JP2003107477A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the visual angle characteristic in a direction desired by a user by freely arranging the axes of polarization of two polarizing plates fixed heretofore in a 45 deg. direction of a liquid crystal display device of an OCB system regardless of the optical axis direction of a liquid crystal layer bendingly aligned. SOLUTION: The polarizing plates 206 and 207 and λ/4 wavelength plates 208 and 209 are attached to first and second substrates 202 and 203 of a liquid crystal panel subjected to the bend orientation by including the transmission axes of the polarizing plates and the optical axes of the λ/4 wavelength plates in such a manner that the circularly polarized light rays reverse from each other are obtained. At this time, incident light is converted to the circularly polarized light and is made incident on the liquid crystal layer and does not therefore depend in the polarizing plate axial directions of the polarizing plates and the maximum value of the intensity of the emitted light is constant. Thus, the optical axes of the liquid crystal layer can be arranged in free directions without receiving restrictions except that the transmission axes of the first and second polarizing plates are interested orthogonally with each other while the optical axes are held fixed in the horizontal direction desirable for the stability of the bend orientation, and the visual angle of the desired direction concentration can be made wider.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-sized and high-definition moving image-capable liquid crystal display device having a wide viewing angle and high-speed response.

[0002]

2. Description of the Related Art Twisted nematic, which has been widely used in the past, is hereinafter referred to as "TN".
In a liquid crystal display device of a By changing the, the “white” display state is gradually changed to the “black” display state.

However, in the TN type liquid crystal display device,
Due to the behavior peculiar to liquid crystal molecules when the voltage is applied, there is a problem that the viewing angle is narrow. The problem that the viewing angle is narrow is particularly remarkable in the rising direction of liquid crystal molecules in halftone display.

Therefore, for example, Japanese Patent Laid-Open No. 4-26152
No. 2, JP-A-6-43461 or JP-A-1.
0-333180 proposes a method for improving the viewing angle characteristics of a liquid crystal display device.

According to these methods, a homeotropically aligned liquid crystal cell is prepared, the liquid crystal cell is sandwiched between two polarizing plates arranged so that their transmission axes are orthogonal to each other, and a common electrode having an opening is formed. By using it, an oblique electric field is generated in each pixel. Due to this oblique electric field,
Each pixel has two or more liquid crystal domains to improve the viewing angle characteristics.

In the method proposed by Japanese Patent Laid-Open No. 4-261522, particularly, high contrast is realized by controlling the direction in which the liquid crystal tilts when a voltage is applied.

Further, the method proposed in Japanese Patent Laid-Open No. 6-43461 uses an optical compensator as needed to improve the viewing angle characteristics of black.

Further, in the method proposed by Japanese Patent Laid-Open No. 6-43461, not only in a homeotropically aligned liquid crystal cell but also in a TN aligned cell, each pixel is divided into two or more domains by an oblique electric field. It is divided to improve the viewing angle characteristics.

Further, in the method proposed by Japanese Patent Laid-Open No. 10-333180, the effect of the oblique electric field generated by the common electrode having the opening is reduced by the thin film transistor,
In order to prevent being affected by the electric field from the gate line and the drain line, the thin film transistor, the gate line,
The drain line is arranged below the display electrode.

Further, in Japanese Patent Application Laid-Open No. 10-20323, in a liquid crystal display device in which two or more kinds of minute regions coexist in a liquid crystal layer, an opening is formed in one substrate and a second electrode is formed in the opening. There is described a method in which an oblique electric field is generated by applying a voltage to the second electrode to divide the alignment direction of the liquid crystal in the pixel to widen the viewing angle. This method is mainly carried out for TN-oriented cells.

Japanese Unexamined Patent Publication (Kokai) No. 5-113561 discloses an optically negative liquid crystal display device having a vertically-aligned liquid crystal display device, which has a negative viewing angle to cancel the angular dependence of the birefringence index of the liquid crystal when no voltage is applied. It is described that a birefringence compensating plate and an optically positive and negative quarter-wave plate for ensuring brightness are used.

