surface of the support.
That is, as shown in FIG. 5, the optical compensation element 50 according to the fifth structure has an alignment film 54, a second optical anisotropic layer 53, and a first optical difference on one surface of a support 51. The isotropic layer 52 and the antireflection layer 55B are laminated in this order so that the antireflection layer 55B is disposed on the outermost surface, and the antireflection layer 55A is laminated on the other surface of the support 51. is there. Further, the outer surfaces of the antireflection layers 55 </ b> A and 55 </ b> B are sandwiched between holding bodies 56 and 56 </ b> A, and the outer peripheral side surfaces are sealed with a seal 57.
The structure of the first optical anisotropic layer 52 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
In addition, two optical compensation elements 50 according to the fifth structure can be stacked. In this case, it is preferable that the direction of rubbing treatment of the alignment film in each optical compensation element is different by 90 °.

(Sixth structure optical compensation element)
FIG. 6 is a cross-sectional view showing an example of an optical compensation element according to the sixth structure.
The optical compensation element according to the sixth structure includes the two second anisotropic layers having different orientation directions.
That is, as shown in FIG. 6, the optical compensation element 60 according to the sixth structure has an alignment film 64A, a second optical anisotropic layer 63A, an alignment film 64B, a first film on one surface of a support 61. The second optically anisotropic layer 63B, the first optically anisotropic layer 62, and the antireflection layer 65B are laminated in this order so that the antireflection layer 65B is disposed on the outermost surface. The antireflection layer 65A is laminated on the surface. Further, the outer surfaces of the antireflection layers 65A and 65B are sandwiched between holding bodies 66 and 66A, and the outer peripheral side surfaces are sealed with a seal 67.
The structure of the first optical anisotropic layer 62 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
In addition, it is preferable that the rubbing treatment directions of the alignment film 64A and the alignment film 64B differ by 90 °. By providing such alignment films 64A and 64B, the alignment directions of the liquid crystal structure included in the polymerizable liquid crystal compound in the second anisotropic layers 63A and 63B can be aligned in directions different by 90 °. Become.

(7th structure optical compensation element)
FIG. 7 is a cross-sectional view showing an example of an optical compensation element according to the seventh structure.
The optical compensation element according to the seventh structure is provided with the two second anisotropic layers having different orientation directions via the support.
That is, as shown in FIG. 7, the optical compensation element 70 according to the seventh structure has an alignment film 74A, a second optical anisotropic layer 73A, and a first optical difference on one surface of a support 71. The isotropic layer 72 and the antireflection layer 75B are laminated in this order so that the antireflection layer 75B is disposed on the outermost surface. The alignment film 74B and the second optical anisotropy are formed on the other surface of the support 71. The layer 73B, the first optical anisotropic layer 72, and the antireflection layer 75A are laminated in this order so that the antireflection layer 75A is disposed on the outermost surface. Further, the outer surfaces of the antireflection layers 75A and 75B are sandwiched between holding bodies 76 and 76A, and the outer peripheral side surfaces are sealed with a seal 77.
The structure of the first optical anisotropic layer 72 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure. Further, it is sufficient that at least one first optical anisotropic layer 72 is provided, and any one of the first optical anisotropic layers 72 can be omitted.
Further, it is preferable that the rubbing treatment directions of the alignment film 74A and the alignment film 74B differ by 90 °. By providing such alignment films 74A and 74B, the alignment direction of the liquid crystal structure included in the polymerizable liquid crystal compound in the second anisotropic layers 73A and 73B can be aligned in directions different by 90 °. Become.

(Eighth structure optical compensation element)
FIG. 8 is a cross-sectional view showing an example of an optical compensation element according to the eighth structure.
An optical compensation element according to an eighth structure includes the first optical anisotropic layer on one surface of the support and the second optical anisotropic layer on the other surface. .
That is, as shown in FIG. 8, the optical compensation element 80 according to the eighth structure includes an alignment film 84, a second optical anisotropic layer 83, and an antireflection layer 85B on one surface of the support 81. The antireflection layer 85B is laminated so as to be disposed on the outermost surface in order, and the first optical anisotropic layer 82 and the antireflection layer 85A are arranged on the other surface of the support 81 in this order. 85A is laminated so as to be disposed on the outermost surface. Further, the outer surfaces of the antireflection layers 85A and 85B are sandwiched between holding bodies 86 and 86A, and the outer peripheral side surfaces are sealed with a seal 87. The structure of the first optical anisotropic layer 82 can be the same structure as the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
Further, two optical compensation elements 80 according to the eighth structure can be used by being laminated. In this case, it is preferable that the direction of rubbing treatment of the alignment film in each optical compensation element is different by 90 °.

