JP2006072150A - Optical anisotropic layer and its manufacturing method, liquid crystal display, and liquid crystal projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical anisotropic layer that can optically compensate for a liquid crystal layer in a state of black display with high precision, and prevent light leak in a wide viewing angle, its manufacturing method, a liquid crystal display having a wide viewing angle and giving a high-quality and high-contrast image, by using an optical compensation element consisting of the optical anisotropic layer, and to provide a liquid crystal projector. <P>SOLUTION: The optical anisotropic layer has at least an orientation film, an intermediate layer are disposed between the organic layers formed of polymerization compounds and showing optical anisotropy; and its manufacturing method is provided. A liquid crystal display which comprises a liquid crystal element, having liquid crystal molecules sealed in a pair of electrodes and between the electrodes, the optically compensated element disposed in one side or both sides of the liquid crystal element, and a polarizing element disposed, in such a manner that it faces the liquid crystal element and the optical compensation element, and a liquid crystal projector that emits illumination light from the light source on the liquid display, focuses the light that has been modulated by the liquid crystal display on the screen by a projection optical system, and displays the image are provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optically anisotropic layer and a method for manufacturing the same, a liquid crystal display device, and a liquid crystal projector.

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. This is a liquid crystal 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 in brightness 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.
A liquid crystal display device that operates in these display modes has a field of view that display characteristics deteriorate due to a decrease in contrast or a gradation inversion phenomenon in which the brightness is reversed in gradation display when the display screen is viewed from an oblique direction. There is a problem of angular dependence.
Such a problem of viewing angle dependency is caused by light leakage even if an attempt is made to display a liquid crystal display device in black, depending on the viewing angle.

Conventionally, the phase difference value of light passing through the liquid crystal layer in the black display state and the phase difference value of the optical anisotropic layer are combined, and the liquid crystal layer in the black display state is optically compensated three-dimensionally, There has been proposed an optical compensation film that eliminates light leakage from any direction and improves the problem of viewing angle dependency.
For example, an optical compensation sheet comprising a transparent 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 has a discotic structure. An optical anisotropy layer comprising a compound having a unit, wherein the disc surface of the discotic structural unit is inclined with respect to the transparent support surface, and the disc surface and the transparent support surface of the discotic structural unit Proposed an optical compensation sheet having a hybrid orientation in which the angle between and the optically anisotropic layer changes in the thickness direction of the optically anisotropic layer, and the transparent support has the characteristics of an optically nearly uniaxial negative refractive index ellipsoid (See Patent Document 1).
According to this optical compensation film, since the discotic structural units of the optically anisotropic layer are arranged so as to be mirror-symmetrical with the liquid crystal layer in the black display state, the transparent support, 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 higher viewing angles and higher contrast are desired for the large screen liquid crystal monitors, liquid crystal projectors, and the like. In particular, a liquid crystal projector is required to have higher contrast because light incident on a liquid crystal cell at various angles is integrated and projected on a screen by a projection lens, and the optical compensation film still has room for improvement. .
That is, in the optical compensation film, a TAC film is used for the transparent support, and it is difficult to make the thickness of the TAC film uniform and to obtain the desired optical characteristics of the TAC film with high accuracy. Therefore, it has been insufficient to optically compensate the liquid crystal layer in the black display state with higher accuracy to prevent light leakage in a wide viewing angle.
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). In the organic layer that optically compensates by forming a plurality of layers of the optical film with an organic material, the alignment film forming coating solution applied on the already laminated optical film has an adverse effect on the optical film, and stable lamination is achieved. I couldn't. In particular, when an alignment film forming coating solution composed of polyimide is used, the solvent in the coating solution penetrates into the optical film, and lacks coating suitability that destroys the surface of the optical film. There was a problem.
As described above, it is insufficient to stably obtain an optical film, and the optical film as a whole is optically compensated for a liquid crystal layer in a black display state with higher accuracy, so that light leaks in a wide viewing angle. It was insufficient to prevent.

JP-A-8-50206 Republished patent WO01 / 090808

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention uses an optically anisotropic layer, a production method for stably obtaining the optically anisotropic layer, and an optical compensation element provided with the optically anisotropic layer. An object of the present invention is to provide a liquid crystal display device and a liquid crystal projector having high viewing angle, high contrast and high image quality by optically compensating with high accuracy and preventing light leakage in a wide viewing angle.

<1> An optically anisotropic layer characterized in that at least an alignment film and an intermediate layer are provided between organic layers having an optical anisotropy formed of a polymerizable compound.
<2> The optically anisotropic layer according to <1>, wherein the intermediate layer is formed of an inorganic material.
<3> The optically anisotropic layer according to any one of <1> to <2>, wherein the intermediate layer is an Al ₂ O ₃ layer and a ZnS layer formed by vapor deposition.
<4> The optically anisotropic layer according to any one of <1> to <3>, wherein the intermediate layer has a thickness of 5 to 5000 nm.
<5> The <1>, wherein the organic layer is formed from a polymerizable liquid crystal compound including a liquid crystal structure, and the orientation angle of the liquid crystal structure is fixed by polymerization in a state inclined with respect to the thickness direction of the organic layer. To <4>.
<6> The optically anisotropic layer according to <5>, wherein the liquid crystal structure in the organic layer has an alignment direction oriented in a certain direction.
<7> The optically anisotropic layer according to <6>, wherein the orientation direction of at least two layers in the organic layer has two layers different from each other.
<8> The optically anisotropic layer according to <7>, wherein two layers having different orientation directions of at least two layers in the organic layer are provided on one surface of the transparent support.
<9> The optically anisotropic layer according to any one of <6> to <8>, having two layers having orthogonal orientation directions.
<10> The optically anisotropic layer according to <9>, wherein the orientation angle is a hybrid orientation that changes in a thickness direction of the organic layer.
<11> The optically anisotropic layer according to any one of <1> to <10>, wherein the liquid crystal structure is a disc shape.
<12> The optically anisotropic layer according to any one of <1> to <10>, wherein the liquid crystal structure has a rod shape.
<13> One organic layer forming step of forming one organic layer exhibiting optical anisotropy on one alignment film;
An intermediate layer forming step of forming an intermediate layer on the organic layer;
An alignment film forming step of forming another alignment film on the intermediate layer;
Forming another organic layer exhibiting optical anisotropy on the other alignment film to form two or more organic layers; and
It is a manufacturing method of the optically anisotropic layer characterized by including.
<14> The method for producing an optically anisotropic layer according to <13>, wherein the intermediate layer is formed using an inorganic material.
<15> The method for producing an optically anisotropic layer according to <14>, wherein Al ₂ O ₃ and ZnS or at least one of them is deposited to form an intermediate layer.
<16> The method for producing an optically anisotropic layer according to <13>, wherein the alignment film is formed by applying an alignment film forming coating solution.
<17> The method for producing an optically anisotropic layer according to <16>, wherein the alignment film forming coating solution contains N-methyl-2-pyrrolidone.
<18> An optically anisotropic layer obtained by the production method according to any one of <13> to <17>.
<19> An optical compensation element comprising both the optically anisotropic layer, the transparent support, and the inorganic optically anisotropic layer according to any one of <1> to <12> and <18>.
<20> The optical compensation element according to <19>, wherein the intermediate layer is located closer to the transparent support than the alignment film adjacent to the intermediate layer.
<21> The optical compensation element according to <19>, wherein both the optically anisotropic layer and the inorganic optically anisotropic layer are provided on at least one surface of the transparent support.
<22> The inorganic 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 has a repeating structure, and the optical thickness of the repeating unit is visible. The optical compensation element according to any one of <19> to <21>, which is shorter than the wavelength of light in the optical region and has negative refractive index anisotropy as a whole of the periodic structure.
<23> The optical compensation element according to any one of <19> to <22>, wherein the inorganic optically anisotropic layer has a retardation Rth represented by the following formula (1) of 20 to 300 nm.
Rth = {(n _x + n _y ) / 2−n _z } × d (1)
However, in said Formula (1), _nx , _ny, and _nz are X, Y, Z orthogonal to each other in an inorganic optical anisotropic layer when the normal line direction of a transparent support body is made into a Z-axis. Represents the refractive index in the axial direction. D represents the thickness of the inorganic optically anisotropic layer.
<24> The optical compensation element according to <22>, wherein the periodic structure laminate is formed by alternately laminating two types of layers having different refractive indexes, and the refractive index difference in the visible light region is 0.5 or more. It is.
<25> The optical compensation element according to any one of <22> to <24>, wherein the periodic structure laminate is an oxide layer.
<26> The optical compensation element according to <25>, wherein the periodic structure laminate is an SiO ₂ layer and a TiO ₂ layer.
<27> 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 <19> to <26>.
<28> The liquid crystal display device according to <27>, wherein the liquid crystal element is a twisted nematic type.
<29> 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 any one of <27> to <28>.