Further, Japanese Patent No. 2947350 describes that projections or electrode slits are provided on the upper and lower substrates in order to divide the vertically aligned liquid crystal when a voltage is applied, and that at least one is a projection. There is.

Further, in Japanese Laid-Open Patent Publication No. 5-505247, in order to rotate liquid crystal molecules while keeping them in the horizontal direction with the substrate, two electrodes are provided on one of the substrates, and a voltage is applied between the two electrodes. Is applied to generate an electric field in the horizontal direction with respect to the substrate. In-Plane Switch
An ing (IPS) type liquid crystal display device has been proposed. In this IPS type liquid crystal display device, the long axis of the liquid crystal molecules does not rise with respect to the substrate when a voltage is applied. Therefore, there is a feature that the change in birefringence of the liquid crystal when the viewing angle direction is changed is small and the viewing angle is wide.

Furthermore, Journal of Appl
ied Physics, Vol. 45, No. 12
In (1974) 5466 and Japanese Patent Laid-Open No. 10-186351, in addition to the above-mentioned IPS mode, a liquid crystal having a positive dielectric anisotropy is homeotropically aligned to generate a horizontal electric field on the substrate. Then, a method of tilting the liquid crystal molecules in the horizontal direction with respect to the substrate is described. According to this method, the homeotropically aligned liquid crystal molecules are divided into two or more regions having different tilt directions due to the direction of the electric field, and as a result, a liquid crystal display device having a wide viewing angle can be obtained.

Further, in Japanese Unexamined Patent Publication No. 10-186330, a square wall is formed by using a photosensitive material, a pixel is formed by using this structure as a basic unit, and a dielectric constant anisotropy is negative when a voltage is applied. There has been proposed a method of dividing the liquid crystal in each pixel and defeating it.

However, both the conventional TN system and the above means have a problem that the response speed is slow. A liquid crystal display device using a nematic liquid crystal generally has a slow response speed. The maximum response time between gradations is about 100 ms, which is not compatible with high-speed moving image display.

Therefore, a liquid crystal display system having a wide viewing angle and a high speed response has been conventionally required.

For example, Y. Yamaguchi, et
al. , SID'93 Digest, pp277-2
80, or in JP-A-7-84254, O
physically Compensated Bire
It is described that the fringence (hereinafter abbreviated as "OCB") system has a wide viewing angle and a high-speed response. A liquid crystal cell used in the OCB system has a bend alignment and is also called a π cell. π
The fact that the cell exhibits a high-speed response is described in, for example, Japanese Patent Laid-Open No.
It is also described in Japanese Patent No. 42316.

FIG. 8 shows an example of the basic structure of an OCB type liquid crystal display device.

The liquid crystal display device shown in FIG. 8 has two glass substrates 802 and 803 which are stacked so that the rubbing directions are parallel to each other, and a liquid crystal layer in a bend alignment state which is sandwiched between the glass substrates 802 and 803. 801, two birefringence compensation plates 804 and 805 sandwiching each of the two glass substrates 802 and 803 from the outside, and a birefringence compensation plate 80.
Two polarizing plates 8 sandwiching each of 4, 805 from the outside
It consists of 06 and 807.

The birefringence compensating plates 804 and 805 are birefringence compensating plates using discotic liquid crystal, which are optically negative and have a structure in which the inclination of the principal axis in the layer changes.

Due to its structure, the bend orientation is always self-compensating in the rubbing direction and exhibits an optically symmetrical characteristic.

In the active matrix driving for performing the space division type full color display, one pixel has a vertically long shape with a length to width ratio of about 3: 1. In such a case, considering the stability of the bend alignment, it is advantageous to set the rubbing direction to the short side direction of the pixel, that is, the horizontal direction.

In consideration of the viewing angle characteristics of the display, the rubbing direction having the self-compensating property is arranged in the horizontal direction.

