JP3452482B2 - Liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image of high quality which is free of coloration and has a wide field angle when a field angle is decreased or in the half-tone display by expanding the field angle in the right-left directions and top-bottom directions. SOLUTION: Between a liquid crystal display element 1 and polarizing plates 4 and 5, phase difference plates 2 and 3 are arranged which have a relation na=nc>nb between their main refractive indexes and also have the direction of the main refractive index nb slanted from the normal direction of the surface clockwise or counterclockwise around the direction of the main refractive index na nearly parallel to the surface as an axis and the direction of the main refractive index nc slanted from a direction nearly parallel to the surface. The liquid crystal layer 8 is so set that the combinational conditions of the degree of variation of the average alkyl chain length and ordinary light refractive index of the liquid crystal material with wavelength and the degree of variation of the extraordinary light refractive index with the wavelength are within a range wherein no screen coloration depending upon the field angle is produced. The liquid crystal layer 8 is divided into areas 8a and 8b having different alignment states in a pixel and those areas 8a and 8b are provided at different rates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device in which a viewing angle of a display screen is improved by combining a liquid crystal display element and a retardation element having optical anisotropy.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device using a nematic liquid crystal has been widely used as a numerical segment type display device such as a watch and a calculator. Furthermore, in recent years,
It is also widely used as a display device used in a word processor, a notebook personal computer, or the like, or a display device used in a navigation system or the like.

This liquid crystal display device generally has a pair of substrates which are opposed to each other with a liquid crystal layer interposed therebetween, and electrodes and wirings for turning on / off pixels are formed on the substrates. ing. For example, in an active matrix liquid crystal display device, pixel electrodes for applying a voltage to liquid crystal are provided in a matrix, and active elements such as field effect transistors are used as switching means for selectively applying a potential to each pixel electrode. Are provided on the substrate together with the electrodes and wiring. Furthermore, in a liquid crystal display device that performs color display, color filter layers of red, green, blue, etc. are provided on a substrate.

In such a liquid crystal display device, the following display methods are known depending on the twist angle of the nematic liquid crystal used.

(1) An active drive type twisted nematic liquid crystal display system (hereinafter referred to as TN system) in which the twist angle of nematic liquid crystal molecules is twisted and aligned between the pair of substrates at 90 °.

(2) A multiplex drive type super twist nematic liquid crystal display system (hereinafter referred to as STN system) in which a twist angle of nematic liquid crystal molecules is twisted and aligned between a pair of substrates by more than 90 °.

By the way, in the liquid crystal display device of the above display system, there is a wide viewing angle dependency that the contrast of the displayed image changes or the reversal phenomenon occurs depending on the direction and the viewing angle of the viewer. There is a problem that the viewing angle characteristic of the visual field cannot be obtained.

In order to solve this problem, for example, Japanese Patent Application Laid-Open No. 57-1867835 discloses an alignment division method for dividing the alignment of the liquid crystal layer so that a plurality of viewing angle characteristics occur in each pixel. Alternatively, JP-A-7-234407
Japanese Patent Laid-Open No. 7-248497 and Japanese Patent Laid-Open No. 7-248497 disclose a method of causing a plurality of twist alignments in liquid crystal in each pixel.

However, when the pixel is divided into two by such a pixel division method and two regions having different alignment states are formed in the pixel, the vertical direction of the display screen (12 o'clock to 6 o'clock direction).
And the left-right direction (3 o'clock-9 o'clock direction) have completely different viewing angle characteristics. For example, if the viewing angle is tilted in the vertical direction, the light transmittance during black display increases and the contrast becomes insufficient. In the horizontal direction, the contrast is good but the reversal phenomenon occurs.

Further, when a plurality of twist orientations are generated in each pixel or a plurality of orientations are divided, it is difficult to improve the viewing angle characteristics in the azimuth 45 ° direction from the absorption axis or the transmission axis of the polarizing plate.

Therefore, Japanese Unexamined Patent Publication No. 6-118406 and Japanese Unexamined Patent Publication No. 6-194645 disclose a technique in which the above-mentioned pixel division method and an optical retardation plate are combined.

First, in Japanese Unexamined Patent Publication No. 6-118406, a liquid crystal whose contrast is improved by inserting a film (optical retardation plate) having optical anisotropy between a liquid crystal display element and a polarizing plate. A display device is disclosed.

Next, in JP-A-6-194645, there is almost no refractive index in the plane parallel to the surface of the compensating plate (optical retardation plate), and refraction in the direction perpendicular to the surface of the compensating plate. A compensating plate is disclosed in which the index is set to be smaller than the in-plane refractive index. Since such a compensator has a negative refractive index anisotropy, it is possible to reduce the viewing angle dependency by compensating for the positive refractive index anisotropy that occurs in the liquid crystal display element when a voltage is applied.

However, in a situation where a liquid crystal display device having a wider viewing angle and a higher display quality is desired as in today's day, the pixel division method as described above is combined with a negative uniaxial optical retardation plate. Playing alone is not enough. The reason is that in the above-mentioned technique, since the pixel division ratio is the same, it is possible to improve the horizontal direction by using the negative uniaxial optical retardation plate, but the vertical direction is the same as the conventional TN-LCD.
This is because the 6 o'clock direction and the 12 o'clock direction in the (twisted nematic liquid crystal display) are superposed, and therefore it is not so much improved only by using the negative uniaxial optical retardation plate.

Therefore, Japanese Patent Laid-Open No. 10-3081 discloses a technique of combining a pixel division method for dividing the inside of a pixel at different ratios with the above-described optical retardation plate having a tilted index ellipsoid. ing. In the liquid crystal display device disclosed in this publication, the tilt direction of the refractive index ellipsoid of the optical retardation plate and the pretilt direction of the liquid crystal molecules near the alignment film are opposite to each other in a large divided area in each pixel. The liquid crystal display element and the optical retardation plate are arranged so that As a result, it is possible to increase the viewing angle in the horizontal direction and simultaneously increase the viewing angle in the vertical direction.

[0016]

However, under the circumstances where a liquid crystal display device having a wider viewing angle, a higher display quality and excellent color reproducibility is required as in today's environment,
It is not always sufficient to simply combine the pixel division method of dividing pixels at different ratios as described above and the optical retardation plate having the inclined ellipsoid.

For example, when the optical retardation plate (optical anisotropic film) as described above is arranged between the polarizing plate and the liquid crystal display element, the wavelength dependence of the normal light refractive index of the liquid crystal material and the extraordinary light refraction If the wavelength dependence of the refractive index and the refractive index of the optical retardation plate do not match well, there is a problem that the color of the displayed image becomes noticeable when the viewing angle is tilted or halftone is displayed, and the state of the displayed image deteriorates significantly. .

The present invention has been made to solve the above problems of the prior art, and it is possible to expand the viewing angle in the vertical direction at the same time as the horizontal direction. Further, when the viewing angle is tilted or halftone is applied. An object of the present invention is to provide a liquid crystal display device capable of realizing high-quality image display with a wide viewing angle in which coloring is not generated during display.

[0019]

A liquid crystal display device according to the present invention is a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates, and an alignment film is provided on the liquid crystal layer side surface of at least one of the substrates. And a pair of polarizers sandwiching both sides of the liquid crystal display element, and at least one polarizer and at least one optical retardation element provided between the liquid crystal display elements, each of the liquid crystal layers In a liquid crystal display device in which a liquid crystal is divided into a plurality of regions in which the alignment state of liquid crystal is different, and the ratio of each region occupied in the pixel is different, the three main refractive indices na of the refractive index ellipsoid of the optical retardation element are , Nb and nc are na
= Nc> nb, and the direction of the main refractive index nb is tilted clockwise or counterclockwise from the normal direction of the surface with the main refractive index na substantially parallel to the surface of the optical retardation element as an axis. In addition, the direction of the main refractive index nc is inclined clockwise or counterclockwise from the direction substantially parallel to the surface, and
The combination conditions of the average alkyl chain length of the liquid crystal material in the liquid crystal layer, the degree of change of the normal light refractive index no of the liquid crystal material with respect to the wavelength, and the degree of change of the extraordinary light refractive index ne of the liquid crystal material with respect to the wavelength are viewing angles. Is set in a range in which the screen coloring depending on is not generated, and thereby the above object is achieved.

The average alkyl chain (C _m H
The length m of _{2m + 1} −) is set in the range of m> 3.90, and the extraordinary refractive index n of the liquid crystal material with respect to light having a wavelength of 450 nm is n.
e (450), extraordinary light refractive index ne (550) for light of wavelength 550 nm and extraordinary light refractive index ne (650) for light of wavelength 650 nm, and normal light refractive index no (450) for light of wavelength 450 nm, wavelength 550 nm Refractive index no (550) and wavelength 650nm for light
The normal light refractive index no (650) for the light is −0.422m + 2.55 ≦ ((no (450) −no
(550)) / (no (550) -no (650)))
/ ((Ne (450) -ne (550)) / (ne (5
50) -ne (650))) ≦ 1.00 may be set.