In the optical compensation element, the optical characteristics of the first optical anisotropic layers 2, 22, 32, 42, 52, 62, 72, and 82 are determined by the periodic structure pitch of the periodic structure laminate made of an inorganic material. Therefore, it is possible to prevent problems of optical non-uniformity such as refractive index variation and haze value decrease in the surface of the polymer film due to residual stress generated when the polymer film is uniaxially stretched to obtain predetermined optical characteristics. It is possible to increase the optical uniformity in the plane of the first optical anisotropic layer. Therefore, the optical compensation element can optically compensate the liquid crystal layer in the black display state with higher accuracy.
In addition, the first optically anisotropic layer 2, 22, 32, 42, 52, 62, 72, 82 can control the in-plane thickness within a range of several tens of nm, and can realize high smoothness. It is possible to increase the optical uniformity in the plane of the first optical anisotropic layer. Therefore, the liquid crystal layer in the black display state can be optically compensated with higher accuracy, light leakage can be reduced, and the occurrence of stripe-like unevenness can be prevented.
Further, the first optically anisotropic layer 2, 22, 32, 42, 52, 62, 72, 82 does not expand or contract even when used for a long time in a high temperature / high humidity environment.
Further, the outer surfaces of the antireflection layers 5A, 25A, 35A, 45A, 55A, 65A, 75A, 85A and 5B, 25B, 35B, 45B, 55B, 65B, 75B, and 85B are held on the holders 6, 26, 36, and 46, respectively. , 56, 66, 76, 86 and 6A, 26A, 36A, 46A, 56A, 66A, 76A, 86A, respectively, and the impurities attached to the laminate are removed by decompression and inert gas replacement. By sealing the outer peripheral side surface with seals 7, 27, 37, 47, 57, 67, 77, 87, a clean state can be maintained and an oxidation reaction can be suppressed.
The above optical compensation element as a whole can minimize the change in optical characteristics over a long period of time.

  In particular, in the optical compensation elements having the first to third structures, the first optical anisotropy capable of in-plane thickness control in the range of several tens of nanometers on the supports 1, 21 and 31. Layers 2, 22, and 32 are provided. For this reason, the first optically anisotropic layers 2, 22, and 32 can prevent in-plane thickness unevenness with high accuracy, and the first optically anisotropic layer having a highly smooth surface can be used. Can be obtained. Since the second optical anisotropic layers 3, 23, 33 are laminated on the first optical anisotropic layers 2, 22, 32 having such a high smooth surface, the second optical anisotropic layers are stacked. It becomes possible to prevent orientation defects in the plane of the isotropic layers 3, 23, 33. For this reason, an optical compensation element that optically compensates the liquid crystal layer in the black display state with higher accuracy and prevents light leakage at a wide viewing angle can be realized, and a large-screen liquid crystal monitor or liquid crystal that requires a wide viewing angle. By using the optical compensation element in a projector or the like, a liquid crystal display device and a liquid crystal projector with high image quality and high contrast can be realized.

(Liquid crystal display device)
The liquid crystal display device of the present invention includes at least a pair of electrodes, a liquid crystal element having liquid crystal molecules sealed between the pair of electrodes, an optical compensation element disposed on either one or both sides of the liquid crystal element, A polarizing element disposed opposite to the liquid crystal element and the optical compensation element, and further provided with other configurations as necessary, wherein the optical compensation element uses the optical compensation element of the present invention.
The display mode of the liquid crystal element is not particularly limited and can be appropriately selected according to the purpose. For example, a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, an IPS (In-Plane Switching) mode, An OCB (Optically Compensatory Bend) mode, an ECB (Electrically Controlled Birefringence) mode, and the like can be cited. Among them, a TN mode is preferable because of its high contrast ratio.

9 to 12 are schematic configuration diagrams of the liquid crystal display device of the present invention.
In order to facilitate understanding in these drawings, the schematic configuration of the liquid crystal display device shown in each drawing shows a mode in which light from a light source is incident from the lower side of the drawing and is emitted toward the upper side of the drawing. For those including two components of the second optically anisotropic layer, the upper direction of the drawing is referred to as “upper side” and the lower direction of the drawing is referred to as “lower side”. .
As shown in FIG. 9, the liquid crystal display device 100 includes a pair of an upper polarizing element 101 (analyzer) and a lower polarizing element 116 (polarizer) in which absorption axes 102 and 115 are substantially orthogonal and opposed to each other in crossed Nicols. , An optical compensation element 108 disposed between the upper and lower polarizing elements 101 and 116, and a liquid crystal element 114 (liquid crystal cell).
In place of the upper and lower polarizing elements 101 and 116, a polarizing beam splitter such as a Glan-Thompson prism may be used as a polarizing element so as to be opposed to the liquid crystal element 114.

In the liquid crystal element 114, an upper substrate 109 made of a glass substrate and a lower substrate 113 are arranged to face each other, and for example, a nematic liquid crystal 111 is sealed between the upper substrate 109 and the lower substrate 113. On the opposing surfaces of the upper substrate 109 and the lower substrate 113, pixel electrodes (not shown), circuit elements (thin film transistors), and the like are formed. Upper and lower alignment films (not shown) are formed on the opposing surfaces of the upper substrate 109 and the lower substrate 113 that are in contact with the nematic liquid crystal 111. A rubbing process is performed on the surface of the alignment film in contact with the nematic liquid crystal 111 in order to align the alignment direction of the liquid crystal molecules. For example, in the case of a TN mode liquid crystal display device, the rubbing directions 110 and 112 in the upper and lower alignment films are substantially orthogonal to each other as the direction of the groove (rubbing direction) carved by the rubbing treatment.
FIG. 10 shows an alignment state of liquid crystal molecules in a normal state where no voltage is applied to the liquid crystal element 114. The nematic liquid crystals 111 on the upper substrate 109 and the lower substrate 113 are arranged in substantially the same direction as the rubbing directions 110 and 112 by the action of the rubbing treatment applied to the alignment film (not shown). Since the rubbing directions 110 and 112 are orthogonal to each other, the molecules of the nematic liquid crystal 111 are in a state in which the major axis of the liquid crystal molecules is twisted by 90 ° from the upper substrate 109 toward the lower substrate 113. Arranged.