Since the optically anisotropic layer of the present invention comprises an organic layer formed of a polymerizable compound on a transparent support, the liquid crystal layer in a black display state is optically compensated with higher accuracy, Light leakage can be prevented in a wide viewing angle.
Further, the method for producing an optically anisotropic layer according to the present invention comprises: one organic layer forming step of forming one organic layer exhibiting optical anisotropy on one alignment film; and an intermediate layer on the organic layer. An intermediate layer forming step to be formed, an alignment film forming step for forming another alignment film on the intermediate layer, and another organic layer exhibiting optical anisotropy on the other alignment film to form two layers And another organic layer forming step for forming the organic layer as described above.
An optical anisotropy that enables uniform and stable lamination through each process, optically compensates the liquid crystal layer in the black display state with higher accuracy, and prevents light leakage in a wide viewing angle It becomes possible to manufacture a conductive layer.
The liquid crystal display device of the present invention includes a liquid crystal element having at least a pair of electrodes and liquid crystal molecules injected between the pair of electrodes, and an optical anisotropy disposed on either one or both sides of the liquid crystal element. A polarizing element disposed opposite to the liquid crystal element and the optically anisotropic layer, and the optically anisotropic layer is the optically anisotropic layer of the present invention. Can be realized.
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 and high contrast can be achieved.

  According to the present invention, an optically anisotropic layer, a method for stably obtaining the optically anisotropic layer, and an optical compensation element including the optically anisotropic layer are used to solve the above-described problems and The liquid crystal layer in the display state can be optically compensated with higher accuracy, and light leakage can be prevented in a wide viewing angle. Furthermore, it is possible to provide a liquid crystal display device and a liquid crystal projector with a high viewing angle, high contrast, and high image quality.

(Optically anisotropic layer)
In the optically anisotropic layer of the present invention, at least an alignment film and an intermediate layer are provided on the transparent support between the organic layers formed of a polymerizable compound and exhibiting optical anisotropy. The layer is located on the transparent support side of the alignment film.

-Organic layer-
The organic layer includes at least a layer formed of a polymerizable compound and exhibits optical anisotropy, and further includes other configurations appropriately selected as necessary.

The polymerizable compound is not particularly limited and may be appropriately selected depending on the intended purpose. However, it is preferable to use a polymerizable liquid crystal compound containing a liquid crystal molecule capable of fixing the alignment state, and a rod-like liquid crystal structure, a disc A polymerizable liquid crystal compound including a liquid crystal structure or a banana-shaped liquid crystal structure is more preferable, and a polymerizable liquid crystal compound including a disk-shaped liquid crystal structure is particularly preferable.
In addition, the polymerizable 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 molecules are in an aligned state that the average directions of the natural axes of the liquid crystal molecules included in the microscopic area of interest are substantially aligned. Furthermore, in the present invention, when in this alignment state, the average direction of the natural axis of the liquid crystal molecules in the minute region of interest and the stacking direction of the organic layer (normal direction at the interface between the organic layer and the transparent support) The angle formed 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.

Preferred examples of the alignment state include those in which the alignment angle of the liquid crystal molecules is inclined, that is, the alignment angle is not parallel or perpendicular to the thickness direction of the organic layer. More preferably, the organic layer has a hybrid orientation that continuously changes in the thickness direction between the upper surface and the lower surface of the organic 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, the orientation angle near the orientation film side of the liquid crystal molecules in the organic layer, the orientation angle on the air interface side, and the average orientation angle are determined using an ellipsometer (M-150, manufactured by JASCO Corporation). It is an estimated value calculated from the refractive index ellipsoid model by measuring the retardation from the direction, assuming a refractive index ellipsoid model from the measured retardation.
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 can be appropriately selected depending on the purpose. For example, the retardation in the normal direction of the organic layer (Re0), Examples include retardation in the direction of −40 ° (Re-40) and retardation in the direction of + 40 ° (Re40) with respect to the normal direction.
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 (rod-like liquid crystal molecule) is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoates, Examples include cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolans, 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 (I).

但し、前記構造式（１）において、Ｑ^１及びＱ^２は、それぞれ重合性基を表し、Ｌ^１、Ｌ^２、Ｌ^３及びＬ^４は、それぞれ単結合または二価の連結基を表すが、Ｌ^２及びＬ^３の少なくとも一方は、−Ｏ−ＣＯ−Ｏ−を表す。また、Ａ^１及びＡ^２は、それぞれ独立に、炭素原子数２〜２０のスペーサー基を表す。また、Ｍは、メソゲン基を表す。

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 these, the polymerizable liquid crystal compounds having a polymerizable group are 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 containing the liquid crystal structure include compounds represented by the following structural formula (2) as described in JP-A-8-050206.

但し、前記構造式（２）において、Ｄは円盤状コアを表し、Ｌは二価の連結基を表し、Ｐは重合性基を表す。また、ｎは４〜１２の整数である。また、複数の二価の連結基Ｌと重合性基Ｐとの組合せとしては、異なる二価の連結基と重合性基との組合せでもよいが、同一の組合せが好ましい。前記円盤状コアＤとしては、２種以上を併用することも可能である。
前記構造式（２）において、円盤状コアＤの具体例としては、下記構造式（Ｄ１）〜（Ｄ１５）で表される円盤状コアが挙げられる。

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. However, 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-, a divalent group selected from these A divalent linking group in which at least two groups are combined is more preferable, and an alkylene group, alkenylene group, arylene group, -CO-, -O-, or a combination of at least two divalent groups selected from these groups. A valent 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 in 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 type of the polymerization reaction, but is preferably an unsaturated polymerizable group or an epoxy group. More preferably, it is an ethylenically unsaturated polymerizable group. Specific examples of the polymerizable group P include polymerizable groups represented by the following structural formulas (P1) to (P18).

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

The polymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a thermal polymerization initiator that initiates a thermal polymerization reaction and a photopolymerization initiator that initiates a photopolymerization reaction. Of these, the photopolymerization initiator is preferably used.
Specific examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatic acyloin compounds ( U.S. Pat. No. 2,722,512), polynuclear quinone compounds (described in U.S. Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (described in U.S. Pat. Examples thereof include compounds (described in JP-A-60-105667, US Pat. No. 4,239,850) and oxadiazole compounds (described in US Pat. No. 4,212,970).
There is no restriction | limiting in particular as content in the said polymeric liquid crystal compound of the said photoinitiator, Although it can select suitably according to the objective, 0.01-of solid content in the coating liquid of the said polymeric liquid crystal compound It is preferably 20% by weight, and more preferably 0.5 to 5% by weight.
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 is preferably 20~50J / cm ^2, and more preferably 100 to 800 mJ / cm ^2. 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 amides such as N, N-dimethylformamide, sulfoxides such as dimethyl sulfoxide, heterocyclic compounds such as pyridine, hydrocarbons such as benzene and hexane, alkyl halides such as chloroform and dichloromethane, and methyl acetate. Esters such as butyl acetate, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and 1,2-dimethoxyethane, hydroxycarboxylic acid alkyl ester compounds, alkyl substituted alkyl carboxylic acid alkyl ester compounds, and alkyl alkyl acetate compounds Among these, alkyl halides, ketones, hydroxycarboxylic acid alkyl ester compounds, alkoxy-substituted alkylcarboxylic acid alkyl ester compounds, and Le Kill acetate compounds more preferred. 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.

  The other configuration of the optically anisotropic layer is not particularly limited and may be appropriately selected according to the purpose. However, an alignment film for aligning the liquid crystal molecules contained in the polymerizable compound is preferable. Can be mentioned. It is preferable that the polymerizable compound is laminated on the alignment film by coating or the like.