The orientation change of the liquid crystal molecules in the bend orientation becomes maximum in the plane parallel to the optical axis direction, that is, the orientation direction of the liquid crystal molecules at the interface and perpendicular to the substrate. Therefore, when the liquid crystal layer is sandwiched by two polarizing plates whose transmission axes are orthogonal to each other, the maximum birefringence occurs when the optical axis direction is arranged at 45 ° with respect to the transmission axis of the polarizing plate. Becomes
When the rubbing direction is fixed in the horizontal direction, the transmission axes of the two polarizing plates 806 and 807 are necessarily in the 45 ° direction.

There are two driving methods of the OCB method: normally black driving for displaying black on the low voltage side and normally white driving for displaying black on the high voltage side. In the Marie Black drive, light leakage due to wavelength dispersion is large, and it is difficult to obtain sufficient contrast.

Therefore, in Japanese Unexamined Patent Publication No. 8-327822, the above problem is solved by performing normally white driving using two negative birefringence compensating plates 804 and 805 as shown in FIG. Has been resolved. That is,
On the high voltage side, most liquid crystal molecules are aligned vertically except near the interface. Wide viewing angle characteristics are obtained by compensating the residual birefringence at both interfaces with the two negative birefringence compensating plates 804 and 805, respectively.

[0028]

However, in the OCB system of the conventional structure as described above, in the direction of 45 °,
That is, the viewing angle characteristics of the polarizing plate in the transmission axis direction are improved.

Not only in the OCB system, but in the black display of a liquid crystal display device which generally utilizes birefringence, the viewing angle dependence of the polarizing plate itself provides good viewing angle characteristics in the transmission axis direction.

Therefore, it is desirable that the transmission axes of the two polarizing plates can be arranged in the direction desired by the user. However, in the current configuration, in order to move the transmission axes of the two polarizing plates, the optical axes of the liquid crystal layers are simultaneously adjusted. It is necessary to move in the axial direction. However,
It is not preferable to move the optical axis direction of the liquid crystal layer from the horizontal direction in terms of stability of bend alignment.

As described above, the conventional OCB type liquid crystal display device has a problem that the transmission axis of the polarizing plate is not freely arranged and the wide viewing angle characteristic cannot be fully utilized.

Further, in the conventional OCB type liquid crystal display device, accurate control of the alignment direction of the liquid crystal is required to obtain high brightness and high contrast. That is, there is a problem that the process margin in the manufacturing process is low, that is, the brightness and the contrast are lowered due to the deviation of the alignment direction.

The present invention has been made in view of the problems in the conventional liquid crystal display device as described above, and in the OCB type liquid crystal display device, it is controlled in the direction of the optical axis of the bend-aligned liquid crystal layer. The degree of freedom in arranging the transmission axis of the polarizing plate can be ensured without
An object of the present invention is to provide a liquid crystal display device that can obtain a desired viewing angle characteristic.

The present invention further provides a liquid crystal display device in which the optical characteristics are not significantly deteriorated even if the alignment direction of the liquid crystal is slightly deviated, and thus the process margin in the manufacturing process can be increased. To aim.

[0035]

To achieve this object, the present invention is directed to a first substrate, a second substrate, a first substrate and a second substrate, and a bend alignment. And the first liquid crystal layer disposed on the outer side of the first substrate.
/ 4 wave plate and the second 1 arranged outside the second substrate.
Quarter wave plate, at least one first polarizing plate arranged outside the first quarter wave plate, and at least one second polarizing plate arranged outside the second quarter wave plate. A polarizing plate,
Provided is a liquid crystal display device comprising:

According to the present invention, by converting the light incident on the liquid crystal layer into circularly polarized light, it becomes possible to set the transmission axis of the polarizing plate in a desired direction, and the viewing angle characteristic in an arbitrary direction is maximized. Can be good.