The polarizing element preferably has a light transmittance of 0.001% or less when the polarizing element is arranged in a crossed Nicol state, where the light transmittance when the polarizing element is arranged in parallel Nicols is 100%. .
The upper polarizing element 101 (analyzer) and the lower polarizing element 116 (polarizer) have at least a polarizing film, and further have other configurations as necessary.
The polarizing film is not particularly limited and may be appropriately selected depending on the intended purpose. And a film obtained by adsorbing a dichroic substance such as iodine, azo-based, anthraquinone-based, and tetrazine-based dichroic dyes on the resulting film, and then subjecting the film to stretching orientation.
There is no restriction | limiting in particular as said extending | stretching orientation process, Although it can select suitably according to the objective, The width direction uniaxial stretching type tenter stretching machine in which the absorption axis of the said polarizing film is substantially orthogonal to a longitudinal direction Are preferable. Such a width direction uniaxial stretching type tenter stretching machine has an advantage that foreign matter hardly enters during bonding.
As the stretching orientation treatment, a stretching method described in JP-A No. 2002-131548 can be used.
There is no restriction | limiting in particular as said other structure, Although it can select suitably according to the objective, The transparent protective film which has on one side or both surfaces of the said polarizing film, an antireflection film, an anti-glare treatment film, etc. are mentioned.
The upper and lower polarizing elements 101 and 116 are structured such that a polarizing plate having the transparent protective film on at least one surface of the polarizing film and an optical compensation element 114 as a support on one surface of the optical compensation element. Suitable examples include those having the polarizing film integrally therewith.
There is no restriction | limiting in particular as said transparent protective film, According to the objective, it can select suitably, For example, cellulose esters, such as a cellulose acetate, a cellulose acetate butyrate, a cellulose propionate, a polycarbonate, polyolefin, polystyrene, polyester Etc.
Specific examples of the transparent protective film include polyolefins such as cellulose triacetate, ZEONEX, ZEONOR (both manufactured by Nippon Zeon Co., Ltd.), and ARTON (manufactured by JSR Co., Ltd.).
Further, non-birefringent optical resin materials described in JP-A-8-110402 and JP-A-11-293116 can also be used.
The alignment axis (slow axis) direction of the transparent protective film is not particularly limited, but it is preferable that the alignment axis of the transparent protective film is parallel to the longitudinal direction from the viewpoint of simplicity in operation. Further, the angle between the slow axis (orientation axis) of the transparent protective film and the absorption axis (stretching axis) of the polarizing film is not particularly limited, and can be appropriately set according to the purpose of the polarizing plate. When the polarizing film is produced using the width direction uniaxial stretching type tenter stretching machine, the slow axis (alignment axis) of the transparent protective film and the absorption axis (stretching axis) direction of the polarizing film are It will be substantially orthogonal.
There is no restriction | limiting in particular as retardation of the said transparent protective film, According to the objective, it can select suitably, For example, 10 nm or less is preferable in measurement wavelength 632.8nm, and 5 nm or less is more preferable.
In the case of using the cellulose acetate, the retardation is preferably less than 3 nm, more preferably 2 nm or less, for the purpose of reducing the change in retardation due to environmental temperature and humidity.
The method for producing the polarizing plate is not particularly limited and may be appropriately selected according to the purpose. The polarizing plate is continuously formed so that the longitudinal direction thereof is coincident with the long polarizing film supplied in a roll form. It is preferable that they are bonded together.
Moreover, it is preferable that the polarizing film and the polarizing plate are fixed to the optical compensation element from the viewpoints of preventing displacement of the optical axis and preventing entry of foreign matters such as dust.
There is no restriction | limiting in particular as an antireflection layer, According to the objective, it can select suitably, For example, optical interference films, such as a coating layer of a fluorine-type polymer, a multilayer metal vapor deposition layer, etc. are mentioned.
Is the optical properties and durability (short-term, long-term storage stability) of the upper and lower polarizing elements 101, 116 equivalent to commercially available super high contrast products (for example, HLC2-5618 manufactured by Sanlitz Co., Ltd.)? It is preferable to have more performance.