Extraordinary light refractive index ne (450) for light of wavelength 450 nm, extraordinary light refractive index ne (550) for light of wavelength 550 nm and wavelength 650 nm of the liquid crystal material
The extraordinary refractive index ne (650) for the light of
Normal light refractive index no (450) for light of 0 nm, normal light refractive index no (550) for light of wavelength 550 nm, and normal light refractive index no (65 for light of wavelength 650 nm)
0) and −0.343m + 2.26 ≦ ((no (450) −no
(550)) / (no (550) -no (650)))
/ ((Ne (450) -ne (550)) / (ne (5
50) -ne (650))) ≦ 1.00 may be set.

The average alkyl chain (C _m H
The length m of _{2m + 1} −) is set in the range of m <3.40, and the extraordinary refractive index n of the liquid crystal material with respect to light having a wavelength of 450 nm is n.
e (450), extraordinary light refractive index ne (550) for light of wavelength 550 nm and extraordinary light refractive index ne (650) for light of wavelength 650 nm, and normal light refractive index no (450) for light of wavelength 450 nm, wavelength 550 nm Refractive index no (550) and wavelength 650nm for light
The normal light refractive index no (650) for the light is 1.00 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ −0.422 m + 2.55.

Extraordinary light refractive index ne (450) for light of wavelength 450 nm, extraordinary light refractive index ne (550) for light of wavelength 550 nm and wavelength 650 nm of the liquid crystal material
The extraordinary refractive index ne (650) for the light of
Normal light refractive index no (450) for light of 0 nm, normal light refractive index no (550) for light of wavelength 550 nm, and normal light refractive index no (65 for light of wavelength 650 nm)
0) and 1.00 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ −0.343 m + 2.26 may be set.

The average alkyl chain (C _m H
The length m of _{2m + 1} −) is set in the range of 3.40 ≦ m ≦ 3.90, and the extraordinary light refractive index ne (450) of the liquid crystal material with respect to light having a wavelength of 450 nm and the extraordinary light with respect to light of 550 nm are given. Refractive index ne (550) and extraordinary refractive index ne (650) for light with wavelength 650 nm and wavelength 450 nm
Refractive index for normal light no (450), wavelength 550
The normal light refractive index no (550) for light of wavelength nm and the normal light refractive index no (650) for light of wavelength 650 nm are 0.80 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ 1.20.

Extraordinary light refractive index ne (450) for light of wavelength 450 nm, extraordinary light refractive index ne (550) for light of wavelength 550 nm and wavelength 650 nm of the liquid crystal material
The extraordinary refractive index ne (650) for the light of
Normal light refractive index no (450) for light of 0 nm, normal light refractive index no (550) for light of wavelength 550 nm, and normal light refractive index no (65 for light of wavelength 650 nm)
0) and 0.85 <((no (450) -no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) <1.15 may be set.

The refractive index anisotropy Δn (550) of the liquid crystal material with respect to light having a wavelength of 550 nm is preferably set in the range of 0.060 <Δn (550) <0.120.

The refractive index anisotropy Δn (550) of the liquid crystal material with respect to light having a wavelength of 550 nm is preferably set in the range of 0.070 ≦ Δn (550) ≦ 0.095.

The tilt angle of the refractive index ellipsoid in the optical retardation element is preferably set in the range of 15 ° or more and 75 ° or less.

The main refractive indices na and n of the optical retardation element
The product of the difference in b and the thickness d of the optical retardation element (na-n
It is preferable that b) × d is set in the range of 80 nm to 250 nm.

Among the plurality of regions having different alignment states of the liquid crystal, in the largest region in the pixel, the alignment treatment direction of the alignment film and the main refractive indices nb and n of the optical retardation element.
It is preferable that the liquid crystal display element and the optical retardation element are arranged so that the inclination direction of c is opposite to the inclination direction.

In the smallest region in the pixel among the plurality of regions having different alignment states of the liquid crystal, the alignment treatment direction of the alignment film and the inclination directions of the main refractive indices nb and nc of the optical retardation element are the same. It is preferable that the liquid crystal display element and the optical retardation element are arranged so as to be oriented.

The liquid crystal layer is divided into two regions in each pixel, and the ratio of the first region and the second region in each pixel is 6: 4.
It is preferable that the range is set to 19: 1 or less.

The background of the completion of the present invention and the operation of the present invention will be described below.

As described above, the liquid crystal display device in which the liquid crystal layer is divided into a plurality of regions having different ratios in each pixel at different ratios, and the optical phase difference having a negative uniaxial property in which the refractive index ellipsoid is inclined. By combining with the element, the left-right direction (3
It is possible to increase the viewing angle in the vertical direction (6 o'clock to 12 o'clock direction) at the same time as expanding the viewing angle in the 9 o'clock to 9 o'clock direction.

In this liquid crystal display device, the liquid crystal display element and the optical element are optically arranged so that the direction in which the liquid crystal molecules rise in the largest area in the pixel when the voltage is applied is opposite to the tilt direction of the refractive index ellipsoid of the optical retardation element. When the retardation element is arranged, the refractive index anisotropy of the liquid crystal molecules rising with the voltage application in the largest area in the pixel is compensated by the optical retardation element having negative uniaxiality. In this case, the contrast can be improved and the gradation inversion can be reduced, but on the other hand, there is a problem that the black gradation is crushed. Therefore, in the smallest area in the pixel, the liquid crystal molecules are arranged so that the rising direction thereof when the voltage is applied is the same as the tilt direction of the refractive index ellipsoid of the optical phase difference element. In this case, since the minimum area has a viewing angle characteristic opposite to that of the maximum area, the addition of this component can reduce the collapse of the black gradation in the maximum area and increase the vertical viewing angle.

However, also in such a liquid crystal display device, the wavelength dependence of the normal light refractive index no of the liquid crystal material, the wavelength dependence of the extraordinary light refractive index ne of the liquid crystal material, and the wavelength dependence of the refractive index of the optical phase difference plate. If the matching with the sex is poor, the display screen is markedly colored when the viewing angle is tilted or halftone is displayed, and the state of the displayed image is significantly deteriorated.

Therefore, in the present invention, a high-quality liquid crystal display device having a wide viewing angle in the horizontal direction as well as the vertical direction and a high viewing angle in which coloring is not generated when the viewing angle is tilted or halftone is displayed is realized. In order to do so, design guidelines for the material of the liquid crystal layer were set.

In the liquid crystal display device of the present invention, the average alkyl chain length of the liquid crystal material and the normal light refractive index no of the liquid crystal material are
The combination condition of the degree of change with respect to the wavelength and the extraordinary light refractive index ne is set to a range in which screen coloring depending on the viewing angle does not occur. This makes it possible to further prevent the screen from being colored, and further, as shown in the embodiments described later, it is possible to further improve the contrast change and the inversion phenomenon as compared with the case where only the compensation function of the retardation film is used. it can.

Specifically, the combination conditions of the average alkyl chain length of the liquid crystal material, the degree of change of the normal light refractive index no of the liquid crystal material with respect to the wavelength, and the degree of change of the extraordinary light refractive index ne of the liquid crystal material with respect to the wavelength are: , Set as follows.

(1) Average alkyl chain of liquid crystal material (C _m H
_When the length m of _{2m + 1} −) is m> 3.90, the extraordinary light refractive index ne (45
0), the extraordinary refractive index ne for the light of wavelength 550 nm
(550) and an extraordinary light refractive index ne (650) for light having a wavelength of 650 nm, a normal light refractive index no (450) for light having a wavelength of 450 nm, a normal light refractive index no (550) for light having a wavelength of 550 nm, and a wavelength of 650 nm. The normal light refractive index no (650) for light is −0.422 m + 2.55 ≦ ((no (450) −no
(550)) / (no (550) -no (650)))
/ ((Ne (450) -ne (550)) / (ne (5
50) -ne (650))) ≦ 1.00.

Within this range, a high-quality display image can be obtained at a wide viewing angle without coloring when the viewing angle is tilted or halftone is displayed, as shown in Embodiment 1 described later.

More preferably, -0.343m + 2.26≤ ((no (450) -no
(550)) / (no (550) -no (650)))
/ ((Ne (450) -ne (550)) / (ne (5
50) -ne (650))) ≦ 1.00.

Within this range, as shown in Embodiment 1 to be described later, it is possible to obtain a display image in which the coloring is further eliminated, the viewing angle is wide, the quality is high, and the color reproducibility is excellent.

(2) Average alkyl chain (C _m H of liquid crystal material)
_When the length m of _{2m + 1} −) is m <3.40, the extraordinary light refractive index ne (45
0), the extraordinary refractive index ne for the light of wavelength 550 nm
(550) and an extraordinary light refractive index ne (650) for light having a wavelength of 650 nm, a normal light refractive index no (450) for light having a wavelength of 450 nm, a normal light refractive index no (550) for light having a wavelength of 550 nm, and a wavelength of 650 nm. The normal light refractive index no (650) for light is expressed as 1.00 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ −0.422 m + 2.55.

Within this range, a high-quality display image can be obtained at a wide viewing angle without coloring when the viewing angle is tilted or halftone is displayed, as shown in Embodiment 2 described later.

More preferably, 1.00≤ ((no (450) -no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ −0.343m + 2.26.

Within this range, as will be described in the second embodiment, it is possible to obtain a display image in which the coloring is further eliminated, the viewing angle is wide, the quality is high, and the color reproducibility is excellent.

