JPH11271762A - Liquid crystal display device - 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 degree of variation of the ordinary light refractive index of the liquid crystal material with wavelength or the degree of variation of extraordinary light refractive index with the wavelength is 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 the viewing angle of a display screen is improved by combining a liquid crystal display device and a retardation device having optical anisotropy.

[0002]

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

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

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

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

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

In the above-mentioned liquid crystal display device of the display system, since the contrast of the displayed image changes or the reversal phenomenon occurs depending on the direction and the angle at which the observer looks at the display screen, there is a wide viewing angle dependency. There is a problem that viewing angle characteristics of a visual field cannot be obtained.

In order to solve this problem, for example, Japanese Patent Laid-Open Publication No. Sho 57-1867835 discloses an orientation division method for dividing the orientation of a liquid crystal layer so as to generate a plurality of viewing angle characteristics in each pixel. Alternatively, Japanese Unexamined Patent Publication No. 7-234407
And Japanese Patent Application Laid-Open No. 7-248497 disclose a method of causing a liquid crystal to have a plurality of twist alignments in each pixel.

However, when the pixel is divided into two by the 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-6 o'clock direction)
There is a problem that the viewing angle characteristics are completely different between the right and left directions (3 o'clock and 9 o'clock directions). For example, if the viewing angle is lowered in the vertical direction, the light transmittance at the time of black display increases and the contrast becomes insufficient. In the horizontal direction, the contrast is good but the reversal phenomenon occurs.

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

Therefore, Japanese Patent Application Laid-Open Nos. 6-118406 and 6-194645 disclose a technique in which the above-described pixel division method is combined with an optical retardation plate.

First, JP-A-6-118406 discloses a liquid crystal in which the contrast is improved by inserting a film having optical anisotropy (optical retardation plate) between a liquid crystal display element and a polarizing plate. A display device is disclosed.

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

However, in a situation where a liquid crystal display device having an even wider viewing angle and a higher display quality is demanded as in today, the above-described pixel division method and a negative uniaxial optical retardation plate are combined. Is not enough. The reason is that in the above-described technology, the pixel division ratio is the same, so that the left-right direction can be improved by using a negative uniaxial optical retardation plate, but the vertical direction is the same as that of the conventional TN-LCD.
This is because the superposition of the 6 o'clock direction and the 12 o'clock direction in (twisted nematic liquid crystal display) is not so much improved only by using a negative uniaxial optical retardation plate.

Therefore, Japanese Patent Application Laid-Open No. 10-3081 discloses a technique that combines a pixel division method for dividing the inside of a pixel at different ratios with the above-mentioned optical retardation plate in which the refractive index ellipsoid is inclined. ing. In the liquid crystal display device disclosed in this publication, in a large divided region in each pixel, the tilt direction of the refractive index ellipsoid of the optical retardation plate and the direction of the pretilt of the liquid crystal molecules near the alignment film are opposite to each other. The liquid crystal display element and the optical retardation plate are arranged such that Thereby, the viewing angle in the vertical direction can be increased simultaneously with the viewing angle in the horizontal direction.

[0016]

However, in a situation where a liquid crystal display device having an even wider viewing angle, a higher display quality and an excellent color reproducibility is required today,
It is not always sufficient to combine the pixel division method of dividing the pixels at different ratios as described above with the optical retardation plate having the inclined refractive index ellipsoid.

For example, when the above-mentioned optical retardation plate (optically anisotropic film) is disposed 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. When matching between the wavelength dependence of the ratio and the refractive index of the optical retardation plate is poor, there is a problem that when the viewing angle is lowered or halftone display is performed, coloring becomes remarkable, and the state of a displayed image is significantly deteriorated. .

The present invention has been made to solve such problems of the prior art, and it is possible to enlarge the viewing angle in the vertical direction as well as in the horizontal direction. It is an object of the present invention to provide a liquid crystal display device capable of realizing high-quality image display at a wide viewing angle without coloring during display.

[0019]

According to the present invention, there is provided a liquid crystal display device comprising a liquid crystal layer sandwiched between a pair of substrates, and an alignment film provided on a surface of at least one of the substrates on the liquid crystal layer side. 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 element, wherein the liquid crystal layer is In a liquid crystal display device in which a pixel is divided into a plurality of regions having different alignment states of liquid crystal in each pixel, and each region occupies a different ratio in the pixel, the three main refractive indices na of the refractive index ellipsoid of the optical phase difference element are provided. , 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 phase difference element as an axis. And the direction of the main refractive index nc is inclined clockwise or counterclockwise from a direction substantially parallel to the surface, and
At least one of the degree of change of the normal light refractive index no to the wavelength of the liquid crystal material in the liquid crystal layer and the degree of change of the extraordinary light refractive index ne to the wavelength is set in a range in which the visual angle-dependent screen coloring does not occur. Therefore, the above object is achieved.

The liquid crystal material has an extraordinary light 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 650 nm.
Extraordinary refractive index ne (650) for the light of
A normal light refractive index no (450) for light having a wavelength of 0 nm, a normal light refractive index no (550) for light having a wavelength of 550 nm, and a normal light refractive index no (65) for light having a wavelength of 650 nm.
0) and ((no (450) -no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
≥ 1.00.

The liquid crystal material has an extraordinary light 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 650 nm.
Is 1.70 ≦ ((ne (450) −ne (550)) /
(Ne (550) -ne (650))) ≦ 2.30.

The liquid crystal material has 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 650 nm.
1.85 ≦ ((ne (450) -ne (550)) /
(Ne (550) -ne (650))) ≦ 2.10.

The liquid crystal material has a normal refractive index no (450) for light having a wavelength of 450 nm, a normal refractive index no (550) for light having a wavelength of 550 nm, and a wavelength of 650 nm.
The degree of change of the normal light refractive index no (650) with respect to the light of 1.65 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 2.40.

The liquid crystal material has 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.
Is 1.85 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 2.20.

The liquid crystal material has 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 650 nm.
Extraordinary refractive index ne (650) for the light of
A normal light refractive index no (450) for light having a wavelength of 0 nm, a normal light refractive index no (550) for light having a wavelength of 550 nm, and a normal light refractive index no (65) for light having a wavelength of 650 nm.
0) and ((no (450) -no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
<1.00.

The liquid crystal material has 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 650 nm.
Is 1.20 ≦ ((ne (450) −ne (550)) /
(Ne (550) -ne (650))) ≦ 1.70.

The liquid crystal material has 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 nm.
The degree of change of the extraordinary light refractive index ne (650) with respect to the light of 1.35 ≦ ((ne (450) −ne (550)) /
(Ne (550) -ne (650))) ≦ 1.60.

The liquid crystal material has a normal refractive index no (450) for light having a wavelength of 450 nm, a normal refractive index no (550) for light having a wavelength of 550 nm, and a wavelength of 650 nm.
The degree of change of the normal light refractive index no (650) with respect to the light of 1.00 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 1.65.

The liquid crystal material has a normal refractive index no (450) for light having a wavelength of 450 nm, a normal refractive index no (550) for light having a wavelength of 550 nm, and a wavelength of 650 nm.
Is 1.15 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 1.45.

It is preferable that 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.

It is preferable that 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 0.070 ≦ Δn (550) ≦ 0.095.

It is preferable that the inclination angle of the refractive index ellipsoid in the optical retardation element is set in a range from 15 ° to 75 °.

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

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

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

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

Hereinafter, the process of completing the present invention and the operation of the present invention will be described.