The optical compensation element 108 uses the optical compensation element of the present invention.
As the optical compensation element, when the white display transmittance of the liquid crystal display device 100 in a state incorporated in the liquid crystal display device 100 is Vw and the black display transmittance is Vb, the white display on the front surface of the liquid crystal display device 100 is performed. The ratio between the transmittance Vw and the black display transmittance Vb, that is, the contrast ratio Vw: Vb is preferably 100: 1 or more, more preferably 200: 1 or more, and further preferably 300: 1 or more.
Further, in all azimuth angle directions inclined by 60 ° from the normal direction on the display surface of the liquid crystal display device 100, the maximum value of the black display transmittance is preferably 10% or less, more preferably 5% or less with respect to Vw. By using such an optical compensation element, it is possible to realize a liquid crystal display device having a wide viewing angle with high contrast and no gradation inversion.
Further, in order to accurately compensate a liquid crystal element having a large residual twist component, the optical compensation element is disposed between a pair of polarizing elements disposed in crossed Nicols, and the normal direction of the optical compensation element is used as a rotation axis. There is no direction in which the liquid crystal display device extinguishes when the optical compensation element is rotated, and the light transmittance is preferably 0.01% or more in all directions.
The optical compensation element 108 is disposed between the upper polarizing element 101 and the liquid crystal element 114, and includes a first optical anisotropic layer 107, an upper second optical anisotropic layer 103, and a lower second optical anisotropic layer. 105.
Each of the optically anisotropic layers constituting the optical compensation element 108 includes a rubbing direction 104 of the alignment film in the upper second optically anisotropic layer 103 and a rubbing direction 110 of the upper alignment film in the upper substrate 109 of the liquid crystal element 114. The rubbing direction 106 of the alignment film in the lower second optically anisotropic layer 105 and the rubbing direction 112 of the lower alignment film in the lower substrate 132 of the liquid crystal element 114 are arranged so that the angle formed by The angle formed by is arranged to be 180 °.
The relationship between the second optically anisotropic layer and the rubbing direction of the alignment film in the substrate of the liquid crystal element may be replaced, and the rubbing direction 106 of the alignment film in the lower second optically anisotropic layer 105; The angle formed between the upper alignment film of the upper substrate 109 of the liquid crystal element 114 and the rubbing direction 110 of the upper alignment film is 180 °, the rubbing direction 104 of the alignment film in the upper second optical anisotropic layer 103, and the liquid crystal element 114 The angle formed with the rubbing direction 112 of the lower alignment film on the lower substrate 113 may be 180 °.
The first optically anisotropic layer 107 is preferably provided so as to be on the liquid crystal element 114 side.

FIG. 11 illustrates a liquid crystal display device in a TN mode in a black display state, that is, an arrangement state of liquid crystal molecules in a state where a voltage is applied to the liquid crystal element 114. When a voltage is applied to the liquid crystal element 114, the alignment state of the liquid crystal molecules changes so that the liquid crystal molecules rise, that is, the major axis of the liquid crystal molecules is perpendicular to the light incident surface. Ideally, it is desirable that all the liquid crystal molecules in the liquid crystal element 114 when a voltage is applied are parallel to the light incident surface, but actually, as shown in FIG. The liquid crystal molecules in the liquid crystal element 114 are gradually in a state where the major axis of the liquid crystal molecules rises from the upper substrate 109 and the lower substrate 113 toward the central region of the liquid crystal element 114. Accordingly, the liquid crystal molecules in the vicinity of the interface between the upper substrate 109 and the lower substrate 113 are arranged in an inclined state in which the major axis of the liquid crystal molecules is not parallel to the light incident surface even when a voltage is applied. Thus, the presence of liquid crystal molecules tilted with respect to the light incident surface may cause light leakage depending on the viewing angle without being in a black display state.
Further, nematic liquid crystal used in a TN mode liquid crystal display device is generally a rod-like liquid crystal and exhibits optically positive uniaxiality. For this reason, even when the liquid crystal molecules exist in the central region of the liquid crystal element 114 and are completely upright, when the liquid crystal display device 100 is viewed from an oblique direction, birefringence is manifested. This may cause light leakage without being displayed.
Therefore, with respect to the alignment state of the liquid crystal in the liquid crystal element 114 near the interface between the upper substrate 109 and the lower substrate 113 in the black display state, the alignment of the liquid crystal molecules included in the second optical anisotropic layers 103 and 105 is performed. The state is specularly symmetric, and optically compensates for the occurrence of birefringence in the interface region on the upper substrate 109 and lower substrate 113 side. The liquid crystal display element 114 in a black display state as a whole is three-dimensionally arranged by being optically compensated by the first optical anisotropic layer 107 having an optical characteristic of a negative refractive index ellipsoid that is not inclined. Thus, optical compensation can be performed to prevent light leakage at a wide viewing angle.
Further, the optical compensation element 108 can be provided on the lower surface of the liquid crystal element 114 as shown in FIG. 11, and further can be provided as 108a and 108b on the upper and lower surfaces of the liquid crystal element 114 as shown in FIG. . Note that in the case of disposing the liquid crystal element on the upper and lower surfaces, either the first optical anisotropic layer 107a or 107b can be omitted, and in the case where the first optical anisotropic layer is provided for each, 107a. , 107b, the total retardation value.
As the optical compensation element 108, the support (not shown) provided in the optical compensation element 108 can be the upper substrate 109 and the lower substrate 113 of the liquid crystal element 114. In this case, the first optical anisotropic layer 107 a or 107 b shown in FIG. 12 is directly formed on the upper substrate 109 and the lower substrate 113.