For example, in the liquid crystal display device according to the present invention, the first quarter-wave plate and the first polarizing plate are set so as to have opposite circular polarization, and the second quarter-wave plate is set. The plate and the second polarizing plate are set so as to be circularly polarized light opposite to each other, and the optical axis of the first quarter-wave plate and the transmission axis of the first polarizing plate are inclined by 45 degrees with respect to each other. The optical axis of the second quarter-wave plate and the transmission axis of the second polarizing plate are tilted by 45 degrees with respect to each other.

The optical axis is 45 with respect to the transmission axis of the first polarizing plate.
When the first quarter-wave plate is arranged so as to be inclined, the linearly polarized light transmitted through the first polarizing plate is converted into circularly polarized light by the first quarter-wave plate. The first one seen from the incident direction
The optical axis of the quarter wave plate is 45 ° to the right from the transmission axis of the first polarizing plate.
If it is tilted in the direction of, it becomes right circularly polarized light, and if it tilts in the direction of 45 ° left, it becomes left circularly polarized light.

For example, the optical axis of the second quarter-wave plate arranged on the emission side is arranged parallel to the optical axis of the first quarter-wave plate, and the transmission axis of the second polarizing plate is the first. It is assumed that the polarizing plate of No. 1 is arranged so as to be orthogonal to the transmission axis. If the total retardation of the birefringent medium laminated between the two quarter-wave plates is π, the right-hand circularly polarized light is emitted as left-handed circularly polarized light, and the second quarter-wave plate orthogonally crosses the incident linearly polarized light. Is converted to linearly polarized light. At this time, the brightness of the transmitted light becomes maximum. Therefore, even if the optical axis of the liquid crystal layer is arranged in any direction, or even if the initial alignment direction near the interface between the liquid crystal layer and the first or second substrate is deviated, the maximum transmitted light intensity can be obtained. . If the total retardation is 0, the right circularly polarized light is emitted as it is, and is converted into the linearly polarized light parallel to the incident linearly polarized light by the second quarter wave plate. At this time, the transmitted light intensity is zero.

By applying the above, the optical axis of the liquid crystal layer is arranged in the horizontal direction to enhance the stability of the bend alignment, and
The transmission axis of the second polarizing plate can be arranged in any direction without being restricted by making them orthogonal to each other, and widens the viewing angle in a desired direction, for example, the horizontal and vertical directions. It will be possible.

As described above, according to the liquid crystal display device of the present invention, it is possible to use the liquid crystal display device by adding two quarter-wave plates to the structure of the conventional liquid crystal display device without largely changing the manufacturing process. It is possible to obtain a desired viewing angle characteristic of the person.

However, the quarter-wave plate is a kind of optically active uniaxial medium, and the birefringence of the quarter-wave plate itself may affect the compensation of the birefringence of the liquid crystal layer. Therefore, in order to compensate the birefringence of the quarter-wave plate, a pair of 1's
It is desirable that one of the / 4 wave plates has an optically positive activity and the other has an optically negative activity.

Alternatively, when one of the quarter-wave plates is optically positive, an optically negative birefringence compensating plate that compensates for the birefringence of the liquid crystal layer and the birefringence of the quarter-wave plate at the same time is used. You may add.

Although there is a problem of wavelength dispersion in the quarter-wave plate, norbornene-based transparent heat-resistant resin (JSR Corporation, trade name Arton) having a small wavelength dispersion is used as the material, or A wide band can be achieved by a method such as a laminated structure of a four-wave plate and a half-wave plate.

In this case, the constituent elements are made of optically negative materials so that the retardation of the liquid crystal layer, the quarter-wave plate and the half-wave plate becomes zero as a whole. An optical compensation layer for compensation may be added. Further, a biaxial compensating plate may be used optically, and one or more compensating plates may perform some or all of the functions performed by a plurality of compensating plates.