-Alignment film-
The alignment film is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an alignment film made of an organic compound (polymer) that has been rubbed, an alignment film having a microgroup, and 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 of the alignment film may be an alignment film made of the organic compound subjected to the rubbing treatment.

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 molecules. For example, the surface energy of the alignment film for aligning the liquid crystal molecules 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 molecules are 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 compound and the transparent 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 compound and the transparent 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 an alignment film, Although it can select suitably according to the objective, It is preferable that it is 0.01-5 micrometers, and it is more preferable that it is 0.02-2 micrometers.

-Intermediate layer-
The intermediate layer is a layer for protecting the organic layer, and is positioned with the alignment film between the two adjacent organic layers, and is positioned on the transparent support side with respect to the alignment film.
In the optically anisotropic layer in which two or more organic layers are stacked adjacent to each other, an alignment film is formed by applying a coating liquid for forming an alignment film on the already stacked organic layer, and an organic layer is further formed thereon. It becomes a structure to laminate. The intermediate layer serves to prevent the coating solution from contacting the organic layer during the alignment film coating.
In particular, when polyimide having excellent orientation is used for the alignment film, a solvent NMP (N-methyl-2-pyrrolidone) having excellent solubility is included in the coating liquid for forming the alignment film. Since the solubility is strong, when the alignment film forming coating solution is applied to the upper surface of the organic layer, the NMP permeates into the organic layer, and the organic layer is destroyed. The intermediate layer has a function of blocking the penetration of the NMP into the organic layer to prevent such harmful effects, and is located on the transparent support side with respect to the alignment layer on the organic layer. Formed.

The material of the intermediate layer is not particularly limited as long as it has permeation resistance to the solvent of the alignment layer forming coating solution and satisfies the optical characteristics, and can be appropriately selected according to the purpose. For example, an inorganic material etc. are mentioned.
Examples of the inorganic material include TiO _2, SiO ₂ , Al ₂ O ₃ , ZnS, Nb ₂ O ₅ , ZnO, BaTiO _3, etc., but from the viewpoint of permeation resistance, Al ₂ O _3, ZnS, etc. preferable. These may be used individually by 1 type and may use 2 or more types together.

  The shape of the intermediate layer is not particularly limited as long as it can cover the one organic layer, and can be appropriately selected according to the purpose. From the viewpoint of optical properties, a uniform sheet shape is preferable, for example, A uniform sheet shape having the same size as or larger than the upper surface of the one organic layer is preferable.

  There is no restriction | limiting in particular as a structure of the said intermediate | middle layer, According to the objective, it can select suitably, For example, the single layer or laminated | stacked of the same material may be sufficient, and the laminated | stacked of two or more different materials may be sufficient.

The thickness of the intermediate layer is not particularly limited even when a single layer or a laminate is used, such as permeation resistance, optical properties, coloring problems due to mutual interference of layers, refractive index of each layer, thickness ratio, total The thickness can be appropriately selected according to the purpose in consideration of the thickness, etc., but is preferably a thickness that can sufficiently prevent the solvent NMP from penetrating into the organic layer. It is necessary to avoid the occurrence of optical interference between the two layers, so that each layer is preferably thinner.
5-5000 nm is preferable and, as for the thickness of the single layer of the said intermediate | middle layer, or the laminated whole, 50-2000 nm is more preferable.
If the total thickness is less than 5 nm, the solvent may penetrate into the lower layer of the intermediate layer, and if it exceeds 5000 nm, the strength may decrease and the film may easily peel off.
In the case where the intermediate layer has a laminated structure, the thickness of each layer is preferably 5 to 2000 nm, more preferably 50 to 800 nm from the viewpoint of permeation resistance and the like.
If the thickness of each layer is less than 5 nm, the solvent may penetrate into the lower layer of the intermediate layer, and if it exceeds 2000 nm, cracks may occur.

The method for producing the intermediate layer is not particularly limited and may be appropriately selected depending on the purpose. However, in the case of an organic material, a method for producing the intermediate layer by applying a solution for forming an intermediate layer on the alignment film. Are preferable.
The application method is not particularly limited, and examples thereof include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a die coating method, and a spin coating method.
In the case of an inorganic material, the vapor deposition method produced by vapor-depositing material is mentioned suitably.
The vapor deposition method is not particularly limited and may be appropriately selected depending on the purpose. For example, a chemical vapor deposition method in which a sample is placed in an atmosphere of a gas source and a thin film is formed on the sample surface by a chemical reaction. (CVD: Chemical Vapor Deposition) or physical vapor deposition (PVD: Physical Vapor Deposition), in which a raw material in the form of particles is attached to a sample by 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.

The function of the intermediate layer is to prevent the NMP from penetrating into the organic layer and to perform stable lamination while maintaining the uniformity of the upper surface of the organic layer.
In the optically anisotropic layer in which two or more organic layers are laminated adjacent to each other, an alignment film forming coating solution is formed on the already laminated organic layer to form an alignment film, and the organic layer is further laminated thereon. To do.
In particular, when polyimide having excellent orientation is used for the alignment film, the NMP having excellent solubility is contained in the alignment film forming coating solution. When the alignment film forming coating solution is applied to the upper surface of the organic layer, the NMP penetrates into the organic layer, and the organic layer is destroyed. By providing the intermediate layer, such adverse effects can be prevented and a uniform lamination can be stably formed.

-Transparent support-
The transparent support is not particularly limited as long as it is transparent to the extent that it can transmit 50% or more in the wavelength region of light to be used, and can be appropriately selected according to the purpose. For example, white plate glass, blue plate glass, Examples thereof include quartz glass, sapphire glass, and 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, it is preferable that it is 1-99 mol%.
As the polycarbonate copolymer, it is also possible to use repeating units described in WO 00/26705 pamphlet.
As said transparent support body, the glass which consists of the above-mentioned various inorganic material can be used suitably from a viewpoint of the smoothness of a surface.
The thickness of the transparent support is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 0.1 μm or more, and the upper limit of the thickness is built-in handling properties or mechanical From the viewpoint of strength, 0.3 mm to 3 mm is preferable, and 0.5 mm to 1.5 mm is more preferable.

-Manufacturing method of optically anisotropic layer-
The manufacturing method of the optically anisotropic layer of the present invention includes a manufacturing method including one organic layer forming step, an intermediate layer forming step, an alignment film forming step, and another organic layer forming step.

-One organic layer formation process-
One organic layer forming step is a step of forming one organic layer in the order of one alignment film forming step and one organic layer forming step.
--One alignment film formation step--
The one alignment film forming step is a step of forming a film having a function of determining an alignment direction of the liquid crystal molecules in the organic layer on the transparent support.
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 or the like in which an alignment function is generated by the above-mentioned method is preferable, and an alignment film made of the organic compound subjected to the rubbing treatment 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 molecules. Examples thereof include polymers for alignment films that have an effect of not lowering.
Specific examples of the alignment film polymer include modified polyvinyl alcohol, acrylic acid copolymer, polyimide, and polyamic acid when the liquid crystal molecules are aligned in a direction orthogonal to the rubbing treatment direction. A polyimide having excellent orientation is more preferable.

  There is no restriction | limiting in particular as thickness of the said alignment film, Although it can select suitably according to the objective, 0.01-5 micrometers is preferable and 0.02-2 micrometers is more preferable.

--- One organic layer formation step--
The one organic layer forming step is a step of forming an organic layer using at least a polymerizable compound on the alignment film.
The polymerizable compound is not particularly limited and may be appropriately selected depending on the intended purpose.For example, it is preferable to use a polymerizable compound including a liquid crystal structure capable of fixing the alignment state, a rod-like liquid crystal structure, A polymerizable liquid crystal compound containing a discotic liquid crystal structure, a banana-like liquid crystal structure or the like is more preferable, and a polymerizable liquid crystal compound including a discotic liquid crystal structure is particularly preferable.
In addition, the polymerizable 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 compound, a solvent for preparing a coating liquid for the polymerizable compound, and the like.
The polymerizable compound solution containing the liquid crystal structure is applied onto an alignment film described later using a bar coater, spin coater, die coater or the like. Next, the coating layer is heated to dry the solvent, and then the heating temperature is changed to ripen the orientation of the polymerizable compound containing a liquid crystal structure, and then the ultraviolet light is irradiated to polymerize the polymerized compound. Then, the orientation of the liquid crystal molecules is fixed and the organic layer is formed.
-Intermediate layer formation process-
The intermediate layer forming step is a step of forming an optically uniform and permeation-resistant layer between the organic layer and the other alignment film.