(3) Average alkyl chain (C _m H of liquid crystal material)
_When the length m of _{2m + 1} −) is 3.40 ≦ m ≦ 3.90, the extraordinary refractive index ne (450) of the liquid crystal material with respect to light having a wavelength of 450 nm and the extraordinary refractive index ne of light with a wavelength of 550 nm are shown. (550) and the extraordinary light refractive index ne (650) for light of wavelength 650 nm, the normal light refractive index no (450) for light of wavelength 450 nm, the normal light refractive index no (550) and wavelength 650 for light of wavelength 550 nm.
The normal light refractive index no (650) for the light of nm is 0.80 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ 1.20.

Within this range, a high-quality display image can be obtained with a wide viewing angle without coloring when the viewing angle is tilted or halftone is displayed, as shown in Embodiment 3 described later.

More preferably, 0.85 <((no (450) -no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) <1.15.

Within this range, as will be described in the third embodiment, a display image having a wide viewing angle, high quality, and excellent color reproducibility can be obtained without coloring.

The liquid crystal display device of the present invention has a wavelength of 5
Refractive index anisotropy Δn (5
50) is preferably set in the range of 0.060 <Δn (550) <0.120. Refractive index anisotropy Δn of the liquid crystal material with respect to light having a wavelength of 550 nm in the visible light region
This is because, when (550) is 0.060 or less or 0.120 or more, it has been confirmed that an inversion phenomenon and a decrease in contrast ratio occur depending on the viewing angle direction, as shown in Embodiment 4 described later. Therefore, by setting the refractive index anisotropy Δn (550) of the liquid crystal material with respect to light having a wavelength of 550 nm in a range of more than 0.060 and less than 0.120, it is possible to eliminate the phase difference according to the viewing angle. It is possible to further improve the change in contrast and the inversion phenomenon in the horizontal direction on the liquid crystal display screen.

Further, by setting the refractive index anisotropy Δn (550) of the liquid crystal material with respect to light having a wavelength of 550 nm in the range of 0.070 ≦ Δn (550) ≦ 0.095, a fourth embodiment will be described later. As described above, it is possible to more effectively and surely eliminate the phase difference that occurs in the liquid crystal display element depending on the viewing angle. Therefore,
It is possible to surely improve the contrast change and the inversion phenomenon in the horizontal direction on the liquid crystal display screen.

In the liquid crystal display device of the present invention, the tilt angle of the refractive index ellipsoid in the optical retardation element is 15 ° or more and 7 ° or more.
It is preferably set in the range of 5 ° or less. By setting the tilt angle of the refractive index ellipsoid in this way, it is possible to reliably obtain the compensation function of the optical phase difference element, as described in Embodiment 4 below.

In the liquid crystal display device of the present invention, the product (na−nb) × d of the difference between the main refractive indices na and nb of the optical retardation element and the thickness d is in the range of 80 nm to 250 nm. It is preferable to set. By setting the product of the difference between the main refractive indices na and nb of the optical retardation element and the thickness d in this manner, the compensation function of the optical retardation element is surely obtained, as described in Embodiment 4 below. be able to.

In the liquid crystal display device of the present invention, the alignment treatment direction (rubbing direction) of the alignment film and the main of the optical retardation element are the largest in the pixel among the plurality of regions in which the alignment state of the liquid crystal is different. It is preferable that the refractive indexes nb and nc are arranged so as to be in opposite directions to each other. With this arrangement, the rising direction of the liquid crystal molecules when a voltage is applied and the tilting direction of the refractive index ellipsoid of the optical phase difference plate are opposite to each other, so that the optical anisotropy associated with the rising of the liquid crystal molecules is prevented. The optical retardation plate can surely compensate.

Further, in the smallest region in the pixel, the alignment treatment direction of the alignment film and the main refractive indices nb and n of the optical retardation element are set.
It is preferable to arrange the liquid crystal display element and the optical retardation element so that the inclination direction of c is the same direction. in this case,
The smallest area in a pixel has a viewing angle characteristic opposite to that of the largest area in a pixel. Therefore, by adding this component, it is possible to reduce the collapse of black gradation in the largest area and increase the vertical viewing angle. You can

When the liquid crystal layer is divided into two regions in each pixel, the ratio of the first region and the second region in each pixel is set within the range of 6: 4 or more and 19: 1 or less. Is preferred. By setting this range, the contrast in the vertical direction and the black reversal are reduced, and the collapse of the black gradation is reduced to increase the viewing angle in the vertical direction, as shown in Embodiment 5 described later. You can

[0059]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the structure of a liquid crystal display device according to an embodiment of the present invention. The liquid crystal display device includes a unit (liquid crystal cell 16) including a liquid crystal display element 1, a pair of optical retardation plates 2 and 3, and a pair of polarizing plates (polarizers) 4 and 5, and a drive circuit 17. .

The liquid crystal display element 1 has a structure in which a liquid crystal layer 8 is sandwiched between a pair of electrode substrates 6 and 7 arranged so as to face each other. In one electrode substrate 6, a transparent electrode 10 made of ITO (indium tin oxide) is formed on the surface of a glass substrate (translucent substrate) 9 serving as a base on the liquid crystal layer 8 side, and an alignment film 11 is formed thereon. Has been formed. The other electrode substrate 7
The transparent electrode 13 made of ITO is formed on the surface of the base glass substrate (translucent substrate) 12 on the liquid crystal layer 8 side, and the alignment film 14 is formed thereon. Both transparent electrodes 10 and 11 are connected to a drive circuit 17.

Incidentally, in FIG.
Although the configuration for a pixel is shown, almost all of the display portion of the liquid crystal display element 1 is a strip-shaped transparent electrode 10, 13 having a predetermined width.
Are provided on the glass substrates 9 and 12 at predetermined intervals,
The transparent electrode 10 on one glass substrate 9 and the transparent electrode 13 on the other glass substrate 10 are formed so as to intersect (here, orthogonal to each other) when viewed from a direction perpendicular to the substrate surface.

The intersection of the transparent electrodes 10 and 13 corresponds to a pixel for displaying, and these pixels are arranged in a matrix on the entire surface of the liquid crystal display device.

Both electrode substrates 6 and 7 are bonded together by a seal resin 15, and the electrode substrates 6 and 7 and the seal resin 1 are bonded together.
A liquid crystal layer 8 is enclosed in a space surrounded by 5. A voltage based on display data is applied to the liquid crystal layer 8 from the drive circuit 17 via the transparent electrodes 10 and 13.

The alignment films 11 and 14 provided on the surfaces of both electrode substrates 6 and 7 on the liquid crystal layer 8 side have two regions having different states from each other, and a pretilt for imparting liquid crystal molecules between the two regions. The angles are made different, and the pretilt directions of the liquid crystal molecules are made opposite to each other with respect to the direction perpendicular to the substrate surface. Thus, in the liquid crystal layer 8, the first region 8a facing one region of the alignment film and the second region 8b facing the other region are controlled so that the alignment state of the liquid crystal molecules is different.

Further, in this embodiment, in order to improve the viewing angle characteristics when the viewing angle is tilted in the vertical direction and the horizontal direction, as shown in FIG. 2, the alignment state of the liquid crystal layer 8 is different in one pixel. The regions 8a and 8b are divided at different ratios.

FIG. 2 is a schematic diagram when the liquid crystal panel is viewed from the normal direction, and an arrow P1 indicates the alignment film 1 in the region 8a.
The rubbing direction on the 1st side, the arrow P3 indicates the rubbing direction on the alignment film 14 side in the region 8a, the arrow P2 indicates the rubbing direction on the alignment film 11 side in the region 8b, and the arrow P4 indicates the region 8.
The rubbing direction on the alignment film 14 side in b is shown. By thus subjecting the alignment films 11 and 14 to the rubbing treatment, the inside of the pixel can be divided into liquid crystal regions 8a and 8b having different alignment states at different ratios.

The liquid crystal display element 1 and the polarizing plates 4 and 5 on both sides thereof.
One optical retardation plate 2 and one optical retardation plate 3 are disposed between and. The optical retardation plates 2 and 3 are obtained by cross-linking discotic liquid crystals in a tilted or hybrid orientation on a support made of a transparent organic polymer. Thereby, as will be described later, the retardation plates 2 and 3 in which the refractive index ellipsoids are inclined are obtained.

Triacetyl cellulose (TAC), which is generally used as a material for polarizing plates, is most suitable as the support material for the optical retardation plates 2 and 3, and a highly reliable retardation plate can be obtained. Other materials include polycarbonate (PC), polyethylene terephthalate (P
A colorless and transparent organic polymer film having excellent environmental resistance and chemical resistance such as ET) is suitable.

As shown in FIG. 3, the optical retardation plates 2 and 3 have different main refractive indices na, nb and nc in three directions.

The direction of the main refractive index na coincides with the direction of the y-axis which is parallel to the surfaces of the phase difference plates 2 and 3 (parallel to the screen) of the coordinate axes xyz orthogonal to each other. The direction of the main refractive index nb is the phase difference plate 2 with the direction of the main refractive index na as the axis.
3 inclines in the direction of arrow A from the direction of the z-axis that is perpendicular to the surface (the normal direction of the surface, perpendicular to the screen). Principal refractive index nc
The direction of is tilted in the direction of arrow B from the direction of the x-axis parallel to the surfaces of the phase difference plates 2 and 3 (parallel to the screen) about the direction of the main refractive index na. In FIG. 3, the main refractive index nb that is inclined in a direction that gives anisotropy to the retardation plates 2 and 3.
The direction in which the direction is projected onto the surfaces of the phase difference plates 2 and 3 is D.