As described above, the liquid crystal display element 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 viewing angle in the vertical direction (6 o'clock to 12 o'clock) can be increased simultaneously with the expansion of the viewing angle in the time (-9 o'clock direction).

In this liquid crystal display device, the liquid crystal display element and the optical element are arranged such that the direction in which the liquid crystal molecules rise when voltage is applied in the largest region in the pixel is opposite to the direction in which the refractive index ellipsoid of the optical phase difference element is inclined. When the retardation element is disposed, the refractive index anisotropy of the liquid crystal molecules which rises with the application of a voltage in the largest region 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 lost. Therefore, in the smallest region in the pixel, the liquid crystal molecules are arranged so that the direction in which the liquid crystal molecules rise when voltage is applied is the same as the direction in which the refractive index ellipsoid of the optical phase difference element is inclined. In this case, since the minimum region has a viewing angle characteristic opposite to that of the maximum region, the addition of this component can reduce the loss of black gradation in the maximum region and increase the vertical viewing angle.

However, even in such a liquid crystal display device, the wavelength dependence of the normal refractive index no of the liquid crystal material, the wavelength dependence of the extraordinary refractive index ne of the liquid crystal material, and the wavelength dependence of the refractive index of the optical retardation plate. If the matching with the character is poor, coloring of the display screen becomes remarkable when the viewing angle is lowered or halftone display is performed, and the state of the display image is significantly deteriorated.

Therefore, the present invention realizes a high-quality liquid crystal display device with a high viewing angle and a high viewing angle, in which the viewing angle in the vertical direction is enlarged simultaneously with the left-right direction, and no coloring occurs when the viewing angle is lowered or halftone display is performed. To this end, design guidelines for the material of the liquid crystal layer were set.

In the liquid crystal display device of the present invention, at least one of the degree of change of the normal refractive index no of the liquid crystal material with respect to the wavelength and the extraordinary refractive index ne is determined so that the screen coloring depending on the viewing angle does not occur. Is set to This makes it possible to further prevent the coloring of the screen, and furthermore, as shown in an embodiment described later, the contrast change and the inversion phenomenon can be further improved as compared with the case where only the compensation function of the retardation plate is used. it can.

Specifically, the normal light refractive index no of the liquid crystal material
And the extraordinary refractive index n of the liquid crystal material
The degree of change of e with respect to the wavelength is set as follows.

(1) The extraordinary refractive index ne (450) of the liquid crystal material with respect to light having a wavelength of 450 nm, the extraordinary refractive index ne (550) with respect to light having a wavelength of 550 nm, and a wavelength of 650 n
m, the extraordinary light refractive index ne (650), and the wavelength 4
Normal light refractive index no (450) for light of 50 nm, normal light refractive index no (550) for light of wavelength 550 nm
And the normal light refractive index no (6
(50) and ((no (450) −no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
In the case of ≧ 1.00, the extraordinary light refractive index ne (450) for the liquid crystal material having a wavelength of 450 nm, the extraordinary light refractive index ne (550) for the light having a wavelength of 550 nm, and the wavelength of 650.
The degree of change of the extraordinary light refractive index ne (650) with respect to light of nm is 1.70 ≦ ((ne (450) −ne (550)) /
(Ne (550) -ne (650))) ≦ 2.30.

Alternatively, the liquid crystal material has a normal refractive index no (450) for light having a wavelength of 450 nm, a normal refractive index no (550) for light having a wavelength of 550 nm, and a wavelength 650 n.
The degree of change of the normal light refractive index no (650) with respect to light of m is 1.65 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 2.40.

When at least one of these ranges is set, as shown in Embodiments 1 and 2 described later, high-quality display with a wide viewing angle without coloring when the viewing angle is lowered or halftone display is performed. An image is obtained.

More preferably, 1.85 ≦ ((ne (450) -ne (550)) /
(Ne (550) -ne (650))) ≦ 2.10.

Or 1.85 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 2.20.

By setting at least one of these ranges, a display image having a wide viewing angle, high quality and excellent color reproducibility without further coloring can be obtained as shown in Embodiments 1 and 2 described later. can get.

(2) The extraordinary light refractive index ne (450) for light having a wavelength of 450 nm, the extraordinary light refractive index ne (550) for light having a wavelength of 550 nm, and the wavelength 650 n of the liquid crystal material.
m, the extraordinary light refractive index ne (650), and the wavelength 4
Normal light refractive index no (450) for light of 50 nm, normal light refractive index no (550) for light of wavelength 550 nm
And the normal light refractive index no (6
(50) and ((no (450) −no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
When the relationship of <1.00 is satisfied, the extraordinary light refractive index ne (450) for light having a wavelength of 450 nm, the extraordinary light refractive index ne (550) for light having a wavelength of 550 nm, and the wavelength 650 of the liquid crystal material.
The degree of change of the extraordinary light refractive index ne (650) with respect to light of nm is 1.20 ≦ ((ne (450) −ne (550)) /
(Ne (550) -ne (650))) ≦ 1.70.

Alternatively, the liquid crystal material has a normal refractive index no (450) for light having a wavelength of 450 nm, a normal refractive index no (550) for light having a wavelength of 550 nm, and a wavelength of 650 n.
The degree of change of the normal light refractive index no (650) with respect to light of m is 1.00 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 1.65.

By setting at least one of these ranges, as shown in Embodiments 3 and 4, which will be described later, when the viewing angle is lowered or halftone display is performed, high-quality display with a wide viewing angle without coloring is performed. An image is obtained.

More preferably, 1.35 ≦ ((ne (450) -ne (550)) /
(Ne (550) -ne (650))) ≦ 1.60.

Or 1.15 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 1.45.

By setting at least one of these ranges, as shown in Embodiments 3 and 4 to be described later, a display image having a wide viewing angle, high quality, and excellent color reproducibility without further coloring can be obtained. can get.

In the liquid crystal display device of the present invention, the wavelength 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, which is a visible light region.
This is because it has been confirmed that when (550) is 0.060 or less or 0.120 or more, an inversion phenomenon or a decrease in contrast ratio occurs depending on the viewing angle direction as described in a fifth embodiment described later. Therefore, by setting the refractive index anisotropy Δn (550) of the liquid crystal material to light having a wavelength of 550 nm in a range larger than 0.060 and smaller than 0.120, a phase difference according to a viewing angle can be eliminated. In the liquid crystal display screen, a change in contrast, a reversal phenomenon in the left-right direction, and the like can be further improved.

Further, by setting the refractive index anisotropy Δn (550) of the liquid crystal material to light having a wavelength of 550 nm in the range of 0.070 ≦ Δn (550) ≦ 0.095, a fifth embodiment described later will be described. Thus, the phase difference generated in the liquid crystal display element according to the viewing angle can be more effectively and reliably eliminated. Therefore,
It is possible to reliably improve the contrast change and the left-right inversion phenomenon on the liquid crystal display screen.

In the liquid crystal display device of the present invention, the inclination angle of the refractive index ellipsoid in the optical retardation element is set to 15 ° or more and 7 ° or more.
It is preferable to set the range to 5 ° or less. By setting the inclination angle of the refractive index ellipsoid in this manner, the compensation function by the optical phase difference element can be reliably obtained as described in a fifth embodiment described later.

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 set in the range from 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 phase difference element and the thickness d in this manner, the compensation function by the optical phase difference element is reliably obtained as described in a fifth embodiment described later. be able to.