(LCD projector)
The liquid crystal projector of the present invention is a liquid crystal projector that displays an image by irradiating a liquid crystal display device with illumination light from a light source, and forming an image on a screen by a projection optical system using light modulated by the liquid crystal display device. A liquid crystal display device uses the liquid crystal display device of the present invention.
The liquid crystal projector is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a screen projection type front projector and a rear projection television. The liquid crystal display device used for the liquid crystal projector is not particularly limited and may be appropriately selected depending on the intended purpose. Suitable examples include a transmissive liquid crystal display device and a reflective liquid crystal display device.

FIG. 13 is an external view showing an example of a rear type liquid crystal projector.
As shown in FIG. 13, the liquid crystal projector 200 is provided with a diffusion transmission type screen 203 on the front surface of the housing 202, and an image projected on the back surface is observed from the front surface side of the screen 203. A projection unit 300 is incorporated inside the housing 202, and a projection image projected by the projection unit 300 is reflected by the mirrors 206 and 207 and formed on the back surface of the screen 203. In the liquid crystal projector 200, a tuner circuit (not shown), a well-known circuit unit for reproducing a video signal and an audio signal, and the like are disposed inside the housing 202.
The projection unit 300 incorporates a liquid crystal display device (not shown) as image display means. The liquid crystal display device displays the reproduced image of the video signal, so that the image can be displayed on the screen 203.

FIG. 14 is a configuration diagram showing an example of the projection unit 300.
As shown in FIG. 14, the projection unit 300 includes three transmissive liquid crystal elements 311R, 311G, and 311B, and can perform full-color image projection.
Light emitted from the light source 312 passes through a filter 313 that cuts ultraviolet rays and infrared rays to become white light including red light, green light, and blue light, and illumination light from the light source 312 to the liquid crystal elements 311R, G, and B. It enters the glass rod 314 along the axis. The light incident surface of the glass rod 314 is located near the focal position of the parabolic mirror used in the light source 312, and the light from the light source 312 efficiently enters the glass rod 314.

A relay lens 315 is disposed on the exit surface of the glass rod 314, and the white light emitted from the glass rod 314 becomes parallel light by the relay lens 315 and the subsequent collimator lens 316 and enters the mirror 317.
The white light reflected by the mirror 317 is divided into two light beams by a dichroic mirror 318R that transmits only red light, and the transmitted red light is reflected by the mirror 319 to illuminate the liquid crystal element 311R from the back.
Further, the green light and the blue light reflected by the dichroic mirror 318R are further divided into two light beams by the dichroic mirror 318G that reflects only the green light. The green light reflected by the dichroic mirror 318G illuminates the liquid crystal element 311G from the back side. The blue light transmitted through the dichroic mirror 318G is reflected by the mirrors 318B and 320, and illuminates the liquid crystal element 311B from the back.

  Each of the liquid crystal elements 311R, 311G, 311B is composed of a TN mode liquid crystal element, and each liquid crystal element displays a density pattern image of a red image, a green image, and a blue image constituting a full color image. The A synthesis prism 324 is arranged so that the center is optically equidistant from these liquid crystal elements 311R, 311G, and 311B, and a projection lens 325 is provided to face the emission surface of the synthesis prism 324. Yes. The combining prism 324 includes two dichroic surfaces 324a and 324b inside, and combines the red light transmitted through the liquid crystal element 311R, the green light transmitted through the liquid crystal element 311G, and the blue light transmitted through the liquid crystal element 311B. To enter the projection lens 325.

  A projection lens 325 is provided on the projection optical axis from the center of the exit surface of each of the liquid crystal elements 311R, 311G, 311B, through the center of the combining prism 324 and the projection lens 325 to the center of the screen 3. The projection lens 325 is disposed such that the object-side focal plane coincides with the exit surfaces of the liquid crystal elements 311R, 311G, and 311B, and the image-plane focal plane coincides with the screen 3. Therefore, the full color image synthesized by the synthesis prism 324 is formed on the screen 303.

Polarizing plates 326R, 326G, and 326B are provided on the illumination light incident surfaces of the liquid crystal elements 311R, 311G, and 311B, respectively. Further, optical compensation elements 327R, 327G, and 327B and polarizing plates 328R, 328G, and 328B are provided on the emission surface side of each liquid crystal element. The polarizing plates 326R, 326G, and 326B on the incident surface side and the polarizing plates 328R, 328G, and 328B on the outgoing surface side are arranged in a crossed Nicol arrangement. The polarizing plate on the incident surface side is a polarizer, and the polarizing plate on the outgoing surface side. Acts as an analyzer.
The liquid crystal display device of the present invention includes liquid crystal elements 311R, 311G, 311B, polarizing plates 326R, 326G, 326B, 328R, 328G, 328B, and optical compensation elements 327R, 327G, 327B.
Although the operations of the liquid crystal elements provided for the respective color channels, the polarizing plates and the optical compensation elements respectively provided on both sides thereof are different based on the respective color lights, the basic operations are substantially common. Therefore, the operation will be described below using the red channel.