The three main refractive indices na, nb and nc are na
= Nc> nb. In this case, since there is only one optical axis, the optical retardation plates 2 and 3 have uniaxiality, and the refractive index anisotropy is negative.

The first retardation value of the optical retardation plates 2 and 3 is the product of the difference between the main refractive indices na and nc (refractive index anisotropy Δn) and the thickness d of the optical retardation plate (nc- na) ×
Although it is represented by d, it is almost 0 nm because na = nc. The second retardation value is the main refractive index na and nb.
The difference (refractive index anisotropy Δn) and the thickness d of the optical retardation plate is represented by (na−nb) × d.
It is preferably set in the range of 0 nm or less. By setting this range, it is possible to surely obtain the phase difference compensation function by the optical phase difference plates 2 and 3.

In the liquid crystal display device of this embodiment, the liquid crystal display element 1, the phase difference plates 2 and 3, and the polarizing plates 4 and 5 are the same as those shown in FIG.
It is arranged as shown in. In addition, in this figure,
The region 8b is omitted for simplicity.

The absorption axis AX1 of the polarizing plate 4 is the above-mentioned region 8a.
Are arranged so as to be parallel to the rubbing direction P1 on the side of the alignment film 11 and the absorption axis AX2 of the polarizing plate 5 is arranged to be parallel to the rubbing direction P3 on the side of the alignment film 14 in the region 8a. The optical retardation plate 2 is arranged so that the direction D (D1) shown in FIG. 3 is parallel to the rubbing direction P1 on the alignment film 11 side in the region 8a, and the optical retardation plate 3 is shown in FIG. Direction D (D2) is area 8a
Are arranged so as to be parallel to the rubbing direction P3 on the alignment film 14 side in FIG.

Further, in the above-mentioned liquid crystal layer 8, the average alkyl chain length of the liquid crystal material and the normal light refraction of the liquid crystal material are considered in consideration of the matching with the wavelength dependence of the refractive index of the optical retardation plates 2 and 3. The combination condition of the degree of change of the index no with respect to the wavelength and the degree of change of the extraordinary refractive index ne of the liquid crystal material with respect to the wavelength is set in a range in which coloring depending on the viewing angle does not occur on the display screen.

Specifically, the combination conditions of the average alkyl chain length of the liquid crystal material, the degree of change of the normal light refractive index no of the liquid crystal material with respect to the wavelength, and the degree of change of the extraordinary light refractive index ne of the liquid crystal material with respect to the wavelength are: , (1) to (3) shown below
Set to satisfy either condition of.

(1) Average alkyl chain (C _m H of liquid crystal material)
_When the length m of _{2m + 1} −) is m> 3.90, the extraordinary light refractive index ne (45
0), the extraordinary refractive index ne for the light of wavelength 550 nm
(550) and an extraordinary light refractive index ne (650) for light having a wavelength of 650 nm, a normal light refractive index no (450) for light having a wavelength of 450 nm, a normal light refractive index no (550) for light having a wavelength of 550 nm, and a wavelength of 650 nm. The normal light refractive index no (650) for light is −0.422 m + 2.55 ≦ ((no (450) −no
(550)) / (no (550) -no (650)))
/ ((Ne (450) -ne (550)) / (ne (5
50) -ne (650))) ≦ 1.00.

More preferably, -0.343m + 2.26≤ ((no (450) -no
(550)) / (no (550) -no (650)))
/ ((Ne (450) -ne (550)) / (ne (5
50) -ne (650))) ≦ 1.00.

(2) Average alkyl chain (C _m H of liquid crystal material)
_When the length m of _{2m + 1} −) is m <3.40, the extraordinary light refractive index ne (45
0), the extraordinary refractive index ne for the light of wavelength 550 nm
(550) and an extraordinary light refractive index ne (650) for light having a wavelength of 650 nm, a normal light refractive index no (450) for light having a wavelength of 450 nm, a normal light refractive index no (550) for light having a wavelength of 550 nm, and a wavelength of 650 nm. The normal light refractive index no (650) for light is expressed as 1.00 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ −0.422 m + 2.55.

More preferably, 1.00≤ ((no (450) -no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ −0.343m + 2.26.

(3) Average alkyl chain (C _m H of liquid crystal material)
_When the length m of _{2m + 1} −) is 3.40 ≦ m ≦ 3.90, the extraordinary refractive index ne (450) of the liquid crystal material with respect to light having a wavelength of 450 nm and the extraordinary refractive index ne of light with a wavelength of 550 nm are shown. (550) and the extraordinary light refractive index ne (650) for light of wavelength 650 nm, the normal light refractive index no (450) for light of wavelength 450 nm, the normal light refractive index no (550) and wavelength 650 for light of wavelength 550 nm.
The normal light refractive index no (650) for the light of nm is 0.80 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ 1.20.

More preferably, 0.85 <((no (450) -no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) <1.15.

With this configuration, the liquid crystal display device of this embodiment can obtain a high-quality display image with a wide viewing angle without coloring when the viewing angle is tilted or halftone is displayed.

The liquid crystal display device of the present invention will be described below.
A more specific embodiment will be described.

(Embodiment 1) In Embodiment 1, in the liquid crystal display device shown in FIG. 1, a material system represented by the following structural formula is blended as a liquid crystal material of the liquid crystal layer 8 to obtain an average alkyl chain for 1 mol. The length _{m of} (C _m H _{2m + 1} −) is m
> 3.90, the extraordinary refractive index ne (450) for the light of the wavelength of 450 nm, the extraordinary refractive index ne (550) for the light of the wavelength of 550 nm, and the wavelength of 650 nm of the liquid crystal material.
Of the extraordinary light refractive index ne (650) with respect to the light of
50), the normal light refractive index no for light with a wavelength of 550 nm
(550) and the degree of change of the normal light refractive index no (650) with respect to light having a wavelength of 650 nm are −0.422 m + 2.55 ≦ ((no (450) −no (550)) / (no (550) −no ( 650))) / ((ne (450) -ne (550)) / (ne (550) -ne (650))) ≦ 1.00 (A).

[0087]

[Chemical 1]

Optomer AL (trade name) manufactured by Japan Synthetic Rubber Co., Ltd. is used as the alignment films 11 and 14, and the first region 8a and the second region 8b of the liquid crystal layer 8 are set to 17: 3, and the liquid crystal cell 16 is formed. The cell thickness (thickness of the liquid crystal layer 8) was 5 μm, and the five liquid crystal display devices (Sample # 1) shown in Table 1 below were used.
1 to # 15) were produced. In addition, in the following Table 1 and Tables 3, 5, 7, and 8 of Embodiments 2 to 5 described later, F {no (λ), ne (λ)} = ((no (450)-
no (550)) / (no (550) -no (65
0))) / ((ne (450) -ne (550)) /
(Ne (550) -ne (650))) is shown.

[0089]

[Table 1]

As the optical retardation plates 2 and 3, a discotic liquid crystal is applied to a transparent support (eg, triacetyl cellulose (TAC)), and the discotic liquid crystal is obliquely aligned and crosslinked to form a first optical disc. The retardation value (nc-na) × d is 0 nm, the second retardation value (na-nb) × d is 100 nm, and the direction of the main refractive index nb shown in FIG. 3 is from the z-axis direction in the xyz coordinate axes. An index ellipsoid having an inclination angle θ = 20 ° in which the direction of the main refractive index nc was inclined by about 20 ° in the direction of arrow A and the direction of the main refractive index nc was inclined by about 20 ° in the direction of arrow B from the x-axis direction was produced.

Further, for comparison, in the liquid crystal display device shown in the liquid crystal display device of FIG. 1, as the liquid crystal material of the liquid crystal layer 8, F {no (λ), ne (λ)} is the above formula (A).
The two liquid crystal display devices (Comparative Samples # 201 and # 202) shown in Table 1 above were produced in the same manner as this embodiment except that the liquid crystal material out of the range was used.

Table 2 below shows the results of visual evaluation of the tint of the samples # 11 to # 15 and the comparative samples # 201 and # 202 at visual angles of 50 °, 60 ° and 70 °. In addition, Table 2 below and Embodiments 2 and 3 described later.
In Tables 4 and 6, ◯ indicates that there is no coloration, Δ indicates that the coloration is durable enough to be used, and x indicates that the coloration is unusable.

[0093]

[Table 2]

As shown in Table 2 above, the samples # 13 to # 15 of this embodiment did not show any coloring even when tilted to a viewing angle of 70 °, and the display characteristics were very good. Therefore, −0.343m + 2.26 ≦ ((no (450) −no
(550)) / (no (550) -no (650)))
/ ((Ne (450) -ne (550)) / (ne (5
It is understood that more excellent characteristics can be obtained in the range of 50) -ne (650))) ≦ 1.00.

In addition, samples # 11 and # of this embodiment are
With respect to No. 12, coloring was observed at a viewing angle of 60 ° and 70 °, but no coloring was observed up to a viewing angle of 50 °, and the display characteristics were good and it was a level that could be used.

On the other hand, in Comparative Samples # 201 and # 202, coloring was severe when tilted to a viewing angle of 50 °, and it was not a level that could be used.