There is no restriction | limiting in particular as a method of forming the said intermediate | middle layer, According to the objective, it can select suitably. In the case of an organic material, a method of forming an intermediate layer by applying an intermediate layer forming solution on the alignment film is preferable. The coating method is not particularly limited, and examples thereof include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a die coating method, and a spin coating method.
In the case of an inorganic material, the vapor deposition method formed by vapor-depositing material is mentioned suitably.
There is no restriction | limiting in particular as said vapor deposition method, According to the objective, it can select suitably, For example, the said chemical vapor deposition method (CVD), physical vapor deposition method (PVD), etc. are mentioned.
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.

  The shape of the intermediate layer is not particularly limited as long as it can cover the one organic layer, and can be appropriately selected according to the purpose. From the viewpoint of optical properties, a uniform sheet shape is preferable, for example, A uniform sheet shape having the same size as or larger than the upper surface of the one organic layer is preferable.

  There is no restriction | limiting in particular as a structure of the said intermediate | middle layer, According to the objective, it can select suitably, For example, the single layer or laminated | stacked of the same material may be sufficient, and the laminated | stacked of two or more different materials may be sufficient.

The thickness of the intermediate layer is not particularly limited even when a single layer or a laminate is used, such as permeation resistance, optical properties, coloring problems due to mutual interference of layers, refractive index of each layer, thickness ratio, total The thickness can be appropriately selected according to the purpose in consideration of the thickness, etc., but is preferably a thickness that can sufficiently prevent the solvent NMP from penetrating into the organic layer. It is necessary to avoid the occurrence of optical interference between the two layers, so that each layer is preferably thinner.
5-5000 nm is preferable and, as for the thickness of the single layer of the said intermediate | middle layer, or the laminated whole, 50-2000 nm is more preferable.
If the total thickness is less than 5 nm, the solvent may penetrate into the lower layer of the intermediate layer, and if it exceeds 5000 nm, the strength may decrease and the film may easily peel off.
In the case where the intermediate layer has a laminated structure, the thickness of each layer is preferably 5 to 2000 nm, more preferably 50 to 800 nm from the viewpoint of permeation resistance and the like.
If the thickness of each layer is less than 5 nm, the solvent may penetrate into the lower layer of the intermediate layer, and if it exceeds 2000 nm, cracks may occur.

-Alignment film formation process-
The alignment film forming step is a step of forming an alignment film similar to the one alignment film, and the other alignment film is formed to have the same thickness by the same material and method as the alignment film formation method. However, it is preferable that the rubbing treatment is performed so that the alignment direction differs by 90 ° with respect to the one alignment film. By the rubbing treatment, the alignment directions of the liquid crystal molecules contained in the polymerizable compound in one organic layer and the other organic layer can be aligned in directions different by 90 °, and optical characteristics can be improved.
―Other organic layer formation process―
The other organic layer forming step is a step of forming an organic layer similar to the one organic layer on the other alignment film, and the same material and method as the method for forming the one organic layer are used. The other organic layer is formed to have a thickness.

―Optical compensation element―
The optical compensation element of the present invention comprises both the optically anisotropic layer and the inorganic optically anisotropic layer on at least one surface of the transparent support. It has other layers as needed.

-Inorganic optical anisotropic layer-
As the structure of the inorganic optically anisotropic layer laminated on the optically anisotropic layer or transparent support of the present invention, any structure can be used as long as it is formed of an inorganic material and has an optical anisotropy as a whole layer. There is no particular limitation and can be appropriately selected according to the purpose.For example, with the normal direction of the transparent support as the lamination direction, a plurality of layers having different refractive indexes are laminated in a regular order and repeated. A periodic structure laminate having a structure (repeating repeating units), and the optical thickness of the repeating unit, that is, the thickness of the repeating structure in the periodic structure laminate in the stacking direction (hereinafter referred to as “periodic structure”). A structure having a shorter pitch than a wavelength of light in the visible light region is 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, and the inorganic optical anisotropic layer is allowed to pass through. It is also possible to make it different depending on the nature of light.

The number of layers constituting the one repetitive structure is not particularly limited as long as it is a plurality 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. Λ is preferably λ / 100 to λ / 5, more preferably λ / 50 to λ / 5, and particularly preferably λ / 30 to λ / 10.
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 thin films, the thickness of each layer is preferably thin, but the required total thickness is obtained. However, when determining the thickness of each layer, considering the desired optical characteristics of the inorganic optical anisotropic layer, coloring problems due to mutual interference of thin films, etc., the material of each layer, It is preferable that the optimum value of the thickness of each layer is determined from the 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 visible 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 inorganic optically anisotropic layer, the retardation Rth represented by the following formula (1) is preferably 20 to 300 nm, and more preferably 20 to 200 nm.
Rth = {(n _x + n _y ) / 2−n _z } × d (1)
However, in the formula (1), _nx , _ny, and _nz are X, Y, and Z, which are orthogonal to each other in the inorganic optically anisotropic layer when the normal direction of the transparent support is the Z axis. Refractive index in the Z-axis direction is shown respectively. D represents the thickness of the inorganic 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.
As thickness of the said inorganic optically anisotropic layer, what satisfy | fills the said retardation is preferable, and 50-2000 micrometers is specifically preferable, and 100-1500 micrometers is more preferable.

The material of the periodic structure laminate constituting the inorganic optically anisotropic layer is not particularly limited and may be appropriately selected depending on the purpose. Since the phase difference value is determined by the product of the thickness d of the inorganic optically anisotropic layer and the refractive index difference Δn of each layer constituting the repetitive structure, it is preferably selected as appropriate according to the desired refractive index difference Δn. Specifically, it is preferable that the material having a high refractive index is appropriately selected from SiO ₂ , MgF _{2 and the} like as the material having a low refractive index, such as TiO ₂ and ZrO ₂ .
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. More preferably, it is a combination of a plurality of materials appropriately selected from oxide films, and a SiO ₂ (refractive index n = 1.870 to 1.5442) film and a TiO ₂ (refractive index n = 2.583-2). .741) A combination of membranes is particularly preferred.

When the refractive index difference Δn is less than 0.5, the thickness d of the inorganic optically anisotropic layer is adjusted, and the retardation value in the inorganic optically anisotropic layer becomes a desired value. The process of laminating repeating units is increased, which is not preferable in consideration of manufacturability and productivity.
Such an inorganic optically anisotropic layer is equivalent to a medium having a uniform refractive index in the stacking direction of the multilayer film, that is, in the normal direction of the transparent support. 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 inorganic optically anisotropic layer has high smoothness and facilitates the retardation and the like by appropriately selecting the material, thickness, number of layers, period of the periodic structure pitch, etc. of the periodic structure laminate. In addition, it can be obtained with high accuracy.

The inorganic optically anisotropic layer can also be given a function as an antireflection layer by appropriately selecting the film thickness ratio and thickness of the multilayer film.
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.

-Other layers-
The other layers are not particularly limited and can be appropriately selected depending on the purpose. For example, an antireflection layer and various filter layers can be provided. Examples include a glare layer, an antifouling layer, and an antistatic layer.