  The red illumination light reflected by the mirror 319 becomes linearly polarized light by the polarizing plate 326R on the incident surface side and enters the liquid crystal element 311R. In the normally white mode, a signal voltage is applied to the pixel of the TN mode liquid crystal used in the liquid crystal element 311R in order to display black of a red image. At this time, the liquid crystal molecules contained in the liquid crystal layer take various orientations, and even if the red illumination light becomes a parallel light flux and enters the liquid crystal element 311R, the liquid crystal layer exhibits optical rotation and birefringence. The light emitted from the emission surface of the liquid crystal element 311R does not become completely linearly polarized light, and generally elliptically polarized image light is emitted, causing light leakage from the analyzer-side polarizing plate 328R, which is sufficient. I can't get black. Even in the normally black mode, the black level does not become sufficiently black due to a slight inclination of the liquid crystal molecules.

In addition, in the state where black display is desired, if the light passing through the liquid crystal molecules in the liquid crystal element is included obliquely, the image light modulated by the liquid crystal layer has a slightly optical phase different from the linearly polarized light. Becomes elliptically polarized light different from each other, light leakage occurs from the analyzer-side polarizing plate 328R, and sufficient black cannot be obtained.
The liquid crystal projector of the present invention uses the liquid crystal display device of the present invention provided with the optical compensation element of the present invention. The optical compensation element 327R can optically compensate the liquid crystal layer in the black display state with higher accuracy, and can prevent light leakage in a wide viewing angle.
Therefore, the liquid crystal projector of the present invention can obtain a high viewing angle, high contrast, and high image quality.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
Example 1 is an example of the optical compensation element 10 having the first structure shown in FIG. 1. On one surface of the support 1, an alignment film 4 A, a second optical anisotropic layer 3 A, and an alignment film 4 B are provided. The second optical anisotropic layer 3B and the antireflection layer 5B are laminated in this order, and the first optical anisotropic layer 2 and the antireflection layer 5A are laminated on the other surface of the support 1 in this order. In addition, an optical compensation element in which the outer surfaces of the antireflection layers 5A and 5B are sandwiched between the holding bodies 6 and 6A and the outer peripheral side surface is sealed with a seal 7 is provided.

<Production of optical compensation element>
A glass substrate was used as the support 1 to produce an optical compensation element having the above structure.

-First optical anisotropic layer-
A SiO ₂ layer and a TiO ₂ layer are alternately deposited on the glass substrate by using a sputtering apparatus under reduced pressure, and each of the layers is 26 layers, and the first optical structure comprising a periodic structure laminate comprising 52 layers in total. The isotropic layer 2 was formed. The total thickness of the formed first optically anisotropic layer 2 was 760 nm and Rth = 200 nm.

―Preparation of antireflection layer―
An SiO ₂ layer and a TiO ₂ layer were alternately deposited on the surface of the obtained first optically anisotropic layer 2 using a sputtering apparatus under reduced pressure, thereby forming an antireflection layer 5A. The thickness of the formed antireflection layer 5A was 0.24 μm.

―Alignment film―
An alignment film coating solution comprising 20 g of modified polyvinyl alcohol of the following structural formula (3), 360 g of water (solvent), 120 g of methanol, and 1.0 g of glutaraldehyde (crosslinking agent) was prepared.

Next, 100 ml / m ² of the alignment film coating solution is dropped on the surface opposite to the first optically anisotropic layer 2 and spin-coated under the condition of 1000 rpm. Thereafter, the alignment film coating solution was dried with hot air at 100 ° C. for 3 minutes to form an alignment film having a thickness of 600 nm. Next, a rubbing treatment was performed on the formed alignment film to form an alignment film 4A that is aligned in a predetermined alignment direction.

-Preparation of polymerizable liquid crystal compounds-
4.27 g of a discotic liquid crystal compound of the following structural formula (4), 0.42 g of ethylene oxide modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), cellulose acetate butyrate (CAB551-0.2) 0.09 g, manufactured by Eastman Chemical Co., Ltd., 0.02 g of cellulose acetate butyrate (CAB531-1, manufactured by Eastman Chemical Co., Ltd.), 0.14 g of photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy Co., Ltd.), sensitizer 0.05 g (Kayacure DETX-S, manufactured by Nippon Kayaku Co., Ltd.) was dissolved in 15.0 g of methyl ethyl ketone as a solvent to prepare a coating liquid for a polymerizable liquid crystal compound.