Further, in the liquid crystal display device according to the present invention, the first liquid crystal display device is arranged between the first substrate and the first quarter wave plate.
And a second birefringence compensating plate disposed between the second substrate and the second quarter-wave plate, the first and second birefringence compensating plates Both have a structure in which the constituent elements are optically negative and the inclination of the principal axis in the layer changes, and the birefringence of the liquid crystal layer is compensated by the first and second birefringence compensating plates. It is preferable that

The liquid crystal display device according to the present invention has a second
Further comprising a birefringence compensating plate disposed between the substrate of the second component and the second quarter-wave plate, the birefringence compensating plate having a component that is optically negative, and a principal axis in the layer. Preferably, the birefringence compensator compensates for the birefringence of the liquid crystal layer and the birefringence of the first quarter-wave plate.

Further, the liquid crystal display device according to the present invention is the second
Further comprises an optically positive uniaxial birefringence compensating plate or a biaxial birefringence compensating plate disposed between the substrate and the second quarter-wave plate. It is preferable that the birefringence of the liquid crystal layer is compensated by a compensating plate or a biaxial birefringence compensating plate.

Further, in the liquid crystal display device according to the present invention, the plurality of scanning signal electrodes, the plurality of video signal electrodes intersecting the scanning signal electrodes in a matrix, the scanning signal electrodes, and the scanning signal electrodes are formed on the first substrate. A plurality of thin film transistors formed corresponding to each intersection of the video signal electrodes is formed, and one pixel is formed in each region surrounded by the scanning signal electrode and the video signal electrode, and on the first substrate, Further, it is preferable that a pixel electrode connected to a thin film transistor corresponding to each pixel is formed, and a common electrode that gives a reference potential across a plurality of pixels is formed on the second substrate.

An interlayer insulating film for separating the pixel electrode from the scanning signal electrode, the video signal electrode and the thin film transistor is preferably formed on the first substrate.

A color filter layer is formed on the scan electrodes, the video signal electrodes and the thin film transistors on the first substrate, and the pixel electrodes and the scan signal electrodes, the video signal electrodes and the thin film transistors are color filter layers. It is preferable that they are separated via.

The liquid crystal layer preferably contains an ultraviolet polymerizable monomer for stabilizing the bend alignment, for example, a liquid crystal diacrylate monomer.

It is preferable that the orientation of the liquid crystal near the interface between the first substrate and the second substrate and the liquid crystal layer is substantially parallel to the short side direction of the pixel.

Further, the present invention provides a method of manufacturing the above liquid crystal display device. This method is characterized by including a process of controlling the alignment of liquid crystal molecules of the liquid crystal layer by a photo-alignment technique.

[0055]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below.

(First Embodiment) FIG. 1 is an exploded configuration diagram of a liquid crystal display device according to a first embodiment of the present invention.

The liquid crystal display device according to this embodiment includes a first substrate 102, a second substrate 103, and a first substrate 102.
The liquid crystal layer 101 sandwiched between the first substrate 102 and the second substrate 103 and having a bend orientation, the first quarter-wave plate 108 disposed outside the first substrate 102, and the first first wavelength plate 108. A first polarizing plate 106 arranged outside the quarter wave plate 108;
A second quarter-wave plate 109 arranged outside the second substrate 103 and a second polarizing plate 107 arranged outside the second quarter-wave plate 109 are provided.

The liquid crystal display device according to this embodiment operates as follows.

Incident light that has passed through the first polarizing plate 106 is converted into linearly polarized light by the first polarizing plate 106. The optical axis of the first quarter-wave plate 108 is arranged in the direction of 45 ° to the right from the transmission axis of the polarizer when viewed from the incident direction. Therefore,
Incident light is converted from linearly polarized light to right circularly polarized light.

When the retardation of the liquid crystal layer 101 in the bend orientation is π, the incident right circularly polarized light is emitted as left circularly polarized light.

After that, by the second quarter wave plate 109 whose optical axis is arranged in parallel with the first quarter wave plate 108,
It is converted into linearly polarized light that is orthogonal to the incident linearly polarized light.
That is, this is equivalent to the incident linearly polarized light being rotated by 90 °.