-Antireflection layer-
The antireflection layer is not particularly limited and may be appropriately selected depending on the purpose. For example, the reflection layer is composed of a support, a hard coat layer, an antiglare hard coat layer, and a low refractive index layer. Antireflection layer, antireflection layer composed of support, hard coat layer, middle refractive index layer, high refractive index layer, low refractive index layer (outermost layer), known AR film (Anti Reflection Coat Film), etc. Is mentioned.
In the former antireflection layer, the matte particles are dispersed in the antiglare hard coat layer, and the refractive index of materials other than the matte particles forming the antiglare hard coat layer is 1.50 to 2.00. The refractive index of the low refractive index layer is preferably 1.35 to 1.49. Further, the hard coat layer may be a hard coat layer having antiglare properties as described above, a hard coat layer having no antiglare properties, or one layer, or a plurality of layers, for example, 2 to 4 layers. Although it may be constituted, the low refractive index layer is coated on the outermost layer.
Examples of the latter antireflection layer include those in which the support, the middle refractive index layer, the high refractive index layer, and the low refractive index layer have a refractive index that satisfies the following relationship.
Refractive index of the high refractive index layer> Refractive index of the medium refractive index layer> Refractive index of the support> Refractive index of the low refractive index layer

-Structure of optical compensation element-
There is no restriction | limiting in particular as a structure of the said optical compensation element, Although it can select suitably according to the objective, For example, the optical compensation element of the 1st to 4th 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 two organic layers having different alignment directions provided on one surface of the transparent support. That is, the optical compensation element according to the first structure includes the inorganic optically anisotropic layer and the optically anisotropic layer in this order on at least one surface of the transparent support.
That is, as shown in FIG. 1, the optical compensation element 10 according to the first structure has an inorganic optical anisotropic layer 2, an alignment film 4, an organic layer 3, an intermediate layer on one surface of the transparent support 1. 6, the alignment film 4A, the organic layer 3A, and the antireflection layer 5A are laminated in this order so that the antireflection layer 5A is disposed on the outermost surface, and the antireflection layer 5 is formed on the other surface of the transparent support 1. It is formed by stacking. The inorganic optically anisotropic layer 2 is a periodic structure laminate of a TiO ₂ layer and a SiO ₂ layer, and each layer has a thickness of about 15 nm.
The inorganic optical anisotropic layer 2 can also have an antireflection function by using such a periodic structure laminate.
The intermediate layer 6 is formed by evaporating Al ₂ O ₃ or ZnS, and has a thickness of about 100 nm. Further, it is preferable that the direction of rubbing treatment between the alignment film 4 and the alignment film 4A is 90 °.
By providing the alignment film 4 and the alignment film 4A, the alignment directions of the liquid crystal molecules contained in the polymerizable compound in the organic layer 3 and the organic layer 3A can be aligned in directions different by 90 °. It becomes possible. In addition, two optical compensation elements 10 according to the first structure can be stacked. As shown in the optical compensation element 10 according to the first structure, the mode in which each layer is disposed on one surface of the support depends on the material constituting each layer and the combination, but generally handling is good, Manufacturing is also easy.

(Optical compensation element having the second structure)
FIG. 2 is a cross-sectional view of an optical compensation element according to the second structure. The optical compensation element according to the second structure is formed by providing two organic layers having different orientation directions on one surface of the transparent support. That is, as shown in FIG. 2, the optical compensation element 20 according to the second structure has an alignment film 24, an organic layer 23, an intermediate layer 26, an alignment film 24 </ b> A, an organic layer on one surface of the transparent support 21. 23A, the inorganic optically anisotropic layer 22, and the antireflection layer 25A are laminated in this order so that the antireflection layer 25A is disposed on the outermost surface, and the antireflection layer is formed on the other surface of the transparent support 21. 25 is laminated. The inorganic optically anisotropic layer 22 may have the same structure as that of the inorganic optically anisotropic layer 2 in the optical compensation element 10 according to the first structure.
The intermediate layer 26 may have the same material, thickness, and structure as the intermediate layer 6 in the optical compensation element 10. Similarly to the optical compensation element 10, it is preferable that the rubbing treatment directions of the alignment film 24 and the alignment film 24 </ b> A differ by 90 °.
By providing the alignment film 24 and the alignment film 24A, the alignment directions of the liquid crystal molecules contained in the polymerizable compound in the organic layer 23 and the organic layer 23A can be aligned in directions different by 90 °. It becomes.

(Optical compensation element of the third structure)
FIG. 3 is a cross-sectional view of an optical compensation element according to the third structure. The optical compensation element according to the third structure is formed by providing the two organic layers having different orientation directions through the transparent support.
That is, as shown in FIG. 3, the optical compensation element 30 according to the third structure has an alignment film 34, an organic layer 33, an intermediate layer 36, an alignment film 34 </ b> A, an organic layer on one surface of the transparent support 31. 33A and the antireflection layer 35A are formed in this order, and the antireflection layer 35A is laminated so as to be disposed on the outermost surface. On the other surface of the transparent support 31, an alignment film 34B, an organic layer 33B, an inorganic optical anisotropic layer 32, and an antireflection layer 35 are laminated so as to be arranged in this order. The inorganic optically anisotropic layer 32 may have the same structure as that of the inorganic optically anisotropic layer 2 in the optical compensation element 10 according to the first structure.
The intermediate layer 36 can have the same material, thickness, and structure as the intermediate layer 6 in the optical compensation element 10. Similarly to the optical compensation element 10, it is preferable that the rubbing treatment directions of the alignment film 34 and the alignment film 34A differ by 90 °. By providing the alignment film 34 and the alignment film 34A, the alignment directions of the liquid crystal molecules contained in the polymerizable compound in the organic layer 33 and the organic layer 33A can be aligned in directions different by 90 °. It becomes possible.

(Fourth structure optical compensation element)
FIG. 4 is a cross-sectional view of an optical compensation element according to the fourth structure. The optical compensation element according to the fourth structure includes the inorganic optically anisotropic layer and the optically anisotropic layer on both surfaces of the transparent support. That is, as shown in FIG. 4, the optical compensation element 40 according to the fourth structure has an alignment film 44, an organic layer 43, an intermediate layer 46, an alignment film 44A, an organic layer on one surface of the transparent support 41. 43A, the inorganic optically anisotropic layer 42, and the antireflection layer 45A are laminated in this order so that the antireflection layer 45A is disposed on the outermost surface. On the other surface of the transparent support 41, an alignment film 44B, an organic layer 43B, an inorganic optical anisotropic layer 42A, and an antireflection layer 45 are laminated.
The inorganic optically anisotropic layer 42 is a periodic structure laminate of a TiO ₂ layer and a SiO ₂ layer, and each layer has a thickness of about 15 nm.
The intermediate layer 46 may have the same material, thickness, and structure as the intermediate layer 6 in the optical compensation element 10. Further, it is preferable that the direction of rubbing treatment between the alignment film 44 and the alignment film 44A be 90 ° different. By providing the alignment film 44 and the alignment film 44A, the alignment directions of the liquid crystal molecules contained in the polymerizable compound in the organic layer 43 and the organic layer 43A can be aligned in directions different by 90 °. It becomes possible.

In the optical compensation element, the optical characteristics of the inorganic optically anisotropic layers 2, 22, 32, and 42 are determined by the periodic structure pitch of the periodic structure laminate made of an inorganic material. Therefore, the problem of optical non-uniformity such as refractive index variation in the surface of the polymer film due to residual stress generated when the polymer film is uniaxially stretched to obtain the predetermined optical characteristics and haze value decrease is prevented. It is possible to increase the optical uniformity in the plane of the inorganic optically 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 inorganic optically anisotropic layers 2, 22, 32, and 42 can control the in-plane thickness within a range of several tens of nanometers, and can realize high smoothness. It is possible to increase the optical uniformity in.
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 streaky irregularities can be prevented. Further, the inorganic optically anisotropic layer 2, 22, 32, 42 does not expand or contract even when used for a long time in a high temperature and high humidity environment, and the optical compensation element as a whole has long optical characteristics. Can be minimized.

  The optical compensation element having each structure is provided on the transparent supports 1, 21, 31, and 41. The inorganic optically anisotropic layers 2, 22, 32, and 42 capable of controlling the thickness in the plane within a range of several tens of nanometers. It is equipped with. Therefore, the inorganic optically anisotropic layers 2, 22, 32 and 42 can prevent in-plane thickness unevenness with high accuracy, and obtain an inorganic optically anisotropic layer having a highly smooth surface. It becomes possible. In particular, in the optical compensation element having the first structure, the organic layer 3 is laminated on the inorganic optical anisotropic layer 2 having such a highly smooth surface. It becomes possible to prevent alignment defects. Further, by laminating the intermediate layers 6, 26, 36 and 46, a uniform and stable lamination can be obtained without destroying the organic layers 3, 23, 33 and 43. 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 and 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 given. Among them, the TN mode is preferable because of high contrast.