In the liquid crystal display device of the present invention, the orientation treatment direction (rubbing direction) of the orientation film and the main phase of the optical retardation element are the largest in the pixel among the plurality of regions in which the orientation state of the liquid crystal is different. It is preferable that the refractive indices nb and nc are arranged so that the inclination directions are opposite to each other. By arranging in this manner, the direction in which the liquid crystal molecules rise when a voltage is applied and the inclination direction of the refractive index ellipsoid of the optical retardation plate are opposite to each other. Compensation can be ensured by the optical phase difference plate.

Further, in the smallest region in the pixel, the alignment processing 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 such that the inclination direction of c is the same as the inclination direction. in this case,
Since the smallest region in a pixel has a viewing angle characteristic opposite to that of the largest region in a pixel, the addition of this component reduces the loss of black gradation in the largest region and expands the viewing angle in the vertical direction. Can be.

When the liquid crystal layer is divided into two regions in each pixel, the ratio between the first region and the second region in each pixel is set in a range from 6: 4 to 19: 1. Is preferred. By setting this range, as will be described in a sixth embodiment described later, the vertical contrast is improved and the black inversion is reduced, and the black gradation is reduced to increase the vertical viewing angle. Can be.

[0063]

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 one embodiment of the present invention. This 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, 3 and a pair of polarizing plates (polarizers) 4, 5, and a driving 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 opposite to each other. On one electrode substrate 6, a transparent electrode 10 made of ITO (indium tin oxide) is formed on the surface of a glass substrate (light transmitting substrate) 9 serving as a base on the liquid crystal layer 8 side, and an alignment film 11 is formed thereon. Is formed. The other electrode substrate 7
A transparent electrode 13 made of ITO is formed on the surface of a glass substrate (translucent substrate) 12 serving as a base on the liquid crystal layer 8 side, and an alignment film 14 is formed thereon. Both transparent electrodes 10 and 11 are connected to a drive circuit 17.

It should be noted that in FIG.
Although the configuration for pixels is shown, strip-shaped transparent electrodes 10 and 13 having a predetermined width are provided over almost the entire display portion of the liquid crystal display element 1.
Are provided at predetermined intervals on the glass substrates 9 and 12,
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 cross each other (here, orthogonal) when viewed from a direction perpendicular to the substrate surface.

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

The two electrode substrates 6 and 7 are bonded to each other with a sealing resin 15, and the electrode substrates 6 and 7 and the sealing resin 1 are bonded together.
The liquid crystal layer 8 is sealed 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 surface of the electrode substrates 6 and 7 on the liquid crystal layer 8 side have two regions having different states, and a pretilt applied to liquid crystal molecules between the two regions. The angles may be different, or the pretilt directions of the liquid crystal molecules may be opposite to each other with respect to the direction perpendicular to the substrate surface. Thereby, the liquid crystal layer 8 is controlled so that the alignment state of the liquid crystal molecules is different between the first region 8a facing one region of the alignment film and the second region 8b facing the other region.

Further, in this embodiment, in order to improve the viewing angle characteristics when the viewing angle is tilted in the vertical and horizontal directions, the alignment state of the liquid crystal layer 8 in one pixel is different as shown in FIG. 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. The arrow P1 indicates the alignment film 1 in the region 8a.
The rubbing direction on the first side, arrow P3 indicates the rubbing direction on the alignment film 14 side in the region 8a, arrow P2 indicates the rubbing direction on the alignment film 11 side in the region 8b, and arrow P4 indicates the rubbing direction on the region 8a.
The rubbing direction on the alignment film 14 side in FIG. By performing the rubbing process on the alignment films 11 and 14 in this manner, the inside of the pixel can be divided into the 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
The optical retardation plates 2 and 3 are arranged one by one between them. The optical retardation plates 2 and 3 are each formed by cross-linking a discotic liquid crystal in a tilted or hybrid orientation on a support made of a transparent organic polymer. Thereby, as described later, the retardation plates 2 and 3 in which the refractive index ellipsoid is inclined are obtained.

As the support material of the optical retardation plates 2 and 3, triacetyl cellulose (TAC), which is generally used as a material for a polarizing plate, is most suitable, and a highly reliable retardation plate can be obtained. Other materials include polycarbonate (PC) and polyethylene terephthalate (P
A colorless and transparent organic polymer film excellent in 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) among 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 is inclined from the direction of the z-axis perpendicular to the surface (normal direction of the surface, perpendicular to the screen) in the direction of arrow A by θ. Main refractive index nc
Is inclined by θ 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) with the direction of the main refractive index na as the axis. In FIG. 3, the main refractive index nb that is inclined in a direction for giving anisotropy to the retardation plates 2 and 3 is shown.
Is projected onto the surfaces of the phase difference plates 2 and 3 as 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 a product (nc−c) of the difference between the main refractive indices na and nc (refractive index anisotropy Δn) and the thickness d of the optical retardation plate. na) ×
Although represented by d, it is almost 0 nm because na = nc. The second retardation values are principal refractive indices na and nb
(Na−nb) × d of the difference (refractive index anisotropy Δn) and the thickness d of the optical retardation plate.
It is preferable to set the range to 0 nm or less. By setting this range, the phase difference compensation function by the optical phase difference plates 2 and 3 can be reliably obtained.

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

The absorption axis AX1 of the polarizing plate 4 corresponds to the above-mentioned region 8a.
And the absorption axis AX2 of the polarizing plate 5 is arranged so as to be parallel to the rubbing direction P3 on the alignment film 14 side in the region 8a. The optical retardation plate 2 is arranged such 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. The direction D (D2) is the area 8a
Are arranged in parallel with the rubbing direction P3 on the alignment film 14 side.

Further, in the liquid crystal layer 8 described above, the degree of change of the normal refractive index no of the liquid crystal material with respect to the wavelength and the abnormalities are considered in consideration of the matching of the refractive indices of the optical retardation plates 2 and 3 with the wavelength. The degree of change of the light refractive index ne 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 normal light refractive index no of the liquid crystal material
And the extraordinary refractive index n of the liquid crystal material
The degree of change with respect to the wavelength of e is set so as to satisfy the condition of at least one of the setting ranges in each of the following conditions (1) and (2).

(1) The extraordinary light refractive index ne (450) for light having a wavelength of 450 nm, the extraordinary light refractive index ne (550) for light having a wavelength of 550 nm, and the wavelength 650 n of the liquid crystal material.
m, the extraordinary light refractive index ne (650), and the wavelength 4
Normal light refractive index no (450) for light of 50 nm, normal light refractive index no (550) for light of wavelength 550 nm
And the normal light refractive index no (6
(50) and ((no (450) −no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
When the relationship of ≧ 1.00 is satisfied, the extraordinary light refractive index ne (450) for light having a wavelength of 450 nm, the extraordinary light refractive index ne (550) for light having a wavelength of 550 nm, and the extraordinary refractive index ne for light having a wavelength of 650 nm are obtained. The degree of change of (650) is calculated as follows: 1.70 ≦ ((ne (450) −ne (550)) /
(Ne (550) -ne (650))) ≦ 2.30.

More preferably, 1.85 ≦ ((ne (450) −ne (550)) /
(Ne (550) -ne (650))) ≦ 2.10.

The degree of change of the normal light refractive index no (450) for the light having a wavelength of 450 nm, the normal light refractive index no (550) for the light having a wavelength of 550 nm, and the normal light refractive index no (650) for the light having a wavelength of 650 nm of the liquid crystal material. 1.65 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 2.40.

More preferably, 1.85 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 2.20.