(Embodiment 2) In the embodiment 2, in the liquid crystal display device shown in FIG. 1, the material system shown in the embodiment 2 is blended as the liquid crystal material of the liquid crystal layer 8 to obtain an average alkyl chain for 1 mol. Let the length _{m of} (C _m H _{2m + 1} −) be m <
3.40, the extraordinary refractive index ne (450) for the light of wavelength 450 nm, the extraordinary refractive index ne (550) for the light of wavelength 550 nm, and the extraordinary refractive index ne (650) for the light of wavelength 650 nm. The degree of change,
Normal light refractive index no (45
0), normal light refractive index no for light with a wavelength of 550 nm
(550) and the degree of change of the normal light refractive index no (650) with respect to light having a wavelength of 650 nm are expressed as 1.00 ≦ ((no (450) -no (550)) / (no (550) -no (650)) ) / ((Ne (450) −ne (550)) / (ne (550) −ne (650))) ≦ −0.422m + 2.55 ... (B).

Optomer AL (trade name) manufactured by Japan Synthetic Rubber Co., Ltd. is used as the alignment films 11 and 14, and the first region 8a and the second region 8b in the liquid crystal layer 8 are set to 17: 3, and the liquid crystal cell 16 is formed. The cell thickness (thickness of the liquid crystal layer 8) was 5 μm, and the five liquid crystal display devices (Sample # 2) shown in Table 3 below were used.
1 to # 25) were prepared.

[0099]

[Table 3]

As the optical retardation plates 2 and 3, a discotic liquid crystal is applied to a transparent support (eg, triacetyl cellulose (TAC)), and the discotic liquid crystal is tilted and crosslinked to form the first retardation film. The retardation value (nc-na) × d is 0 nm, the second retardation value (na-nb) × d is 100 nm, and the direction of the main refractive index nb shown in FIG. 3 is from the z-axis direction in the xyz coordinate axes. An index ellipsoid having an inclination angle θ = 20 ° in which the direction of the main refractive index nc was inclined by about 20 ° in the direction of arrow A and the direction of the main refractive index nc was inclined by about 20 ° in the direction of arrow B from the x-axis direction was produced.

Further, for comparison, in the liquid crystal display device shown in the liquid crystal display device of FIG. 1, as the liquid crystal material of the liquid crystal layer 8, F {no (λ), ne (λ)} is the above formula (B).
Two liquid crystal display devices (Comparative Samples # 301 and # 302) shown in Table 3 above were produced in the same manner as this embodiment except that the liquid crystal material out of the range was used.

Table 4 below shows the results of visual evaluation of the tint of the samples # 21 to # 25 and the comparative samples # 301 and # 302 at viewing angles of 50 °, 60 ° and 70 °.

[0103]

[Table 4]

As shown in Table 4 above, the samples # 23 to # 25 of this embodiment showed no coloring even when tilted down to a viewing angle of 70 °, and the display characteristics were very good. Therefore, 1.00 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) ≦ −0.343 m + 2.26 It is understood that more excellent characteristics can be obtained.

In addition, samples # 21 and # of this embodiment are
For No. 22, coloring was observed at a viewing angle of 60 ° and a viewing angle of 70 °, but coloring was not confirmed up to a viewing angle of 50 °, and the display characteristics were good and it was at a level that could be used.

On the other hand, the comparative samples # 301 and # 302 were severely colored when tilted to a viewing angle of 50 ° and were not at a level that could be used.

(Embodiment 3) In the third embodiment, in the liquid crystal display device shown in FIG. 1, the material system shown in the second embodiment is blended as the liquid crystal material of the liquid crystal layer 8 to obtain an average alkyl chain for 1 mol. The length _{m of} (C _m H _{2m + 1} −) is set to 3.
40 ≦ m ≦ 3.90, the extraordinary refractive index ne (450) of the liquid crystal material with respect to light having a wavelength of 450 nm, the wavelength of 550 n
Extraordinary light refractive index ne (550) and wavelength 6 for m light
The degree of change of the extraordinary light refractive index ne (650) with respect to the light of 50 nm and the normal light refractive index n with respect to the light of wavelength 450 nm
o (450), the normal light refractive index no (550) for light having a wavelength of 550 nm, and the degree of change of the normal light refractive index no (650) for light having a wavelength of 650 nm are 0.80 ≦ ((no (450) -no ( (550)) / (no (550) -no (650))) / ((ne (450) -ne (550)) / (ne (550) -ne (650))) ≦ 1.20 The one set in the range of C) was used.

Optomer AL (trade name) manufactured by Nippon Synthetic Rubber Co., Ltd. is used as the alignment films 11 and 14, and the first region 8a and the second region 8b of the liquid crystal layer 8 are set to 17: 3, and the liquid crystal cell 16 is formed. The cell thickness (thickness of the liquid crystal layer 8) was 5 μm, and the five liquid crystal display devices (Sample # 3) shown in Table 5 below were used.
1 to # 35) were produced.

[0109]

[Table 5]

As the optical retardation plates 2 and 3, a discotic liquid crystal is applied to a transparent support (eg, triacetyl cellulose (TAC)), and the discotic liquid crystal is tilted and crosslinked to form a first optical disc. The retardation value (nc-na) × d is 0 nm, the second retardation value (na-nb) × d is 100 nm, and the direction of the main refractive index nb shown in FIG. 3 is from the z-axis direction in the xyz coordinate axes. An index ellipsoid having an inclination angle θ = 20 ° in which the direction of the main refractive index nc was inclined by about 20 ° in the direction of arrow A and the direction of the main refractive index nc was inclined by about 20 ° in the direction of arrow B from the x-axis direction was produced.

Further, for comparison, in the liquid crystal display device shown in the liquid crystal display device of FIG. 1, as the liquid crystal material of the liquid crystal layer 8, F {no (λ), ne (λ)} is the above formula (C).
Two liquid crystal display devices (Comparative Samples # 401 and # 402) shown in Table 3 above were produced in the same manner as this embodiment except that a liquid crystal material out of the range was used.

Table 6 below shows the results of visual evaluation of the tint of the above Samples # 31 to # 35 and Comparative Samples # 401 and # 402 at visual angles of 50 °, 60 ° and 70 °.

[0113]

[Table 6]

As shown in Table 6 above, the samples # 32 to # 34 of this embodiment were not confirmed to be colored even when tilted to a visual angle of 70 °, and the display characteristics were very good. Therefore, 0.85 <((no (450) -no (550)) /
(No (550) -no (650))) / ((ne (4
50) -ne (550)) / (ne (550) -ne
(650))) <1.15, it can be seen that more excellent characteristics are obtained.

In addition, samples # 31 and # of this embodiment are
Regarding No. 35, coloring was observed at a viewing angle of 60 ° and a viewing angle of 70 °, but coloring was not confirmed up to a viewing angle of 50 °, and the display characteristics were good and it was a level that could be used.

On the other hand, in Comparative Samples # 401 and # 402, when they were tilted down to a viewing angle of 50 °, they were severely colored and were not at a level that they could be used.

(Embodiment 4) In Embodiment 4, the alignment film 1 of the liquid crystal cell 16 in the liquid crystal display device shown in FIG.
Optomer AL manufactured by Japan Synthetic Rubber Co., Ltd. is used as 1 and 14, and the refractive index anisotropy Δn (550) for light having a wavelength of 550 nm is 0.070, 0.080 for this alignment film.
The material set to 0.095 was used as the material of the liquid crystal layer 8. In the liquid crystal layer 8, the division ratio of the regions having different alignment states is 17: 3, and the cell thickness of the liquid crystal cell 16 is 5 μm.
Two liquid crystal display devices (Samples # 41 to # 43) were manufactured. In each sample, the average alkyl chain length m and F {no (λ), ne (λ)} of the liquid crystal material were set as shown in Table 7 below.

[0118]

[Table 7]

As the retardation plates 2 and 3, the same ones as those in the above-described first embodiment in which the discotic liquid crystal is tilted and aligned are used.

Further, for comparison, in the liquid crystal display device shown in the liquid crystal display device of FIG. 1, as the liquid crystal material of the liquid crystal layer 8, the refractive index anisotropy Δn with respect to light having a wavelength of 550 nm is Δn.
Two liquid crystal display devices (comparative samples # 501 and # 502) were manufactured in the same manner as in the present embodiment except that those in which (550) was set to 0.060 and 0.120 were used.

The samples # 41 to # 43 and the comparative samples # 501 and # 502 were set in a measuring system including the light receiving element 18, the amplifier 19 and the recording device 20 as shown in FIG. I went.

In this measurement system, the surface 16a of the liquid crystal cell 16 of the liquid crystal display device on the glass substrate 9 side is the orthogonal coordinate axis xy.
It is installed at the position of the reference plane xy of z. In addition, the light receiving element 18 capable of receiving light at a constant stereoscopic light receiving angle has an angle φ with respect to the z direction perpendicular to the surface 16 a of the liquid crystal cell 16.
It is arranged at a position spaced a predetermined distance from the coordinate origin in the direction of (visual angle).