FIG. 5 is a schematic configuration diagram of the liquid crystal display device of the present invention. As shown in FIG. 5, the liquid crystal display device 100 includes a pair of an upper polarizing element 101 (analyzer) and a lower polarizing element 103 (polarizer) in which absorption axes 102 and 104 are substantially orthogonal and opposed to each other in crossed Nicols. Between the upper and lower polarizing elements 101 and 103 and between the upper and lower optical compensating elements 110 and 120 and the pair of the upper and lower optical compensating elements 110 and 120, respectively. The liquid crystal element 130 (liquid crystal cell) is provided.
In place of the upper and lower polarizing elements 101 and 103, a polarizing beam splitter such as a Glan-Thompson prism may be used as a polarizing element so as to face the liquid crystal element 130.

  In the liquid crystal element 130, an upper substrate 131 made of a glass substrate and a lower substrate 132 are arranged to face each other, and a nematic liquid crystal 136 is sealed between the upper substrate 131 and the lower substrate 132. On the opposing surfaces of the upper substrate 131 and the lower substrate 132, pixel electrodes, circuit elements (thin film transistors) and the like (not shown) are formed. Upper and lower alignment films (not shown) are formed on the opposing surfaces of the upper substrate 131 and the lower substrate 132 that are in contact with the nematic liquid crystal 136. A rubbing process is performed on the surface of the alignment film in contact with the nematic liquid crystal 136 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 134 and 135 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. 5 shows an alignment state of liquid crystal molecules in a normal state where no voltage is applied to the liquid crystal element 130. The nematic liquid crystals 136 on the upper substrate 131 and the lower substrate 132 are arranged in substantially the same direction as the rubbing directions 134 and 135 by the action of a rubbing process performed on the alignment film (not shown). Since the rubbing directions 134 and 135 are orthogonal to each other, the molecules of the nematic liquid crystal 136 are in a state in which the major axis of the liquid crystal molecules is twisted by 90 ° from the upper substrate 131 toward the lower substrate 132. Are arranged as follows.

The polarizing element has a light transmittance of 0.001% or less when the polarizing element is arranged in a crossed Nicol state when the light transmittance when the polarizing element is arranged in parallel Nicols is 100%. It is preferable.
The upper polarizing element 101 (analyzer) and the lower polarizing element 103 (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 layer, a glare-proof process film, etc. are mentioned.
As the structures of the upper and lower polarizing elements 101 and 103, a polarizing plate having the transparent protective film on at least one surface of the polarizing film, the upper optical compensation element 110, and the lower optical compensation element 120 are supported. Preferred examples include those having the polarizing film integrally on one surface of the optical compensation element.

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.
When the cellulose acetate is used, the retardation is preferably less than 3 nm, and more preferably 2 nm or less, for the purpose of reducing the change in retardation due to environmental temperature and humidity.
There is no restriction | limiting in particular as a preparation method of the said polarizing plate, Although it can select suitably according to the objective, It is continuous so that a longitudinal direction may correspond with respect to the elongate polarizing film supplied with a roll form. It is preferable that the two are bonded together.
It is preferable that the polarizing film and the polarizing plate are fixed to the upper optical compensation element 110 and the lower optical compensation element 120 in terms of prevention of optical axis misalignment and prevention of entry of foreign matter such as dust.
There is no restriction | limiting in particular as said sticking process method, According to the objective, it can select suitably, For example, the adhesion process through a transparent contact bonding layer, the joining process through a transparent adhesion layer, etc. are mentioned.
The transparent adhesive layer is not particularly limited and may be appropriately selected depending on the purpose.From the viewpoint of preventing changes in optical properties of the constituent members, a high-temperature process is required for curing and drying during the adhesion process. Those which do not require are preferable, and those which do not require a long curing treatment or drying time are more preferable. Specific examples of the transparent adhesive layer include hydrophilic polymer adhesives and pressure-sensitive adhesives.
The transparent adhesive layer is not particularly limited and may be appropriately selected depending on the intended purpose. However, acrylic polymers, silicone polymers, polyesters, polyurethanes, polyethers, synthetic rubbers and the like are preferable, and optical transparency Acrylic polymers are more preferable from the viewpoints of adhesive properties, weather resistance, and the like.
The transparent adhesive layer is preferably temporarily attached with a separator or the like to prevent contamination of the adhesive layer surface.

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 film of a fluorine-type polymer, a multilayer metal vapor deposition film, etc. are mentioned.
The optical properties and durability (short-term and long-term storage stability) of the upper and lower polarizing elements 101 and 103 are the same as those of a commercially available super high contrast product (for example, HLC2-5618 manufactured by Sanlitz Co., Ltd.). It is preferable to have more performance.

The upper optical compensation element 110 and the lower optical compensation element 120 use 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 the state of being incorporated in the liquid crystal display device 100 is Vw and the black display transmittance is Vb, the white color in front of the liquid crystal display device 100 is used. The ratio between the display 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 more preferably 300: 1 or more. Is more preferable.
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 with respect to Vw, and is preferably 5% or less. More preferably. 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 is extinguished when the optical compensation element is rotated, and the light transmittance is preferably 0.01% or more in all directions.

The upper optical compensation element 110 is provided between the upper polarizing element 101 and the liquid crystal element 130 such that the inorganic optical anisotropic layer 112 is on the liquid crystal element 130 side.
In the upper optical compensation element 110, an angle formed between a rubbing direction of an alignment film (not shown) in the organic layer 113 and a rubbing direction of an upper alignment film (not shown) in the upper substrate 131 of the liquid crystal element 130 is 180 °. It is arranged to become.
The lower optical compensation element 120 is provided between the lower polarizing element 103 and the liquid crystal element 130 such that the inorganic optical anisotropic layer 122 is on the liquid crystal element 130 side.
The lower optical compensation element 120 has an angle formed by a rubbing direction of an alignment film (not shown) in the organic layer 123 and a rubbing direction of a lower alignment film (not shown) on the lower substrate 132 of the liquid crystal element 130. It arrange | positions so that it may become 180 degrees.
Further, the organic layers 113 and 123 can be provided on the upper and lower surfaces of the liquid crystal element 130 as shown in FIG.
In addition, in the case where the organic layers 113 and 123 are provided so as to overlap the upper surface or the lower surface of the liquid crystal element 130, the inorganic optical anisotropic layer 112 or 122 provided in either the upper or lower optical compensation element 110 or 120. Either of these can be omitted.
As the optical compensation elements 110 and 120, the transparent support (not shown) provided in the optical compensation elements 110 and 120 may be the upper substrate 131 and the lower substrate 132 of the liquid crystal element 130. . In this case, the inorganic optically anisotropic layer 112 or 122 shown in FIG. 6 is directly formed on the upper substrate 131 and the lower substrate 132.

  FIG. 6 illustrates a liquid crystal display device in a TN mode in a black display state, that is, an alignment state of liquid crystal molecules in a state where a voltage is applied to the liquid crystal element 130. When a voltage is applied to the liquid crystal element 130, the alignment state of the liquid crystal molecules is changed 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 130 when a voltage is applied are parallel to the light incident surface, but in practice, as shown in FIG. The liquid crystal molecules in the liquid crystal element 130 are gradually in a state where the major axis of the liquid crystal molecules rises from the upper substrate 131 and the lower substrate 132 toward the central region of the liquid crystal element 130. Accordingly, the liquid crystal molecules in the vicinity of the interface between the upper substrate 131 and the lower substrate 132 are in an inclined alignment state even when a voltage is applied, in which the major axis of the liquid crystal molecules is not parallel to the light incident surface. . 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. Therefore, even when the liquid crystal molecules exist in the central region of the liquid crystal element 130 and are completely raised, when the liquid crystal display device 100 is viewed from an oblique direction, birefringence is expressed, and depending on the viewing angle, This may cause light leakage without black display.
Therefore, with respect to the alignment state of the liquid crystal in the liquid crystal element 130 in the vicinity of the interface between the upper substrate 131 and the lower substrate 132 in the black display state, the alignment state of the liquid crystal molecules contained in the organic layers 113 and 123 is mirror-finished. Symmetrically, it optically compensates for the occurrence of birefringence in the interface region on the upper substrate 131 and lower substrate 132 side, and is uniaxially inclined with respect to birefringence due to liquid crystal in the central region of the liquid crystal element 130. Optical compensation is performed by the inorganic optically anisotropic layers 112 and 122 having the optical characteristics of the negative refractive index ellipsoid, and the liquid crystal display element 130 in the black display state as a whole is optically compensated three-dimensionally. Thus, light leakage can be prevented in a wide viewing angle.