(2) The extraordinary light refractive index ne (450) for the light of wavelength 450 nm, the extraordinary light refractive index ne (550) for the light of wavelength 550 nm, and the wavelength 650 n of the liquid crystal material.
m, the extraordinary light refractive index ne (650), and the wavelength 4
Normal light refractive index no (450) for light of 50 nm, normal light refractive index no (550) for light of wavelength 550 nm
And the normal light refractive index no (6
(50) and ((no (450) −no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
<1.00 The extraordinary refractive index ne (450) of the liquid crystal material with respect to light having a wavelength of 450 nm, the extraordinary refractive index ne (550) with respect to light having a wavelength of 550 nm, and the extraordinary refractive index ne with respect to light having a wavelength of 650 nm. The degree of change of (650) is calculated as follows: 1.20 ≦ ((ne (450) −ne (550)) /
(Ne (550) -ne (650))) ≦ 1.70.

More preferably, 1.35 ≦ ((ne (450) −ne (550)) /
(Ne (550) -ne (650))) ≦ 1.60.

The degree of change of the normal light refractive index no (450) for the light of wavelength 450 nm, the normal light refractive index no (550) for the light of wavelength 550 nm, and the normal light refractive index no (650) of the liquid crystal material for light of wavelength 650 nm. 1.00 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 1.65.

More preferably, 1.15 ≦ ((no (450) −no (550)) /
(No (550) -no (650))) ≦ 1.45.

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

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

(Embodiment 1) In Embodiment 1, in the liquid crystal display device shown in FIG. 1, as a liquid crystal material of the liquid crystal layer 8, the extraordinary light refractive index ne (450) and the wavelength Abnormal light refractive index ne (550) for light of 550 nm, abnormal light refractive index ne (650) for light of 650 nm, normal light refractive index no (450) for light of 450 nm, and normal light refraction for light of 550 nm. Rate no (550) and wavelength 650
The normal light refractive index no (650) with respect to light of nm is represented by ((no (450) -no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
≧ 1.00, and 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 an extraordinary light refractive index ne (550) for light having a wavelength of 650 nm. 650) is set within the range of 1.70 ≦ ((ne (450) −ne (550)) / (ne (550) −ne (650))) ≦ 2.30 (A) What was done was used.

This liquid crystal material was prepared by blending a material system represented by the following structural formula.

[0094]

Embedded image

Optomer AL (trade name) manufactured by Japan Synthetic Rubber Co., Ltd. was used as the alignment films 11 and 14, and the first region 8 a and the second region 8 b in the liquid crystal layer 8 were set to 17: 3. Assuming that the cell thickness (the thickness of the liquid crystal layer 8) is 5 μm, the five liquid crystal display devices shown in Table 1 below (sample # 1)
1 to # 15).

As the optical retardation plates 2 and 3, a discotic liquid crystal is applied to a transparent support (for example, triacetyl cellulose (TAC) or the like), and the discotic liquid crystal is obliquely aligned and crosslinked to form the first. 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 on the xyz coordinate axis. A refractive index ellipsoid having a tilt angle θ = 20 ° was prepared in which the main refractive index nc was tilted by about 20 ° in the direction of arrow B from the x-axis direction by about 20 ° in the direction of arrow A.

Further, for comparison, in the liquid crystal display device shown in the liquid crystal display device of FIG. 1, the liquid crystal material of the liquid crystal layer 8 was ((ne (450) −ne (550))) / (ne (55)
0) -ne (650))), two liquid crystals shown in Table 1 below in the same manner as in the present embodiment except that those having the values of 1.60 and 2.40 outside the range of the above formula (A) were used. Display devices (comparative samples # 201 and # 202) were produced.

Table 1 below shows the results of visual evaluation of the tint of Samples # 11 to # 15 and Comparative Samples # 201 and # 202 at viewing angles of 50 °, 60 ° and 70 °. Table 1 below and Embodiments 2 to 4 described below.
In Tables 2 to 4, ○ indicates no coloring, Δ indicates coloring enough to endure use, and X indicates coloration not enduring use.

[0099]

[Table 1]

As shown in Table 1 above, with respect to Samples # 12 to # 14 of this embodiment, no coloring was observed even when the sample was tilted to a viewing angle of 70 °, and the display characteristics were very good. Therefore, 1.85 ≦ ((ne (450) −ne (550)) /
It can be seen that in the range of (ne (550) -ne (650))) ≦ 2.10, coloring is further suppressed and more excellent characteristics can be obtained.

Also, the samples # 11 and # 11 of this embodiment
As for No. 15, although coloring was observed at a viewing angle of 60 ° and a viewing angle of 70 °, no coloring was confirmed up to a viewing angle of 50 °, and the display characteristics were good and were at a level that could be used.

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

Embodiment 2 In Embodiment 2, in the liquid crystal display device shown in FIG. 1, as the liquid crystal material of the liquid crystal layer 8, the extraordinary light refractive index ne (450) and the wavelength Abnormal light refractive index ne (550) for light of 550 nm, abnormal light refractive index ne (650) for light of 650 nm, normal light refractive index no (450) for light of 450 nm, and normal light refraction for light of 550 nm. Rate no (550) and wavelength 650
The normal light refractive index no (650) with respect to light of nm is represented by ((no (450) -no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
.Gtoreq.1.00, and 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 normal light refractive index no (550) for light having a wavelength of 650 nm. 650) is set in the range of 1.65 ≦ ((no (450) −no (550)) / (no (550) −no (650))) ≦ 2.40 (B) What was done was used.

This liquid crystal material was prepared by blending the material system shown in the first embodiment.

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

As the optical retardation plates 2 and 3, a discotic liquid crystal is applied to a transparent support (for example, triacetyl cellulose (TAC) or the like), and the discotic liquid crystal is obliquely aligned and crosslinked to form a first liquid crystal. 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 on the xyz coordinate axis. A refractive index ellipsoid having a tilt angle θ = 20 ° was prepared in which the main refractive index nc was tilted by about 20 ° in the direction of arrow B from the x-axis direction by about 20 ° in the direction of arrow A.

Further, for comparison, in the liquid crystal display device shown in the liquid crystal display device of FIG. 1, the liquid crystal material of the liquid crystal layer 8 is ((no (450) -no (550)) / (no (55)
0) -no (650))), two liquid crystals shown in Table 2 below in the same manner as in the present embodiment except that those having the values of 1.55 and 2.50 outside the range of the above formula (B) were used. Display devices (comparative samples # 301 and # 302) were produced.

Table 2 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 °.

[0109]

[Table 2]

As shown in Table 2, with respect to Samples # 22 to # 24 of this embodiment, no coloring was observed even when the sample was tilted to a viewing angle of 70 °, and the display characteristics were very good. Therefore, 1.85 ≦ ((no (450) −no (550)) /
It can be seen that in the range of (no (550) -no (650))) ≦ 2.20, coloring is further suppressed and more excellent characteristics can be obtained.

Further, samples # 21 and # 21 of this embodiment
As for No. 25, although coloring was observed at a viewing angle of 60 ° and a viewing angle of 70 °, no coloring was observed up to a viewing angle of 50 °, and the display characteristics were good and were at a level that could be used.

On the other hand, with respect to Comparative Samples # 301 and # 302, when the viewing angle was lowered to 50 °, the coloring was intense and the level was not at a level that could be used.