At the time of measurement, the wavelength of 550 nm from the surface opposite to the surface 16a with respect to the liquid crystal cell 16 installed in the measurement system.
Of monochromatic light. As a result, a part of the monochromatic light transmitted through the liquid crystal cell 16 is incident on the light receiving element 18. Then, the output of the light receiving element 18 is amplified to a predetermined level by the amplifier 19, and then recorded by the recording device 20 including a waveform memory, a recorder, and the like.

Sample # 41 of this embodiment was added to this measurement system.
~ # 43 and comparative samples # 501, # 502 were installed, and the relationship between the voltage applied to each liquid crystal display device and the output level of the light receiving element 18 when the light receiving element 18 was fixed at a constant angle φ was measured. .

Here, it is assumed that the light receiving element 18 is arranged so that the angle φ is 50 °, the x direction is the lower side of the screen (normal viewing angle direction), and the y direction is the left side of the screen. The measurement was performed by changing the arrangement position of the light receiving element 18 in the upward direction (counter-viewing angle direction) and in the lateral direction.

The measurement results of samples # 41 to # 43 of this embodiment are shown in FIGS. 6 (a) to 6 (c), and the measurement results of comparative samples # 501 and # 502 are shown in FIG. 7 (a).
~ (C). 6 (a)-(c) and 7 (a)-
FIG. 6C is a graph showing the light transmittance (transmittance-liquid crystal applied voltage characteristic) with respect to the voltage applied to each liquid crystal display device, and FIG. 6A and FIG. 7A are measured from above. 6 (b) and 7 (b) are the results of measurement from the right direction, and FIGS. 6 (c) and 7 (c).
Is the result of measurement from the left.

In FIGS. 6A to 6C, the curves L21, L24, and L27 indicated by the alternate long and short dash line are Δ in the liquid crystal layer 8.
Curves L22, L25, L2 shown by solid lines are shown for sample # 41 using a liquid crystal material of n (550) = 0.070.
Reference numeral 8 denotes Sample # 42 in which a liquid crystal material of Δn (550) = 0.080 is used for the liquid crystal layer 8, and a curved line L2 shown by a dotted line.
3, L26 and L29 are Δn (550) = 0.
Sample # 43 using the 095 liquid crystal material is shown. Figure 7
In (a) to (c), the curve L310 shown by the solid line,
Ln and L34 are Δn (550) = 0.06 in the liquid crystal layer 8.
The comparative sample # 501 using the liquid crystal material of No. 0 is shown, and the curves L31, L33, and L35 indicated by the dotted lines are Δ in the liquid crystal layer 8.
A comparative sample # 502 using a liquid crystal material of n (550) = 0.120 is shown.

Regarding the transmittance-liquid crystal applied voltage characteristic in the upward direction, FIG. 6 shows the samples # 41 to # 43 of this embodiment.
As shown in L21 to L23 of (a), it was confirmed that the transmittance was sufficiently decreased as the voltage was increased. On the other hand, in comparison sample # 502, L3 in FIG.
As shown in FIG. 1, the transmittance does not decrease sufficiently even when the voltage is increased, and in the comparative sample # 501, as shown by L30 in FIG. 7A, the transmittance once decreases as the voltage increases. After that, the reversal phenomenon was seen to rise again.

Similarly, regarding the transmittance-liquid crystal applied voltage characteristic in the right direction, in the samples # 41 to # 43 of this embodiment, as shown by L24 to L26 in FIG. 6B, the voltage becomes high. Accordingly, it was confirmed that the transmittance decreased to almost zero. On the other hand, in the comparative sample # 501, FIG.
As indicated by L32 in (b), the transmittance decreases to almost 0 as the voltage increases.
In 502, as shown by L33 in FIG. 7B, an inversion phenomenon was observed in which the transmittance once decreased as the voltage increased and then increased again.

Similarly, regarding the transmittance-liquid crystal applied voltage characteristic in the left direction, in the samples # 41 to # 43 of this embodiment, as shown by L27 to L29 in FIG. 6C, the voltage becomes high. Accordingly, it was confirmed that the transmittance decreased to almost zero. On the other hand, in the comparative sample # 501, FIG.
As indicated by L34 in (c), the transmittance decreases to nearly 0 as the voltage increases, but the comparative sample #
In 502, as shown by L35 in FIG. 7C, an inversion phenomenon was observed in which the transmittance once decreased as the voltage increased and then increased again.

From the above results, the liquid crystal material of the liquid crystal layer 8 has a refractive index anisotropy Δn (55
0) is set to 0.070, 0.080, 0.095 according to the present embodiment (samples # 41 to # 43).
Then, as shown in FIGS. 6A to 6C, it can be seen that a liquid crystal display device having a wide viewing angle and excellent viewing angle characteristics without inversion phenomenon can be realized.

On the other hand, as the liquid crystal material of the liquid crystal layer 8, the refractive index anisotropy Δn (55
0) is set to 0.060 and 0.120, and the liquid crystal display device (comparative samples # 501 and # 502) has a configuration shown in FIG.
As shown in (a) to FIG. 7 (c), it can be seen that the inversion phenomenon occurs and the transmittance upon voltage application is not sufficiently reduced, which is not a level that can be practically endured.

Furthermore, as a result of examining the dependence of the transmittance-liquid crystal applied voltage characteristic on the tilt angle θ by changing the tilt angle θ of the refractive index ellipsoids of the optical retardation plates 2 and 3, as a result, 15
It has been found that when the angle is in the range of ≤θ≤75 °, the optical compensation effect of the optical phase difference plate on the liquid crystal layer becomes reliable, and a liquid crystal display device with a wide viewing angle can be realized.

On the other hand, with the optical retardation plate having an inclination angle of less than 15 ° or more than 75 °, the viewing angle was not widened and sufficient viewing angle characteristics could not be obtained. In the case of the optical retardation plate having an inclination angle of less than 15 ° or more than 75 °, the viewing angle in the counter-viewing angle direction tends to be narrowed.

Furthermore, as a result of examining the influence on the viewing angle characteristics by changing the second retardation value (na-nb) × d of the optical retardation plates 2 and 3, this value is 80 nm.
It has been found that when the thickness is in the range of 250 nm or less, the optical compensation effect on the liquid crystal layer of the optical retardation plate becomes reliable, and a liquid crystal display device having a wide viewing angle can be realized.

On the other hand, the optical retardation plate having the second retardation value (na-nb) × d of less than 80 nm or more than 250 nm did not widen the viewing angle and could not provide sufficient viewing angle characteristics. Second retardation value (na
In the optical retardation plate having a −nb) × d of less than 80 nm or more than 250 nm, the viewing angle in the left-right direction tends to be narrowed.

(Fifth Embodiment) In the fifth embodiment, in the liquid crystal display device shown in FIG. 1, the alignment film 1 of the liquid crystal cell 16 is formed.
Optomer AL manufactured by Japan Synthetic Rubber Co., Ltd. is used as 1 and 14, the cell thickness of the liquid crystal cell 16 is 5 μm, and the division ratio (first region 8a:
Three liquid crystal display devices (samples # 1 to # 3) in which the second region 8b) was 6: 4, 17: 3, and 19: 1 were produced. In each sample, the average alkyl chain length of the liquid crystal material, m, F
{No (λ), ne (λ)} is set as shown in Table 8 below.

[0138]

[Table 8]

As the retardation plates 2 and 3, the same ones as those in the first embodiment in which the discotic liquid crystal is tilted and aligned are used.

An experiment for verifying the influence of the ratio of the first region 8a and the second region 8b on the viewing angle characteristics by using the measurement system including the light receiving element 18, the amplifier 19 and the recording device 20 shown in FIG. I went.

In this measuring system, the liquid crystal cell 16 of the liquid crystal display device has a surface 1 on the glass substrate 9 side as in the fourth embodiment.
6a was installed so as to be at the position of the reference plane xy of the Cartesian coordinate axis xyz. Further, the light receiving element 18 capable of receiving light at a constant stereoscopic light receiving angle is located at a position a predetermined distance from the coordinate origin in a direction forming an angle φ (visual angle) with respect to the z direction perpendicular to the surface 16a of the liquid crystal cell 16. I placed it.

At the time of measurement, the wavelength of 550 nm from the surface opposite to the surface 16a with respect to the liquid crystal cell 16 installed in the measurement system.
Of monochromatic light. As a result, part of the monochromatic light that has passed through the liquid crystal cell 16 is incident on the light receiving element 18, the output of the light receiving element 18 is amplified to a predetermined level by the amplifier 19, and then recording provided with a waveform memory, a recorder, or the like. Recorded by device 20.

Sample # 1 of this embodiment was added to this measurement system.
~ # 3 installed, when the light receiving element 18 is fixed at a constant angle φ, the voltage applied to each liquid crystal display device and the light receiving element 18
The relationship with the output level of was measured.

Here, the light receiving element 18 is arranged so that the angle φ is 30 °, and it is assumed that the y direction is the left side of the screen, and the light receiving element 18 is arranged in the upward direction (counter-viewing angle direction). The measurement was carried out by changing downward (normal viewing angle direction), leftward and rightward.

The measurement results at this time are shown in FIGS.
Shown in. FIGS. 8A to 8C are graphs showing the light transmittance (transmittance-liquid crystal applied voltage characteristic) with respect to the voltage applied to each liquid crystal display device, and FIG. Four
8C is the measurement result of Sample # 1 of FIG. 8B, and FIG. 8B is the measurement result of Sample # 2 with a division ratio of 17: 3.
Is the measurement result of sample # 3 having a division ratio of 19: 1.