(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 with light projected by the liquid crystal display device using a projection optical system. 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. 7 is an external view showing a rear type liquid crystal projector. As shown in FIG. 7, the liquid crystal projector 200 is provided with a diffusive 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 arranged inside a 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. 8 is a configuration diagram showing the projection unit 300. As shown in FIG. 8, the projection unit 300 includes three transmissive liquid crystal elements 311R, 311G, and 311B, and can project an image in full color.
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 from the light source 312 to the liquid crystal elements 311R, G, and B. The light enters the glass rod 314 according to the optical 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. Then, the light enters 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, and the polarizing plate on the incident surface side is a polarizer, and the polarized light on the outgoing surface side. The plate acts as an analyzer.
The liquid crystal display device of the present invention includes the liquid crystal elements 311R, 311G, 311B, polarizing plates 326R, 326G, 326B, 328R, 328G, 328B, and optical compensation elements 327R, 327G, 327B.
In addition, although the liquid crystal element provided for each color channel, the action of the polarizing plate and the optical compensation element respectively provided on both sides thereof are different based on each color light, the basic action is 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
[Production of optical compensation element]
An optical compensation element was produced by the following method.
-Alignment film-
On the glass substrate, 100 ml / m ² of an alignment film forming coating solution having the following composition is dropped and spin-coated under the condition of 1000 rpm. Thereafter, the alignment film-forming 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, rubbing treatment was performed on the formed alignment film to form an alignment film that is aligned in a predetermined alignment direction (hereinafter referred to as “lower alignment film”).
<Coating liquid for alignment film formation>
Modified polyvinyl alcohol of the following structural formula (3): 20 g
Water (solvent) ... 360g
Methanol ... 120g
Glutaraldehyde (crosslinking agent) ... 1.0g

-Organic layer-
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) , Manufactured by Eastman Chemical Co., Ltd.) 0.09 g, cellulose acetate butyrate (CAB531-1, manufactured by Eastman Chemical Co., Ltd.) 0.02 g, photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy Co.) 0.14 g, sensitizer (Kayacure DETX-S, manufactured by Nippon Kayaku Co., Ltd.) 0.05 g was dissolved in 12 g of ethyl 3-ethoxypropionate, 4 g of ethyl lactate and 4 g of 2- (1-methoxypropion) acetate, and a polymerizable liquid crystal compound was applied. A liquid was prepared.
The obtained polymerizable liquid crystal compound coating solution 100 ml / m ² is dropped onto the alignment film 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, UV irradiation was performed using a high-pressure mercury lamp at an irradiation energy of 300 mJ / cm ² to polymerize the polymerizable liquid crystal compound, thereby fixing the alignment state of the liquid crystal molecules. Then, it stood to cool to room temperature and formed the organic layer.

  In the formed organic layer, the discotic liquid crystal compound has an angle (orientation angle) between a normal axis of the disc surface and a normal of the glass substrate of 10 ° to 62 ° from the glass substrate side. It increased toward the air interface side, and the discotic liquid crystal compound was hybrid aligned. The orientation angle of the discotic liquid crystal compound is measured using an ellipsometer (M-150, manufactured by JASCO Corporation) to measure the retardation while changing the observation angle, and the refractive index ellipsoid model is obtained from the obtained measured values. Was calculated by the method described in “Design Concepts of the Discrete Negative Birefringence Compensation Films SID98 DIGEST”.

-Intermediate layer-
By using a sputtering apparatus on the formed organic layer, depositing Al ₂ O ₃ under reduced pressure, to form an intermediate layer. The thickness of the formed intermediate layer was 100 nm.

-Alignment film-
On this intermediate layer, the coating liquid for forming an alignment film composed of the modified polyvinyl alcohol is applied and rubbed in the same manner as described above, and the alignment film (hereinafter referred to as “alignment film”) , “The upper alignment film”).

-Organic layer-
On the obtained alignment film, an organic layer was formed in the same manner as the organic layer formed on the lower alignment film.
In the obtained organic layer, the discotic liquid crystal compound has an angle (orientation angle) between the vertical axis of the disc surface and the normal line of the glass substrate of 12 ° to 65 ° from the glass substrate side to the air interface side. The disk-like liquid crystal compound was hybrid aligned. Further, the obtained organic layer was a uniform film free from defects such as schlieren.

-Inorganic optical anisotropic layer-
On the obtained optically anisotropic layer, SiO ₂ and TiO ₂ are alternately deposited using a sputtering apparatus under reduced pressure to form a periodic structure laminate composed of a total of 52 layers each including 26 layers. did. The total thickness of the formed periodic structure laminate was 760 nm and Rth = 200 nm.

-Antireflection layer-
On the obtained inorganic optically anisotropic layer, SiO ₂ and TiO ₂ were alternately deposited using a sputtering apparatus under reduced pressure to form an antireflection layer. The formed antireflection layer had a thickness of 0.24 μm.

[Liquid Crystal Display]
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 ZnS was used for vapor deposition for forming the intermediate layer.

(Example 3)
A liquid crystal display device of Example 3 was obtained in the same manner as in Example 1 except that the alignment film forming coating solution composed of the following polyimide was used for the upper and lower alignment films.
[Coating liquid for forming alignment film]
Sun Ever 150 (Nissan Chemical Co., Ltd.) 20g
Thinner for polyimide (Nissan Chemical Co., Ltd.) ... 20g

Example 4
Implemented in the same manner as in Example 1 except that the alignment film forming coating solution composed of the polyimide was used for the upper and lower alignment films, and ZnS was used for vapor deposition for forming the intermediate layer. A liquid crystal display device of Example 4 was obtained.

(Example 5)
The same method as in Example 1 except that the alignment film forming coating solution composed of the polyimide was used for the upper alignment film and the alignment film forming coating solution composed of the polyvinyl alcohol was used for the lower alignment film. Thus, a liquid crystal display device of Example 5 was obtained.

(Comparative Example 1)
In the liquid crystal display device of Example 1, the liquid crystal display device of Comparative Example 1 was obtained in the same manner as in Example 1 except that the Al ₂ O ₃ layer as the intermediate layer was not formed on the optically anisotropic layer. It was.

(Comparative Example 2)
In the liquid crystal display device of Example 1, Example 1 was used except that the alignment film-forming coating solution composed of the polyimide was used for the alignment film and that no Al ₂ O ₃ layer was formed as an intermediate layer. In the same manner, a liquid crystal display device of Comparative Example 2 was obtained.

(Comparative Example 3)
In the liquid crystal display device of Example 1, the same as Example 1 except that the inorganic optically anisotropic layer was a TAC (triacetylcellulose) film and the Al ₂ O ₃ layer was not formed as an intermediate layer. Thus, a liquid crystal display device of Comparative Example 3 was obtained.

(Evaluation of proper application of organic layer)
About Examples 1-5 and Comparative Examples 1-3, after applying the coating liquid for alignment film formation on an organic layer and forming alignment film, the destruction condition of the surface of an organic layer is measured with the naked eye, and a result is obtained. It is shown in Table 1.