A polymerizable liquid crystal compound coating solution 100 ml / m ² is dropped on the surface of the alignment film 4A and spin-coated under the condition of 1500 rpm. Thereafter, the polymerizable liquid crystal compound was aligned by heating in a constant temperature zone of 130 ° C. for 5 minutes. Thereafter, the polymerizable liquid crystal compound was polymerized by UV irradiation with an irradiation energy of 300 mJ / cm ² using a high-pressure mercury lamp, and the alignment state of the liquid crystal structure was fixed. Then, it stood to cool to room temperature and formed the 2nd optically anisotropic layer 3A.
In the formed second optically anisotropic layer 3A, the discotic liquid crystal compound has an angle (orientation angle) formed by a vertical axis normal to the disc surface and a normal to the glass substrate of 10 ° to 62 °. From the glass substrate side toward the air interface side, the discotic liquid crystal compound was hybrid aligned. The orientation angle of the discotic liquid crystal compound is measured by using an ellipsometer (M-150, manufactured by JASCO Corporation) to measure the retardation while changing the observation angle. Was calculated by the method described in “Design Concepts of the Discrete Negative Birefringence Compensation Films SID98 DIGEST”.
On the surface of the second optically anisotropic layer 3A, an alignment film 4B was further laminated so that the alignment direction was substantially orthogonal to the alignment film 4A. Then, the second optical anisotropic layer 3B was formed on the surface of the alignment film 4B by the same method as the second optical anisotropic layer 3A.
The materials, blending amounts, and the like of the alignment film 4B and the second optical anisotropic layer 3B are the same as those of the alignment film 4A and the second optical anisotropic layer 3A.
In the obtained second optically anisotropic layer 3B, the discotic liquid crystal compound has an angle (orientation angle) between the disc surface and the glass substrate of 7 ° to 60 ° from the glass substrate side to the air interface side. The disk-like liquid crystal compound was hybrid aligned. The obtained second optically anisotropic layer 3B was a uniform film free from defects such as schlieren.

―Preparation of antireflection layer―
An SiO ₂ layer and a TiO ₂ layer were alternately deposited on the surface of the obtained second optically anisotropic layer 3B using a sputtering apparatus under reduced pressure to form an antireflection layer 5B. The formed antireflection layer 5B had a thickness of 0.24 μm.

―Sealing of optical compensation element―
Covering the entire front and back surfaces of the optical compensation element made of a glass substrate, the holders 6 and 6A were sandwiched between glass plates similar to the glass plate, and the optical compensation element and the glass plate were brought into close contact with each other. . Next, the working area was depressurized and the optical compensation element was deaerated. Thereby, impurities such as water, oxygen, acidic compounds such as nitrogen oxides and sulfur oxides, and molecules such as various solvent gases generated in the manufacturing process of the optical compensation element are removed.
Furthermore, nitrogen gas was filled. Finally, as a seal 7 on the side surface of the optical compensation element, a one-component epoxy bond (Struct Bond XN-21-SB, manufactured by Mitsui Chemicals, Inc.) is applied and heated at a curing temperature of 100 ° C. for 10 minutes. Cured to seal the optical compensation element.

[Liquid Crystal Display]
Example 1
The manufactured optical compensation element was superimposed on a normally white mode TN mode liquid crystal element with white display of 1.5 V and black display of 3 V to obtain a liquid crystal display device of Example 1.

(Example 2)
A liquid crystal display device of Example 2 was obtained by the same method as in Example 1 except that the method of sealing the optical compensation element was a method of housing the optical compensation element in a glass case and sealing the opening. .

(Example 3)
A liquid crystal display device of Example 3 was obtained in the same manner as in Example 2 except that the optical compensation element was only degassed under reduced pressure and not filled with nitrogen gas.

Example 4
The liquid crystal display device of Example 4 was prepared in the same manner as in Example 2 except that a triacetyl cellulose film having the same retardation value as that of the first optical anisotropic layer was used on the support of the optical compensation element. Obtained.

(Comparative Example 1)
After the optical compensation element was produced by the same method as in Example 4, a corner of the glass case was broken to allow the exchange of substances with the outside to obtain the liquid crystal display device of Comparative Example 1.

(Comparative Example 2)
A liquid crystal display device of Comparative Example 2 was obtained in the same manner as in Example 1 except that the sealing means for the optical compensation element was not used in Example 1.

(Examples 1 to 4 and Comparative Examples 1 and 2)
(Evaluation of contrast of liquid crystal display device)
For the liquid crystal display devices of Examples 1 to 4 and Comparative Examples 1 and 2, the contrast at a location with an elevation angle of 20 ° and an azimuth angle of 45 ° from the front of the display surface was measured using a conoscope (manufactured by Autronic-Melcher). . Here, as the contrast, a contrast (white display illuminance / black display illuminance) calculated from white display illuminance, black display illuminance, and a ratio thereof was measured.

(Examples 5 to 8 and Comparative Examples 3 and 4)
-Production of liquid crystal projector-
The three liquid crystal display devices of Examples 1 to 4 and Comparative Examples 1 and 2 are mounted on a commercially available TN liquid crystal projector for each of the RGB colors, and Examples 5 to 8 and Comparative Examples 3 and 3 are mounted. 4 liquid crystal projectors were produced.

<Evaluation of contrast of LCD projector>
About the obtained liquid crystal projector, the contrast (white display illuminance / black display illuminance) calculated from the white display illuminance, the black display illuminance and the ratio thereof on the screen set at a distance of 3 m from the projection lens was measured.

-Evaluation method of usage time (forced test)-
For the liquid crystal display devices (Examples 1 to 4 and Comparative Examples 1 and 2) and the liquid crystal projectors (Examples 5 to 8 and Comparative Examples 3 and 4), each of 96 hours using white light equivalent to 200 million lux The time of use (forced test) was performed under accelerated conditions, and the contrast was evaluated. The results are shown in Table 1.