In FIGS. 8A to 8C, the curve L1 shown by the solid line is the z-axis direction, the curve L2 shown by the broken line is the downward direction, the curve L3 shown by the dotted line is the right direction, and the one-dot chain line is shown. The curved line L4 indicates the characteristic in the upward direction, and the curved line L5 indicated by the chain double-dashed line indicates the characteristic in the leftward direction.

As can be seen from FIG. 8B, the division ratio 1
In the sample # 2 of 7: 3, the curves L2 to L5 are close to the curve L1 in the transmittance-applied voltage characteristic in the halftone display region. Therefore, in the halftone display area, almost the same viewing angle characteristics can be obtained even if the viewing angle is tilted in any of the up, down, left, and right directions of the screen.

In the downward measurement, the transmittance was kept constant at a low value of about 7% in the ON state, and no reversal phenomenon was confirmed. In the measurement in the upward direction, the transmittance in the ON state was lower than the transmittance measured in the downward direction, and it was confirmed that the transmittance was sufficiently lowered.

Sample # 1 shown in FIG. 8A and FIG.
Also in sample # 3 shown in (c), almost the same improvement in viewing angle characteristics was observed.

For example, as shown in FIG. 8A, in sample # 1 having a division ratio of 6: 4, the curve L2 (downward) tends to approach the curve L4 (upward) in the halftone display area and in the ON state. Appears, and the tendency becomes stronger as the division ratio becomes larger. On the other hand, as shown in FIG. 8C, the division ratio is 1
In sample # 3 of 9: 1, the curve L2 (downward) tends to approach the curve L1 (z-axis direction) in the halftone display region and the ON state, and the tendency becomes stronger as the division ratio becomes smaller. This suppresses the phenomenon in which the black gradation of the display image is collapsed in the downward direction (normal viewing angle direction).

As a result of further detailed examination, the division ratio was 7: 3.
In the range of ~ 9: 1, the above-mentioned 17: 3 sample # 3
As described above, it was confirmed that there is a good improvement in the viewing angle characteristics that is well balanced in the downward direction and the upward direction.

Further, for comparison, a comparative sample # 101 in which the first region 8a of the liquid crystal layer 8 and the second region 8b of the liquid crystal layer 8 were set to 1: 1 was prepared and placed in the measurement system shown in FIG. Dependence positive was measured. The result is shown in FIG.

In FIG. 9, the curve L1 shown by the solid line
1 is the z-axis direction, the curved line L12 indicated by the broken line is downward, the curved line L13 indicated by the dotted line is in the right direction, and the curved line L indicated by the alternate long and short dash line.
14 shows the characteristic in the upward direction, and the curve L15 shown by the chain double-dashed line shows the characteristic in the left direction.

As can be seen from FIG. 9, in the left-right direction, a sufficiently low transmittance is obtained in the ON state, and there is no problem in the viewing angle characteristics. However, in the vertical direction, the transmittance is not sufficiently reduced in the ON state, and it can be seen that the vertical direction has a viewing angle dependency.

It should be noted that, here, two liquid crystal display elements are provided on both sides of the liquid crystal display element 1.
Although the optical retardation plates 2 and 3 are arranged, the above viewing angle characteristics can be obtained even if only one of them is arranged on one side of the liquid crystal display element 1. However, when the number of optical retardation plates is one, the vertical viewing angle characteristics are balanced and improved, but the horizontal viewing angle characteristics may become asymmetric. On the other hand, when two sheets are provided, the viewing angle characteristics in the vertical direction are improved as in the case of one sheet, and the viewing angle characteristics in the left and right directions are also symmetrical, so that the viewing angle characteristics are improved both in the vertical and horizontal directions.
Further, when two optical retardation plates are arranged, both of them may be arranged so as to be overlapped on one side of the liquid crystal display element 1. Furthermore, 3
It is also possible to use one or more retardation plates.

[0156]

As described above in detail, according to the present invention, a liquid crystal display device in which a liquid crystal layer is divided into a plurality of regions having different alignment states in each pixel at different ratios, and a refractive index ellipsoid is inclined. By combining with the optical retardation element having negative uniaxial property, the viewing angle is expanded in the left-right direction (3 o'clock to 9 o'clock direction) of the display screen and the vertical direction (6 o'clock to 12 o'clock).
A wide viewing angle in the time direction) can be realized.
In particular, in the upward direction (counter-viewing angle direction), it is possible to sufficiently reduce the transmittance when a voltage is applied, and in the downward direction (normal viewing angle direction), it is possible to reduce the phenomenon of black gradation collapse when a voltage is applied.

In addition, by optimizing the combination conditions of the average alkyl chain length of the liquid crystal material, the degree of change of the normal light refractive index no with respect to the wavelength, and the extraordinary light refractive index ne, when the viewing angle is lowered or the halftone is changed. Coloring of the display screen during display can be suppressed. Therefore, it is possible to realize a liquid crystal display device having a wide viewing angle, high contrast, and display characteristics excellent in visibility without coloring of the display screen.

Further, according to the present invention, it is possible to realize a liquid crystal display device having a display characteristic of excellent visibility without coloring even when the viewing angle is tilted up to 50 °.

In particular, according to the present invention, it is possible to realize a liquid crystal display device having display characteristics with excellent visibility without coloring even when the viewing angle is tilted to 70 °.

In the present invention, the refractive index anisotropy Δn (550) of the liquid crystal material with respect to light having a wavelength of 550 nm is 0.060 <
By setting the range of Δn (550) <0.120, it is possible to sufficiently reduce the transmittance at the time of voltage application and prevent the inversion phenomenon and the contrast ratio from being lowered.

In particular, in the present invention, the refractive index anisotropy Δn (550) of the liquid crystal material with respect to light having a wavelength of 550 nm is 0.0.
By setting the range of 70 ≦ Δn (550) ≦ 0.095, it is possible to further reduce the transmittance when a voltage is applied and to reliably prevent the reversal phenomenon and the contrast ratio from decreasing.

In the present invention, the optical compensating function of the optical phase difference element with respect to the liquid crystal layer is ensured by setting the inclination angle of the refractive index ellipsoid in the optical phase difference element within the range of 15 ° or more and 75 ° or less. As a result, a liquid crystal display device having a wide viewing angle and high contrast display characteristics can be realized.

In the present invention, the main refractive index n of the optical phase difference element is
By setting the product (na−nb) × d of the difference between a and nb and the thickness d in the range of 80 nm or more and 250 nm or less, it is possible to reliably obtain the optical compensation function for the liquid crystal layer of the optical retardation element. Therefore, it is possible to realize a liquid crystal display device having a wide viewing angle and high contrast display characteristics.

In the present invention, the liquid crystal display element and the optical position are arranged so that the orientation processing direction of the orientation film and the inclination direction of the main refractive indices nb and nc of the optical phase difference element are opposite to each other in the largest area in the pixel. By disposing the phase difference element, the rising direction of the liquid crystal molecules when a voltage is applied and the tilting direction of the refractive index ellipsoid of the optical phase difference plate are opposite to each other. With this, the optical anisotropy associated with the rising of the liquid crystal molecules can be reliably compensated by the optical retardation plate, so that a liquid crystal display device having a wide viewing angle and high contrast display characteristics can be realized.

In particular, in the present invention, the liquid crystal display element is arranged so that the orientation processing direction of the orientation film and the tilt direction of the main refractive indices nb and nc of the optical phase difference element are the same in the smallest area in the pixel. By arranging the optical retardation element, the smallest area in the pixel has a viewing angle characteristic opposite to the largest area in the pixel, and adding this component reduces the collapse of the black gradation in the largest area. It is possible to increase the viewing angle in the vertical direction.

Further, in the present invention, the ratio of the first region and the second region of the liquid crystal layer in each pixel is 6: 4 or more and 19: 1.
By increasing the viewing angle in the left-right direction,
It is possible to improve the contrast in the upward direction (counter-viewing angle direction) and suppress the collapse of black gradation when a voltage is applied in the downward direction (normal viewing angle direction). Therefore, it is possible to realize a liquid crystal display device having a wide viewing angle, high contrast, and excellent visibility.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a liquid crystal display device which is an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a rubbing direction of an alignment film in the liquid crystal display device of FIG.

3 is a perspective view showing a direction of a main refractive index of an optical retardation plate in the liquid crystal display device of FIG.

4 is a perspective view showing an optical arrangement of a liquid crystal display element, a polarizing plate and an optical retardation plate in the liquid crystal display device of FIG.

FIG. 5 is a perspective view showing a measurement system for measuring the viewing angle dependence of the liquid crystal display device.

FIG. 6 is a graph showing the transmittance-liquid crystal applied voltage characteristics of the liquid crystal display device of Embodiment 4.

FIG. 7 is a graph showing a transmittance-liquid crystal applied voltage characteristic of a liquid crystal display device of a comparative example.

FIG. 8 is a graph showing transmittance-liquid crystal applied voltage characteristics of the liquid crystal display device of the fifth embodiment.

FIG. 9 is a graph showing transmittance-liquid crystal applied voltage characteristics of a liquid crystal display device of a comparative example.