Embodiment 3 In Embodiment 3, in the liquid crystal display device shown in FIG. 1, as a liquid crystal material of the liquid crystal layer 8, the extraordinary light refractive index ne (450) and the wavelength of the liquid crystal material for light having a wavelength of 450 nm are used. Abnormal light refractive index ne (550) for light of 550 nm, abnormal light refractive index ne (650) for light of 650 nm, normal light refractive index no (450) for light of 450 nm, and normal light refraction for light of 550 nm. Rate no (550) and wavelength 650
The normal light refractive index no (650) with respect to light of nm is represented by ((no (450) -no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
<1.00, and the extraordinary light refractive index ne (450) for light having a wavelength of 450 nm, the extraordinary light refractive index ne (550) for light having a wavelength of 550 nm, and the extraordinary refractive index ne (550) for light having a wavelength of 650 nm. 650) is set in the range of 1.20 ≦ ((ne (450) −ne (550)) / (ne (550) −ne (650))) ≦ 1.70 (C) What was done was used.

This liquid crystal material was prepared by blending the material system shown in the first embodiment.

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

As the optical retardation plates 2 and 3, a discotic liquid crystal is applied to a transparent support (for example, triacetyl cellulose (TAC) or the like), and the discotic liquid crystal is obliquely aligned and crosslinked to form a first liquid crystal. 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 on the xyz coordinate axis. A refractive index ellipsoid having a tilt angle θ = 20 ° was prepared in which the main refractive index nc was tilted by about 20 ° in the direction of arrow B from the x-axis direction by about 20 ° in the direction of arrow A.

For comparison, in the liquid crystal display device shown in FIG. 1, the liquid crystal material of the liquid crystal layer 8 is ((ne (450) -ne (550)) / (ne (55)
0) -ne (650))), two liquid crystals shown in Table 3 below in the same manner as in the present embodiment except that those having the values of 1.10 and 1.80 outside the range of the above formula (C) were used. Display devices (comparative samples # 401 and # 402) were produced.

Table 3 below shows the results of visual evaluation of the colors of the samples # 31 to # 35 and the comparative samples # 401 and # 402 at viewing angles of 50 °, 60 ° and 70 °.

[0119]

[Table 3]

As shown in Table 3 above, with respect to the samples # 32 to # 34 of this embodiment, no coloring was confirmed even when the sample was tilted to a viewing angle of 70 °, and the display characteristics were very good. Therefore, 1.35 ≦ ((ne (450) −ne (550)) /
In the range of (ne (550) -ne (650))) ≤1.60, it can be seen that coloring is further suppressed and more excellent characteristics can be obtained.

Also, samples # 31 and # of the present embodiment
With regard to No. 35, although coloring was observed at a viewing angle of 60 ° and a viewing angle of 70 °, no coloring was observed up to a viewing angle of 50 °, and the display characteristics were good and were at a level that could be used.

On the other hand, when the comparative samples # 401 and # 402 were tilted to a viewing angle of 50 °, the coloring was intense and the level was not at a level that could be used.

(Embodiment 4) In Embodiment 4, in the liquid crystal display device shown in FIG. 1, as a liquid crystal material of the liquid crystal layer 8, an extraordinary light refractive index ne (450) and a wavelength of 450 nm wavelength light of the liquid crystal material are used. Abnormal light refractive index ne (550) for light of 550 nm, abnormal light refractive index ne (650) for light of 650 nm, normal light refractive index no (450) for light of 450 nm, and normal light refraction for light of 550 nm. Rate no (550) and wavelength 650
The normal light refractive index no (650) with respect to light of nm is represented by ((no (450) -no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
<1.00, and the normal light refractive index no (450) for the light of wavelength 450 nm, the normal light refractive index no (550) for the light of wavelength 550 nm, and the normal light refractive index no (550) for the light of wavelength 650 nm of the liquid crystal material. 650) is set in the range of 1.00 ≦ ((no (450) −no (550)) / (no (550) −no (650))) ≦ 1.65 (D) What was done was used.

This liquid crystal material was prepared by blending the material system shown in the first embodiment.

Optomer AL (trade name) manufactured by Japan Synthetic Rubber Co., Ltd. was used as the alignment films 11 and 14, and the first region 8 a and the second region 8 b in the liquid crystal layer 8 were set to 17: 3. Assuming that the cell thickness (the thickness of the liquid crystal layer 8) is 5 μm, the five liquid crystal display devices shown in Table 4 below (sample # 4)
1 to # 45).

As the optical retardation plates 2 and 3, a discotic liquid crystal is applied to a transparent support (for example, triacetyl cellulose (TAC) or the like), and the discotic liquid crystal is obliquely aligned and crosslinked to form the first. 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 on the xyz coordinate axis. A refractive index ellipsoid having a tilt angle θ = 20 ° was prepared in which the main refractive index nc was tilted by about 20 ° in the direction of arrow B from the x-axis direction by about 20 ° in the direction of arrow A.

For comparison, in the liquid crystal display device shown in FIG. 1, the liquid crystal material of the liquid crystal layer 8 is ((no (450) -no (550)) / (no (55)
0) -no (650))), two liquid crystals shown in Table 4 below in the same manner as in the present embodiment except that those having 0.90 and 1.75 outside the range of the above formula (D) were used. Display devices (comparative samples # 501 and # 502) were produced.

Table 4 below shows the results of visual evaluation of the tint of Samples # 41 to # 45 and Comparative Samples # 501 and # 502 at viewing angles of 50 °, 60 ° and 70 °.

[0129]

[Table 4]

As shown in Table 4, with respect to the samples # 42 to # 44 of the present embodiment, no coloring was observed even when the sample was tilted to a viewing angle of 70 °, and the display characteristics were very good. Therefore, 1.15 ≦ ((no (450) −no (550)) /
It can be seen that in the range of (no (550) -no (650))) ≦ 1.45, coloring is further suppressed and more excellent characteristics can be obtained.

Also, the samples # 41 and # 41 of this embodiment
With respect to 45, although coloring was observed at a viewing angle of 60 ° and a viewing angle of 70 °, no coloring was observed up to a viewing angle of 50 °, and the display characteristics were good and were at a level that could be used.

On the other hand, when the comparative samples # 501 and # 502 were tilted to a viewing angle of 50 °, the coloring was intense and the level was not at a level that could be used.

(Embodiment 5) In Embodiment 5, in the liquid crystal display device shown in FIG.
Optomer AL manufactured by Nippon Synthetic Rubber Co., Ltd. was used as Nos. 1 and 14, and the refractive index anisotropy Δn (550) of this alignment film with respect to light having a wavelength of 550 nm was 0.070, 0.080,
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.
Three liquid crystal display devices (samples # 51 to # 53) were manufactured. The degree of change in the normal light refractive index no and the degree of change in the extraordinary light refractive index ne of each sample were set as shown in Table 5 below.

[0134]

[Table 5]

The retardation plates 2 and 3 used were the same as those in the first embodiment in which the discotic liquid crystal was tilt-aligned.

Further, for comparison, in the liquid crystal display device shown in the liquid crystal display device of FIG. 1, as a liquid crystal material of the liquid crystal layer 8, the refractive index anisotropy Δn with respect to light having a wavelength of 550 nm was used.
Two liquid crystal display devices (comparative samples # 601 and # 602) were produced in the same manner as in the present embodiment except that (550) was set to 0.060 and 0.120.

The samples # 51 to # 53 and the comparative samples # 601 and # 602 are installed in a measurement system including a light receiving element 18, an amplifier 19 and a recording device 20 as shown in FIG. Was done.