表１の結果から、前記有機層上へ配向膜を塗布した場合の前記有機層の破壊状況について、比較例２では、配向膜の形成にポリイミドで組成された配向膜形成用塗布液を用いており、該塗布液中の溶剤(ＮＭＰ: Ｎ−メチル−２−ピロリドン)が有機層に浸透し、前記有機層が破壊され、該表面に凹凸が発生していることが判る。これに対し、同じポリイミドで組成された配向膜形成用塗布液を用いている実施例３〜５では、既設の有機層と配向膜との間に無機材料を蒸着して中間層を形成したことにより、有機層への前記溶剤の浸透はなく、前記有機層は破壊されていないことが判る。
他方、比較例１及び３では、配向膜の形成に変性ポリビニルアルコールで組成された配向膜形成用塗布液を用いているため、前記有機層は破壊していないことが判る。
前記有機層の面状については、比較例１及び３は該有機層の表面にわずかな凹凸が生じ、比較例２では、著しい凹凸が生じているが、実施例１〜５では、いずれも前記表面は均一であり良好であることが判る。
前記配向膜形成用塗布液の塗布適正については、比較例１〜３では、ハジキ（有機層上に配向膜形成用塗布液を塗布する際に、該有機層の表面と該配向膜形成用塗布液との密着性に欠け、塗布液ののりがよくない状況をいう。）が多発しているのに対して実施例１〜５では、いずれもハジキは発生せず塗布適性は良好であることが判る。

From the results of Table 1, with respect to the destruction state of the organic layer when the alignment film is applied on the organic layer, in Comparative Example 2, the alignment film forming coating liquid composed of polyimide is used for forming the alignment film. It can be seen that the solvent (NMP: N-methyl-2-pyrrolidone) in the coating solution penetrates into the organic layer, the organic layer is destroyed, and irregularities are generated on the surface. On the other hand, in Examples 3 to 5 using the coating liquid for forming an alignment film composed of the same polyimide, an intermediate layer was formed by depositing an inorganic material between the existing organic layer and the alignment film. Thus, it can be seen that there is no penetration of the solvent into the organic layer, and the organic layer is not destroyed.
On the other hand, in Comparative Examples 1 and 3, it can be seen that the organic layer is not destroyed because the alignment film forming coating liquid composed of modified polyvinyl alcohol is used for forming the alignment film.
Regarding the surface shape of the organic layer, Comparative Examples 1 and 3 have slight unevenness on the surface of the organic layer, and Comparative Example 2 has remarkable unevenness. It can be seen that the surface is uniform and good.
As for the appropriateness of the coating liquid for forming the alignment film, in Comparative Examples 1 to 3, the surface of the organic layer and the coating for forming the alignment film are applied when recoating the alignment film forming coating liquid on the organic layer. In Examples 1-5, there is no occurrence of cissing, and coating suitability is good, while the adhesiveness with the liquid is poor and the coating liquid is not glued well. I understand.

(Evaluation of viewing angle dependence of liquid crystal display devices)
For the liquid crystal display devices of Examples 1 to 5 and Comparative Examples 1 and 3, the contrast was measured at a location with an elevation angle of 20 ° and an azimuth angle of 45 ° from the front of the display surface, using a conoscope (manufactured by Autronic-Melcher). . Since the surface of the said organic layer is destroyed, the comparative example 2 is excluded from the object of evaluation. Here, the contrast was measured as white display illuminance / black display illuminance from the white display illuminance and the black display illuminance with respect to the backlight, and the results are shown in Table 2.

(Evaluation of contrast of LCD projector)
Three liquid crystal display devices of Examples 1 to 5 and Comparative Examples 1 and 3 corresponding to each color of RGB are mounted on a TN type liquid crystal projector to obtain liquid crystal projectors of Examples 6 to 10 and Comparative Examples 4 and 6. It was. Comparative Example 5 corresponding to Comparative Example 2 is excluded from the evaluation because the surface of the organic layer is destroyed. About the obtained liquid crystal projector, the contrast (white display illuminance / black display illuminance) calculated from the white display illuminance, the black display illuminance on the screen installed at a distance of 3 m from the projection lens and the ratio thereof is measured. The results are shown in Table 2.

表２の結果から、比較例１及び３の液晶表示装置と比較して実施例１〜５の液晶表示装置は、いずれも広視野角であり、視野角依存性は同等であることが判る。また、実施例６〜１０の液晶プロジェクタは、比較例４及び５と比べていずれも同等以上のコントラストであることが判る。

From the results of Table 2, it can be seen that the liquid crystal display devices of Examples 1 to 5 have a wide viewing angle and the viewing angle dependency is the same as that of the liquid crystal display devices of Comparative Examples 1 and 3. It can also be seen that the liquid crystal projectors of Examples 6 to 10 have the same or higher contrast as compared with Comparative Examples 4 and 5.

  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 optical compensation element having a first structure. FIG. 2 is a cross-sectional view showing an optical compensation element having a second structure. FIG. 3 is a cross-sectional view showing an optical compensation element having a third structure. FIG. 4 is a cross-sectional view showing an optical compensation element having a fourth structure. FIG. 5 is a schematic view showing a liquid crystal display device of the present invention. FIG. 6 is a schematic view showing a liquid crystal display device of the present invention. FIG. 7 is an external view showing a rear type liquid crystal projector. FIG. 8 is a configuration diagram showing the projection unit.

Explanation of symbols

1, 21, 31, 41... Transparent support 2, 22, 32, 42, 112, 122 .. Inorganic optical anisotropic layer 3, 23, 33, 43, 113, 123 ..Organic layer 4, 24, 34, 44... Alignment film 5, 25, 35, 45... Antireflection layer 6, 26, 36, 46 ... Intermediate layer 10, 20, 30, 40 ... Optical compensation element 100 ... Liquid crystal Display device 200 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Liquid crystal projector 300 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Projection unit

Claims (23)

  An optically anisotropic layer characterized in that at least an alignment film and an intermediate layer are provided between organic layers formed of a polymerizable compound and exhibiting optical anisotropy.   The optically anisotropic layer according to claim 1, wherein the intermediate layer is formed of an inorganic material. The optically anisotropic layer according to claim 1, wherein the intermediate layer is an Al ₂ O ₃ layer and a ZnS layer formed by vapor deposition.   The optically anisotropic layer according to any one of claims 1 to 3, wherein the intermediate layer has a thickness of 5 to 5000 nm.   The organic layer is formed from a polymerizable liquid crystal compound containing a liquid crystal structure, and the orientation angle of the liquid crystal structure is fixed by polymerization in a state inclined with respect to the thickness direction of the organic layer. An optically anisotropic layer according to claim 1.   The optically anisotropic layer according to claim 5, wherein the liquid crystal structure in the organic layer has an orientation direction oriented in a certain direction.   The optically anisotropic layer according to claim 6, wherein the organic layer has two layers in which the orientation directions of at least two layers are different from each other.   The optically anisotropic layer according to claim 7, wherein two layers having different orientation directions of at least two layers in the organic layer are provided on one surface of the transparent support. One organic layer forming step of forming one organic layer exhibiting optical anisotropy on one alignment film;
An intermediate layer forming step of forming an intermediate layer on the organic layer;
An alignment film forming step of forming another alignment film on the intermediate layer;
Forming another organic layer exhibiting optical anisotropy on the other alignment film to form two or more organic layers; and
The manufacturing method of the optically anisotropic layer characterized by including.   The method for producing an optically anisotropic layer according to claim 9, wherein the intermediate layer is formed using an inorganic material. The method for producing an optically anisotropic layer according to claim 10, wherein Al ₂ O ₃ and ZnS or at least one of them is deposited to form an intermediate layer.   The method for producing an optically anisotropic layer according to claim 9, wherein an alignment film is formed by applying a coating liquid for forming an alignment film.   The method for producing an optically anisotropic layer according to claim 12, wherein the alignment film-forming coating solution contains N-methyl-2-pyrrolidone.   An optically anisotropic layer obtained by the production method according to claim 9.   An optical compensation element comprising both the optically anisotropic layer according to claim 1, the transparent support, and the inorganic optically anisotropic layer.   The optical compensation element according to claim 15, wherein the intermediate layer is located closer to the transparent support than the alignment film adjacent to the intermediate layer.   The optical compensation element according to any one of claims 15 to 16, comprising both an optically anisotropic layer and an inorganic optically anisotropic layer on at least one surface of the transparent support.   The inorganic 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 has a repeating structure, and the optical thickness of the repeating unit is in the visible light region. The optical compensation element according to claim 15, which is shorter than the wavelength of light and has negative refractive index anisotropy as a whole of the periodic structure.   The optical compensation element according to claim 18, wherein the periodic structure laminate is formed by alternately laminating two kinds of layers having different refractive indexes, and a difference in refractive index in the visible light region is 0.5 or more.   The optical compensation element according to claim 18, wherein the periodic structure laminate is an oxide layer.   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 15.   The liquid crystal display device according to claim 21, wherein the liquid crystal element is a twisted nematic type. 22. A liquid crystal display device that is 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. 23. A liquid crystal projector according to any one of items 1 to 22.

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