[Explanation of symbols]

1 Liquid crystal display element 2,3 Optical retarder 4, 5 Polarizer 6, 7 electrode substrate 8 Liquid crystal layer 8a First area 8b Second area 9, 12 translucent substrate 10, 13 Transparent electrode 11, 14 Alignment film 15 Seal resin 16 Liquid crystal cell 17 Drive circuit 18 Light receiving element 19 amplifier 20 recording device

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/13-1/141

Claims (13)

(57) [Claims] 1. A liquid crystal display element in which a liquid crystal layer is sandwiched between a pair of substrates, and an alignment film is provided on the surface of at least one substrate on the liquid crystal layer side, and a pair of liquid crystal display elements sandwiching both sides of the liquid crystal display element. A plurality of regions having a polarizer and at least one polarizer and at least one optical retardation element provided between the liquid crystal display elements, wherein the liquid crystal layer has different alignment states of liquid crystals in each pixel. In a liquid crystal display device in which the ratio of each region occupied in a pixel is different, the three main refractive indices n of the refractive index ellipsoid of the optical retardation element are divided into
a, nb, and nc have a relationship of na = nc> nb, and the direction of the main refractive index nb is a clock from the direction normal to the surface with the main refractive index na substantially parallel to the surface of the optical phase difference element as an axis. In addition to tilting clockwise or counterclockwise, the direction of the main refractive index nc is tilted clockwise or counterclockwise from the direction substantially parallel to the surface, and the average alkyl chain (CmH2m + 1- ) Length m
Is set in the range of m> 3.90, and the wavelength of the liquid crystal material is 4
Extraordinary light refractive index ne (450) for 50 nm light, wave
Extraordinary refractive index ne (550) for long 550 nm light
And the extraordinary refractive index ne (6
50) and the normal light refractive index n for light with a wavelength of 450 nm
o (450), normal light refraction for light of wavelength 550nm
Normal for rate no (550) and light of wavelength 650nm
Optical refractive index no (650) is -0.422m + 2.5
5 ≦ ((no (450) −no (550)) / (no
(550) -no (650))) / ((ne (450))
-Ne (550)) / (ne (550) -ne (65
0))) ≦ 1.00 liquid crystal display device
Place 2. An extraordinary refractive index ne (450) for light having a wavelength of 450 nm, an extraordinary refractive index ne (550) for light having a wavelength of 550 nm, and a wavelength of 650n.
The extraordinary refractive index ne (650) for the light of m and the wavelength 4
Normal light refractive index no (450) for 50 nm light, normal light refractive index no (550) for wavelength 550 nm
And the normal light refractive index no (6
50) and -0.343m + 2.26≤ ((no (4
50) -no (550)) / (no (550) -no
(650))) / ((ne (450) -ne (55
0)) / (ne (550) -ne (650))) ≦ 1.
The liquid crystal display device according to claim 1, wherein the liquid crystal display device is set in a range of 00. 3. A liquid crystal layer is sandwiched between a pair of substrates,
Alignment film is not provided on the surface of the liquid crystal layer side of one substrate.
Sandwich the liquid crystal display element and the both sides of the liquid crystal display element
A pair of polarizers, at least one polarizer and the liquid crystal surface
At least one optical phase difference element provided between the optical elements
And the liquid crystal layer has different liquid crystal alignment states in each pixel.
The ratio of each area in the pixel
In a liquid crystal display device having different refractive indices, the three main refractive indices n of the refractive index ellipsoid of the optical retardation element are
a, nb and nc have a relationship of na = nc> nb,
The main refractive index na, which is substantially parallel to the surface of the optical phase difference element, is used as an axis.
Then, the direction of the main refractive index nb is rotated clockwise from the surface normal direction.
Or with a main refractive index nc while tilting counterclockwise
The direction is clockwise or counterclockwise from the direction approximately parallel to the surface
And the length m of the average alkyl chain (CmH2m + 1-) of the liquid crystal material.
Is set in the range of m <3.40, and the wavelength of the liquid crystal material is 4
Extraordinary light refractive index ne (450) for 50 nm light, wave
Extraordinary refractive index ne (550) for long 550 nm light
And the extraordinary refractive index ne (6
50) and the normal light refractive index n for light with a wavelength of 450 nm
o (450), normal light refraction for light of wavelength 550nm
Normal for rate no (550) and light of wavelength 650nm
The optical refractive index no (650) is 1.00 ≦ ((no (4
50) -no (550)) / (no (550) -no
(650))) / ((ne (450) -ne (55
0)) / (ne (550) -ne (650))) ≦ −
A liquid crystal display device set in the range of 0.422 m + 2.55. 4. An extraordinary light refractive index ne (450) for light having a wavelength of 450 nm, an extraordinary light refractive index ne (550) for light having a wavelength of 550 nm, and a wavelength of 650 n.
The extraordinary refractive index ne (650) for the light of m and the wavelength 4
Normal light refractive index no (450) for 50 nm light, normal light refractive index no (550) for wavelength 550 nm
And the normal light refractive index no (6
50) and 1.00 ≦ ((no (450) −no (5
50)) / (no (550) -no (650))) /
((Ne (450) -ne (550)) / (ne (55
0) -ne (650))) ≦ −0.343m + 2.26
The liquid crystal display device according to claim 3 , wherein the liquid crystal display device is set in the range. 5. A liquid crystal layer is sandwiched between a pair of substrates,
Alignment film is not provided on the surface of the liquid crystal layer side of one substrate.
Sandwich the liquid crystal display element and the both sides of the liquid crystal display element
A pair of polarizers, at least one polarizer and the liquid crystal surface
At least one optical phase difference element provided between the optical elements
And the liquid crystal layer has different liquid crystal alignment states in each pixel.
The ratio of each area in the pixel
In a liquid crystal display device having different refractive indices, the three main refractive indices n of the refractive index ellipsoid of the optical retardation element are
a, nb and nc have a relationship of na = nc> nb,
The main refractive index na, which is substantially parallel to the surface of the optical phase difference element, is used as an axis.
Then, the direction of the main refractive index nb is rotated clockwise from the surface normal direction.
Or with a main refractive index nc while tilting counterclockwise
The direction is clockwise or counterclockwise from the direction approximately parallel to the surface
And the length m of the average alkyl chain (CmH2m + 1-) of the liquid crystal material.
Is set in the range of 3.40 ≦ m ≦ 3.90, and the liquid crystal material is
Extraordinary refractive index ne (4
50), and an extraordinary light refractive index ne for light having a wavelength of 550 nm
(550) and extraordinary light refraction for light of wavelength 650 nm
Normal for rate ne (650) and light of wavelength 450nm
Light refractive index no (450), for light with a wavelength of 550 nm
Normal light Refractive index no (550) and light with wavelength 650nm
The normal light refractive index no (650) is 0.80 ≦
((No (450) -no (550)) / (no (55
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
A liquid crystal display device set in a range of ≤1.20. 6. An extraordinary light refractive index ne (450) for light of a wavelength of 450 nm, an extraordinary light refractive index ne (550) for light of a wavelength of 550 nm, and a wavelength of 650n of the liquid crystal material.
The extraordinary refractive index ne (650) for the light of m and the wavelength 4
Normal light refractive index no (450) for 50 nm light, normal light refractive index no (550) for wavelength 550 nm
And the normal light refractive index no (6
50) and 0.85 <((no (450) -no (5
50)) / (no (550) -no (650))) /
((Ne (450) -ne (550)) / (ne (55
The liquid crystal display device according to claim 5 , wherein the liquid crystal display device is set in the range of 0) -ne (650))) <1.15. 7. The refractive index anisotropy Δn (550) of the liquid crystal material with respect to light having a wavelength of 550 nm is set in the range of 0.060 <Δn (550) <0.120. 7. The liquid crystal display device according to any one of 6 . 8. refractive index anisotropy [Delta] n (550) of said liquid crystal material having a wavelength of 550nm to light, according to claim 7 which is set in a range of 0.070 ≦ Δn (550) ≦ 0.095 Liquid crystal display device. 9. The liquid crystal display device according to any one of the optical retardation claims inclination angle of the refractive index ellipsoid in the element is set in a range of 15 ° or more 75 ° or less to claim 1 to claim 8. 10. The product (na) of the difference between the main refractive indices na and nb of the optical retardation element and the thickness d of the optical retardation element.
-Nb) × d is the liquid crystal display device according to any one of claims 1 to 9 is set in the range of 80nm or more 250nm or less. 11. The alignment treatment direction of the alignment film and the tilt direction of the main refractive indices nb and nc of the optical retardation element are defined in a largest region in a pixel among a plurality of regions having different alignment states of the liquid crystal. 2. The liquid crystal display element and the optical retardation element are arranged so that they are in opposite directions.
11. The liquid crystal display device according to claim 10 . 12. The alignment treatment direction of the alignment film and the main refractive indices nb and n of the optical phase difference element in the smallest region in a pixel among a plurality of regions having different alignment states of the liquid crystal.
The liquid crystal display device according to claim 11 , wherein the liquid crystal display element and the optical retardation element are arranged so that the inclination direction of c is the same direction. 13. The liquid crystal layer is divided into two regions in each pixel, and the ratio of the first region and the second region in each pixel is set to a range of 6: 4 or more and 19: 1 or less. the liquid crystal display device according to any one of claims 1 to 12.