In this measuring system, the liquid crystal cell 16 of the liquid crystal display device has the surface 16a on the glass substrate 9 side having the rectangular coordinate axis xy.
It is installed so as to be at the position of the reference plane xy of z. The light receiving element 18 capable of receiving light at a constant three-dimensional 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 at a predetermined distance from the coordinate origin in the direction of (viewing angle).

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

In this measuring system, the sample # 51 of the present embodiment was used.
# 53 and Comparative Samples # 601 and # 602 were installed, and the relationship between the applied voltage 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 fixed angle φ was measured. .

Here, it is assumed that the light receiving elements 18 are 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 (anti-viewing angle direction) and in the left-right direction.

FIGS. 6A to 6C show the measurement results for the samples # 51 to # 53 of this embodiment, and FIG. 7A shows the measurement results for the comparison samples # 601 and # 602.
To (c). 6 (a) to 6 (c) and FIG. 7 (a) to
FIG. 6C is a graph showing light transmittance (transmittance-liquid crystal applied voltage characteristic) with respect to a voltage applied to each liquid crystal display device. FIGS. 6A and 7A are measured from above. 6 (b) and FIG. 7 (b) are the results of measurement from the right direction, and FIG. 6 (c) and FIG. 7 (c).
Is the result of measurement from the left.

In FIGS. 6A to 6C, curves L21, L24 and L27 indicated by alternate long and short dash lines indicate ΔΔ
Sample # 51 using a liquid crystal material of n (550) = 0.070 is shown, and curves L22, L25, and L2 indicated by solid lines are shown.
Reference numeral 8 denotes a sample # 52 using a liquid crystal material of Δn (550) = 0.080 for the liquid crystal layer 8, and a curve L2 indicated by a dotted line
3, L26 and L29 are added to the liquid crystal layer 8 by Δn (550) = 0.
Sample # 53 using a liquid crystal material No. 095 is shown. FIG.
In (a) to (c), curves L30 and L shown by solid lines
32 and L34 are Δn (550) = 0.060 in the liquid crystal layer 8.
Shows the comparative sample # 601 using the liquid crystal material of No. 3, and the curves L31, L33, and L35 indicated by the dotted lines show the liquid crystal layer 8 with Δn
A comparative sample # 602 using a liquid crystal material of (550) = 0.120 is shown.

With respect to the transmittance in the upward direction and the voltage applied to the liquid crystal, the samples # 51 to # 53 of this embodiment show the characteristics shown in FIG.
As shown in L21 to L23 of (a), it was confirmed that the transmittance was sufficiently reduced as the voltage was increased. On the other hand, in comparison sample # 602, L3 in FIG.
As shown in FIG. 1, even if the voltage is increased, the transmittance does not sufficiently decrease, and in the comparative sample # 601, the transmittance temporarily decreases as the voltage increases, as indicated by L30 in FIG. 7A. After that, a reversal phenomenon was seen that rose again.

Similarly, with respect to the transmittance in the right direction and the voltage applied to the liquid crystal, as shown in L24 to L26 in FIG. 6B in the samples # 51 to # 53 of this embodiment, the voltage becomes higher. Accordingly, it was confirmed that the transmittance decreased to almost zero. On the other hand, in comparative sample # 601, FIG.
As shown by L32 in (b), as the voltage increases, the transmittance decreases to nearly zero, but the comparative sample #
In the case of 602, as shown by L33 in FIG. 7B, an inversion phenomenon was observed in which the transmittance once decreased with increasing voltage and then increased again.

Similarly, with respect to the transmittance in the left direction and the voltage applied to the liquid crystal, as shown in L27 to L29 in FIG. 6C in the samples # 51 to # 53 of the present embodiment, the voltage becomes higher. Accordingly, it was confirmed that the transmittance decreased to almost zero. On the other hand, in comparative sample # 601, FIG.
As shown in L34 of (c), as the voltage increases, the transmittance decreases to almost 0, but the comparative sample #
In the case of 602, as shown by L35 in FIG. 7C, an inversion phenomenon was observed in which the transmittance once decreased with increasing voltage and then increased again.

From the above results, as the liquid crystal material of the liquid crystal layer 8, the refractive index anisotropy Δn (55
(0) is set to 0.070, 0.080, and 0.095 (Liquid crystal display device of this embodiment) (samples # 51 to # 53)
As shown in FIGS. 6A to 6C, it can be understood that a liquid crystal display device having a wide viewing angle and excellent viewing angle characteristics without inversion can be realized.

On the other hand, as the liquid crystal material of the liquid crystal layer 8, the refractive index anisotropy Δn (55
In the liquid crystal display device (comparative samples # 601 and # 602) in which (0) is set to 0.060 and 0.120, FIG.
As shown in FIGS. 7 (a) to 7 (c), it can be seen that the level is not a level that can be practically tolerated because an inversion phenomenon occurs or the transmittance at the time of voltage application is not sufficiently reduced.

Further, the dependency of the transmittance-liquid crystal applied voltage characteristic on the tilt angle θ was examined by changing the tilt angle θ of the refractive index ellipsoids of the optical retardation plates 2 and 3.
It was found that the optical compensation effect of the optical retardation plate on the liquid crystal layer was ensured when {≦ θ ≦ 75}, and a liquid crystal display device with a wide viewing angle could be realized.

On the other hand, with an 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 an optical retardation plate having an inclination angle of less than 15 ° or more than 75 °, particularly, the viewing angle in the anti-viewing angle direction tends to be narrow.

Further, 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, it was found that this value was 80 nm.
When the thickness is within the range of 250 nm or less, the optical compensation effect of the optical retardation plate on the liquid crystal layer is assured, 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 obtain sufficient viewing angle characteristics. The second retardation value (na
In the optical retardation plate having −nb) × d smaller than 80 nm or larger than 250 nm, the viewing angle particularly in the left-right direction tended to be narrow.

(Embodiment 6) In this embodiment 6, in the liquid crystal display device shown in FIG.
Optomer AL manufactured by Nippon Synthetic Rubber Co., Ltd. was used as 1 and 14, the cell thickness of the liquid crystal cell 16 was set to 5 μm, and the division ratio of the liquid crystal layer 8 having different alignment states (first region 8a:
Three liquid crystal display devices (samples # 1 to # 3) in which the second regions 8b) were 6: 4, 17: 3, and 19: 1 were manufactured. The degree of change in the normal light refractive index no and the degree of change in the extraordinary light refractive index ne of each sample were set as shown in Table 6 below.

[0154]

[Table 6]

The retardation plates 2 and 3 used were the same as those in Embodiment 1 in which discotic liquid crystals were tilted and aligned.

An experiment for verifying the effect of the ratio of the first area 8a to the second area 8b on the viewing angle characteristics using a measurement system including the light receiving element 18, the amplifier 19, and the recording device 20 shown in FIG. Was done.

In this measurement system, the liquid crystal cell 16 of the liquid crystal display device has the surface 1 on the glass substrate 9 side, as in the fifth embodiment.
6a was set at the position of the reference plane xy of the orthogonal coordinate axis xyz. Further, the light receiving element 18 capable of receiving light at a constant three-dimensional light receiving angle is positioned at a predetermined distance from the coordinate origin in a direction forming an angle φ (viewing angle) with respect to the z direction perpendicular to the surface 16 a of the liquid crystal cell 16. Placed.

At the time of measurement, a 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, and the output of the light receiving element 18 is amplified to a predetermined level by the amplifier 19, and then recorded with a waveform memory, a recorder, and the like. Recorded by device 20.