Liquid crystal display
From the results in Table 1, it can be seen that the contrast of the liquid crystal display devices of Examples 1 to 4 is not deteriorated as compared with the liquid crystal display devices of Comparative Examples 1 and 2.

LCD projector
From the results of Table 2, it can be seen that the contrast of the liquid crystal projectors of Examples 5 to 8 is not deteriorated as compared with the liquid crystal projectors of Comparative Examples 3 and 4.

  The optical compensation element and the liquid crystal display device of the present invention can be suitably used for mobile phones, personal computer monitors, televisions, liquid crystal projectors, and the like.

FIG. 1 is a cross-sectional view showing an example of the optical compensation element having the first structure. FIG. 2 is a cross-sectional view showing an example of the optical compensation element having the second structure. FIG. 3 is a cross-sectional view showing an example of the optical compensation element having the third structure. FIG. 4 is a cross-sectional view showing an example of an optical compensation element having a fourth structure. FIG. 5 is a cross-sectional view showing an example of the optical compensation element having the fifth structure. FIG. 6 is a cross-sectional view showing an example of an optical compensation element having a sixth structure. FIG. 7 is a cross-sectional view showing an example of an optical compensation element having a seventh structure. FIG. 8 is a sectional view showing an example of an optical compensation element having an eighth structure. FIG. 9 is a schematic view showing an example of the liquid crystal display device of the present invention. FIG. 10 is a schematic view showing an example of the liquid crystal display device of the present invention. FIG. 11 is a schematic view showing an example of the liquid crystal display device of the present invention. FIG. 12 is a schematic view showing an example of the liquid crystal display device of the present invention. FIG. 13 is an external view showing an example of a rear type liquid crystal projector. FIG. 14 is a configuration diagram illustrating an example of a projection unit.

Explanation of symbols

1, 2, 31, 31, 41, 51, 61, 71, 81... Support 2, 22, 32, 42, 52, 62, 72, 82... First optical anisotropic layer 3, 23, 33, 43, 53, 63, 73, 83 ... Second optical anisotropic layer 4, 24, 34, 44, 54, 64, 74, 84 ... Alignment film 5, 25, 35, 45, 55, 65, 75, 85 ... Antireflection layer 6, 26, 36, 46, 56, 66, 76, 86 ... Holder 7, 27, 37 , 47, 57, 67, 77, 87... Seal 10, 20, 30, 40, 50, 60, 70, 80... Optical compensation element 100. ···················································· 101・ Upper polarizing plate absorption axis 103 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Upper second optical anisotropic layer 104 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Upper second optical The rubbing direction during the preparation of the anisotropic layer 105 ......... Lower second optically anisotropic layer 106 ...・ Rubbing direction at the time of preparation of the lower second optically anisotropic layer 107...・ ・ ・ ・ ・ Optical compensation element 109 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Liquid crystal cell upper substrate 110 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Upper substrate liquid crystal alignment rubbing Direction 111 ... Liquid crystal molecules (liquid crystal layer)
112 ·····························································································································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Liquid crystal element 115 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Absorption axis of lower polarizing plate 116・ ・ Lower side polarizing plate 200 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Liquid crystal projector 300 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Projection unit

Claims (9)

  An optical compensation element comprising sealing means for sealing the optical compensation element.   The optical compensation element according to claim 1, wherein the sealing means includes a clamping member that sandwiches the optical compensation element and a sealing means that seals the peripheral side surface.   The optical compensation element according to claim 1, wherein the sandwiching member that sandwiches the optical compensation element is at least one of an inorganic vapor deposition film and glass.   The optical compensation element according to claim 1, wherein the optical compensation element uses a twisted nematic liquid crystal element.   The optical compensation element according to any one of claims 1 to 4, wherein the optical compensation element is a viewing angle widening film. The optical compensation element comprises a first optical anisotropic layer formed of an inorganic material on a support and a second optical anisotropic layer formed of a polymerizable liquid crystal compound,
The first optically anisotropic layer is a periodic structure laminate in which a plurality of layers having different refractive indexes are laminated in a regular order and a repeating unit is repeated, and the negative refractive index anisotropic as a whole. Have
The second optically anisotropic layer is formed of a polymerizable liquid crystal compound including a liquid crystal structure, and has a hybrid orientation in which an orientation angle of the liquid crystal structure changes with respect to a thickness direction of the second optically anisotropic layer. The optical compensation element according to claim 1.   The optical compensation element according to claim 6, wherein the second optical anisotropic layer is composed of two layers having different orientation directions.   A liquid crystal element having at least a pair of electrodes and liquid crystal molecules sealed between the pair of electrodes, an optical compensation element disposed on one or both sides of the liquid crystal element, and opposed to the liquid crystal element and the optical compensation element A liquid crystal display device comprising: a polarizing element disposed, wherein the optical compensation element is the optical compensation element according to claim 1. 9. The liquid crystal display device comprising: a light source; a liquid crystal display device irradiated with illumination light from the light source; and a projection optical system that forms an image of light modulated by the liquid crystal display device on a screen. A liquid crystal projector according to claim 1.