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

Here, it is assumed that the light receiving elements 18 are arranged so that the angle φ is 30 °, and that the x direction is on the lower side of the screen and the y direction is on the left side of the screen. Positions are upward (anti-viewing angle direction), downward (normal viewing angle direction),
The measurement was carried out while changing each to the left and right.

The measurement results at this time are shown in FIGS.
Shown in FIGS. 8A to 8C are graphs showing light transmittance (transmittance-liquid crystal applied voltage characteristics) with respect to a voltage applied to each liquid crystal display device. FIG. 4
FIG. 8 (b) shows the measurement result of sample # 2 having a division ratio of 17: 3, and FIG. 8 (c) shows the measurement result of sample # 1.
Shows the measurement result of Sample # 3 having a division ratio of 19: 1.

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

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

In the downward measurement, the transmittance was kept constant at a low value of about 7% in the ON state, and no inversion phenomenon was observed. In the upward measurement, 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 reduced.

The sample # 1 shown in FIG.
For 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. Begin to appear, and the tendency increases as the division ratio increases. On the other hand, as shown in FIG.
In the 9: 1 sample # 3, the curve L2 (downward) tends to approach the curve L1 (z-axis direction) in the halftone display area and in the ON state, and the tendency increases as the division ratio decreases. Thereby, the phenomenon that the black gradation of the display image is crushed in the downward direction (the direction of the normal viewing angle) is suppressed.

As a result of further investigation, it was found that the division ratio was 7: 3.
In the range of ９9: 1, the above-mentioned 17: 3 sample # 3
It was confirmed that good viewing angle characteristics were balanced in the downward direction and the upward direction as shown in FIG.

Further, for comparison, a comparative sample # 101 in which the first region 8a: the second region 8b of the liquid crystal layer 8 was set to 1: 1 was prepared and installed in the measurement system shown in FIG. Dependency positive was measured. FIG. 9 shows the result.

In FIG. 9, a curve L1 indicated by a solid line
1 is the z-axis direction, curve L12 indicated by a broken line is downward, curve L13 indicated by a dotted line is rightward, and curve L indicated by a dashed line
14 indicates the characteristic in the upward direction, and the curve L15 indicated by the two-dot chain line indicates 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 viewing angle characteristics. However, in the vertical direction, the transmittance is not sufficiently reduced in the ON state, and it can be seen that there is a viewing angle dependency in the vertical direction.

Here, two liquid crystal display elements 1 are provided on both sides.
Although the two optical retardation plates 2 and 3 are arranged, the viewing angle characteristics as described above 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 the optical retardation plates is one, the viewing angle characteristics in the vertical direction are balanced and improved, but the viewing angle characteristics in the horizontal direction may be 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-right direction are also symmetric, so that the viewing angle characteristics are improved in both the upper, lower, left and right directions.
Furthermore, when two optical retardation plates are arranged, both may be arranged so as to overlap one side of the liquid crystal display element 1. In addition, 3
It is also possible to use more than one retardation plate.

[0172]

As described above in detail, according to the present invention, the liquid crystal display element in which the liquid crystal layer is divided into a plurality of regions having different alignment states in each pixel at different ratios, and the refractive index ellipsoid are inclined. By combining with the optical phase difference element having negative uniaxiality, the viewing angle in the left-right direction (3 o'clock 9 o'clock direction) of the display screen is increased, and the vertical direction (6 o'clock 12 o'clock
The viewing angle can be increased in the (time direction).
In particular, the transmittance at the time of applying a voltage can be sufficiently reduced in the upward direction (opposite viewing angle direction), and the collapse of black gradation at the time of applying a voltage can be reduced in the downward direction (direction of normal viewing angle).

In addition, the normal refractive index n of the liquid crystal material
By optimizing at least one of the degree of change of o with respect to the wavelength and the extraordinary light refractive index ne, it is possible to suppress the coloring of the display screen when the viewing angle is lowered or halftone display is performed. 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, claim 2, claim 3, and claim 5
According to the present invention, the extraordinary light refractive index ne (450) of the liquid crystal material with respect to light having a wavelength of 450 nm and a wavelength of 550 n
m, an extraordinary light refractive index ne (550) and a wavelength of 6
An extraordinary light refractive index ne (650) for 50 nm light;
Normal light refractive index no (45 for light of wavelength 450 nm)
0), normal light refractive index no for light having a wavelength of 550 nm
(550) and the normal light refractive index no (650) for light having a wavelength of 650 nm are represented by ((no (450) -no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
≧ 1.00, by optimizing at least one of the degree of change of the normal light refractive index no of the liquid crystal material with respect to the wavelength and the extraordinary light refractive index ne, the viewing angle can be reduced to 50 °. It is possible to realize a liquid crystal display device having display characteristics excellent in visibility without coloring.

In particular, according to the present invention of claims 4 and 6, by optimizing at least one of the degree of change of the normal refractive index no of the liquid crystal material with respect to the wavelength and the extraordinary refractive index ne. In addition, a liquid crystal display device having display characteristics excellent in visibility without coloring even when the viewing angle is reduced to 70 ° can be realized.

Furthermore, claims 7, 8 and 1
0 according to the present invention, the wavelength of the liquid crystal material is 450 nm.
Extraordinary refractive index ne (450) for light of wavelength 550
extraordinary light refractive index ne (550) for light of nm and extraordinary light refractive index ne (650) for light of wavelength 650 nm
And the normal light refractive index no (4
50), normal light refractive index no for light having a wavelength of 550 nm
(550) and the normal light refractive index no (650) for light having a wavelength of 650 nm are represented by ((no (450) -no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
In the case where the relationship of <1.00 is satisfied, by optimizing at least one of the degree of change of the normal refractive index no of the liquid crystal material with respect to the wavelength and the extraordinary refractive index ne, the viewing angle can be reduced to 50 °. It is possible to realize a liquid crystal display device having display characteristics excellent in visibility without coloring.

In particular, according to the ninth and eleventh aspects of the present invention, by optimizing at least one of the degree of change of the normal refractive index no of the liquid crystal material with respect to the wavelength and the extraordinary refractive index ne. In addition, a liquid crystal display device having display characteristics excellent in visibility without coloring even when the viewing angle is reduced to 70 ° can be realized.

According to the twelfth aspect of the present invention, the refractive index anisotropy Δn of the liquid crystal material with respect to light having a wavelength of 550 nm.
By setting (550) in the range of 0.060 <Δn (550) <0.120, the transmittance at the time of applying a voltage can be sufficiently reduced, and the inversion phenomenon and the reduction of the contrast ratio can be prevented.

In particular, according to 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 set in the range of 0.070 ≦ Δn (550) ≦ 0.095. By doing so, it is possible to further reduce the transmittance at the time of applying a voltage and to reliably prevent the inversion phenomenon and the decrease in the contrast ratio.

According to the fourteenth aspect of the present invention, the tilt angle of the refractive index ellipsoid in the optical phase difference element is set in the range of 15 ° or more and 75 ° or less, so that the optical phase difference element has an optical property with respect to the liquid crystal layer. Since the objective compensation function can be reliably obtained, a liquid crystal display device having a wide viewing angle and high contrast display characteristics can be realized.

According to the fifteenth aspect of the present invention, the product (na−nb) × d of the difference between the main refractive indices na and nb of the optical phase difference element and the thickness d is set in the range from 80 nm to 250 nm. By setting, the optical compensation function for the liquid crystal layer of the optical retardation element can be reliably obtained.
A liquid crystal display device having a wide viewing angle and high contrast display characteristics can be realized.

According to the sixteenth aspect of the present invention, the orientation processing direction of the alignment film and the inclination directions of the main refractive indices nb and nc of the optical retardation element are opposite to each other in the largest region in the pixel. By arranging the liquid crystal display element and the optical retardation element, the direction in which the liquid crystal molecules rise when a voltage is applied and the inclination direction of the refractive index ellipsoid of the optical retardation plate are opposite to each other. Thus, the optical anisotropy accompanying 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, according to the seventeenth aspect of the present invention, in the smallest region in the pixel, the alignment processing direction of the alignment film and the inclination directions of the main refractive indexes nb and nc of the optical retardation element are the same. By arranging the liquid crystal display element and the optical retardation element in such a manner, the smallest area in the pixel has a viewing angle characteristic opposite to the largest area in the pixel, and the black gradation in the largest area is obtained by adding this component. And the vertical viewing angle can be increased by reducing the crushing.

Furthermore, according to the eighteenth aspect of the present invention, the ratio of the first region and the second region of the liquid crystal layer in each pixel is set to be 6: 4 or more and 19: 1 or less, so that the visual field in the left-right direction is obtained. Along with the enlargement of the angle, it is possible to improve the contrast in the upward direction (the opposite viewing angle direction) and suppress the black gradation from being lost when applying the voltage in the downward direction (the normal viewing angle direction). Thus, a liquid crystal display device having a wide viewing angle, high contrast, and excellent visibility can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to 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.

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.

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 dependency of the liquid crystal display device.

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

FIG. 7 is a graph showing transmittance-liquid crystal applied voltage characteristics 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 sixth 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]

 REFERENCE SIGNS LIST 1 liquid crystal display element 2, 3 optical retardation plate 4, 5 polarizing plate 6, 7 electrode substrate 8 liquid crystal layer 8 a first region 8 b second region 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

Claims (18)

[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 a surface of at least one of the substrates 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 each including a polarizer, 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 crystal in each pixel. In the liquid crystal display device in which each region occupies a different area in a pixel, the three main refractive indices n of the refractive index ellipsoid of the optical phase difference element are provided.
a, nb, and nc have a relationship of na = nc> nb, and the direction of the main refractive index nb is clockwise from the normal direction of the surface with the main refractive index na substantially parallel to the surface of the optical phase difference element as an axis. And the direction of the main refractive index nc is inclined clockwise or counterclockwise from a direction substantially parallel to the surface, and the normal refractive index of the liquid crystal material in the liquid crystal layer. A liquid crystal display device in which at least one of the degree of change with respect to the wavelength of no and the degree of change with respect to the wavelength of the extraordinary light refractive index ne is set within a range in which screen coloring depending on the viewing angle does not occur. 2. 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 of the liquid crystal material.
m, the extraordinary light refractive index ne (650), and the wavelength 4
Normal light refractive index no (450) for light of 50 nm, normal light refractive index no (550) for light of wavelength 550 nm
And the normal light refractive index no (6
(50) and ((no (450) −no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
2. The liquid crystal display device according to claim 1, wherein a relationship of ≧ 1.00 is satisfied. 3. 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 of the liquid crystal material.
The degree of change of the extraordinary light refractive index ne (650) with respect to light of m is 1.70 ≦ ((ne (450) -ne (550)) /
The liquid crystal display device according to claim 1, wherein (ne (550) −ne (650))) ≦ 2.30. 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 650n of the liquid crystal material.
The degree of change of the extraordinary light refractive index ne (650) with respect to light of m is 1.85 ≦ ((ne (450) −ne (550)) /
4. The liquid crystal display device according to claim 3, wherein (ne (550) −ne (650))) ≦ 2.10. 5. 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 n of the liquid crystal material.
The degree of change of the normal light refractive index no (650) with respect to light of m is 1.65 ≦ ((no (450) −no (550)) /
The liquid crystal display device according to claim 1, wherein (no (550) −no (650))) ≦ 2.40. 6. 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 n of the liquid crystal material.
The degree of change of the normal light refractive index no (650) with respect to light of m is 1.85 ≦ ((no (450) −no (550)) /
The liquid crystal display device according to claim 5, wherein (no (550) −no (650))) ≦ 2.20. 7. 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 of the liquid crystal material.
m, the extraordinary light refractive index ne (650), and the wavelength 4
Normal light refractive index no (450) for light of 50 nm, normal light refractive index no (550) for light of wavelength 550 nm
And the normal light refractive index no (6
(50) and ((no (450) −no (550)) / (no (55)
0) -no (650))) / ((ne (450) -ne
(550)) / (ne (550) -ne (650)))
2. The liquid crystal display device according to claim 1, having a relationship of <1.00. 8. An extraordinary light 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 of the liquid crystal material.
The degree of change of the extraordinary light refractive index ne (650) with respect to light of m is 1.20 ≦ ((ne (450) −ne (550)) /
The liquid crystal display device according to claim 1, wherein (ne (550) −ne (650))) ≦ 1.70. 9. 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 650n of the liquid crystal material.
The degree of change of the extraordinary light refractive index ne (650) with respect to light of m is 1.35 ≦ ((ne (450) −ne (550)) /
The liquid crystal display device according to claim 8, wherein (ne (550) −ne (650))) ≦ 1.60. 10. 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 650 of the liquid crystal material.
The degree of change of the normal light refractive index no (650) with respect to light of nm is 1.00 ≦ ((no (450) −no (550)) /
The liquid crystal display device according to claim 1, wherein (no (550) −no (650))) ≦ 1.65. 11. 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 650 of the liquid crystal material.
The degree of change of the normal light refractive index no (650) with respect to light of nm is 1.15 ≦ ((no (450) −no (550)) /
The liquid crystal display device according to claim 10, wherein (no (550) −no (650))) ≦ 1.45. 12. The liquid crystal material according to claim 1, wherein said liquid crystal material has a refractive index anisotropy Δn (550) of 0.060 <Δn (550) <0.120 with respect to light having a wavelength of 550 nm. 12. The liquid crystal display device according to any one of 11. 13. The liquid crystal material according to claim 12, wherein a refractive index anisotropy Δn (550) of the liquid crystal material with respect to light having a wavelength of 550 nm is set in a range of 0.070 ≦ Δn (550) ≦ 0.095. Liquid crystal display. 14. The liquid crystal display device according to claim 1, wherein an inclination angle of the refractive index ellipsoid in the optical retardation element is set in a range from 15 ° to 75 °. 15. The product (na) of the difference between the main refractive indices na and nb of the optical phase difference element and the thickness d of the optical phase difference element.
The liquid crystal display device according to claim 1, wherein −nb) × d is set in a range from 80 nm to 250 nm. 16. In the largest region in a pixel among the plurality of regions in which the liquid crystal has different alignment states, the orientation processing direction of the alignment film and the inclination directions of the main refractive indexes nb and nc of the optical phase difference element are determined. 2. The liquid crystal display element and the optical phase difference element are arranged so that the directions are opposite to each other.
The liquid crystal display device according to claim 15. 17. The orientation processing direction of the orientation film and the main refractive indices nb and nb of the optical phase difference element in the smallest region in the pixel among the plurality of regions in which the orientation state of the liquid crystal is different.
17. The liquid crystal display device according to claim 16, wherein the liquid crystal display element and the optical phase difference element are arranged so that the inclination direction of c is the same. 18. 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 in a range from 6: 4 to 19: 1. The liquid crystal display device according to claim 1.