Thus, the linearly polarized light emitted from the second quarter-wave plate 109 is parallel to the transmission axis of the second polarizing plate 107, so that the brightness becomes maximum.

From the above, in the liquid crystal display device according to the present embodiment, the maximum value of the emitted light intensity is constant no matter which direction the optical axis of the liquid crystal layer 101 is arranged.

Further, since the liquid crystal of the liquid crystal layer 101 has a bend alignment, even if an ON or OFF response speed is added, it takes 7 ms.
And a very fast response is obtained.

(Second Embodiment) FIG. 2 is an exploded configuration diagram of a liquid crystal display device according to a second embodiment of the present invention.

The liquid crystal display device according to the present embodiment has a first substrate 202, a second substrate 203, and a first substrate 202.
And the second substrate 203 sandwiched between the liquid crystal layer 201 and the second substrate 203, and the first birefringence compensating plate 204 disposed outside the first substrate 202 and the first birefringence. The first quarter-wave plate 20 arranged outside the compensation plate 204
8, a first polarizing plate 206 arranged outside the first quarter-wave plate 208, a second birefringence compensating plate 205 arranged outside the second substrate 203, and a second A second quarter-wave plate 209 arranged outside the birefringence compensating plate 205.
A second quarter wave plate 209 disposed outside the second quarter wave plate 209.
Polarizing plate 207 of the above.

The first and second birefringence compensating plates 204, 20
Each of the constituent elements of 5 is optically negative, and in the first and second birefringence compensating plates 204 and 205, the discotic liquid crystal is tilted within the layer. The first and second birefringence compensating plates 204 and 205 compensate the birefringence of the liquid crystal layer 201 in the black display state.

The liquid crystal display device according to the present embodiment is different from the liquid crystal display device according to the first embodiment in that it is provided with the first and second birefringence compensation plates 204 and 205.

The liquid crystal display device according to this embodiment operates as follows.

Incident light that has passed through the first polarizing plate 206 is converted into linearly polarized light by the first polarizing plate 206. The optical axis of the first quarter-wave plate 208 is arranged in the direction of 45 ° to the right from the transmission axis of the polarizer when viewed from the incident direction. Therefore, the incident light is converted from linearly polarized light to right circularly polarized light.

In the white state, the retardation becomes π as a result of compensating the liquid crystal layer 201 in the bend alignment by the first and second birefringence compensating plates 204 and 205 using the discotic liquid crystal. Therefore, the incident right circularly polarized light is emitted from the second birefringence compensating plate 205 as left circularly polarized light. In this case, the second quarter-wave plate 209 converts the left circularly polarized light into linearly polarized light that is orthogonal to the incident linearly polarized light. That is, this is equivalent to the incident linearly polarized light being rotated by 90 °.

As described above, the linearly polarized light emitted from the second quarter-wave plate 209 is parallel to the transmission axis of the second polarizing plate 207, and thus has the maximum brightness.

In the black state, the birefringence of the liquid crystal layer 201 having the bend alignment is compensated by the first and second birefringence compensating plates 204 and 205 using the discotic liquid crystal, and the retardation becomes zero. Therefore, the incident right circularly polarized light is emitted from the second birefringence compensating plate 205 as it is as right circularly polarized light. Then, the first quarter-wave plate 208
The second quarter-wave plate 209, whose optical axis is arranged in parallel with, converts it into the same linearly polarized light as the incident linearly polarized light.

As described above, the outgoing linearly polarized light is blocked by the second polarizing plate 207 whose transmission axis is orthogonal to the transmission axis of the first polarizing plate 206.

As described above, normally white driving becomes possible. The transmittance in the white state does not depend on the optical axis direction of the liquid crystal layer 201 and is always constant.

Further, since the black state is compensated, an image with good visibility can be obtained regardless of the viewing angle of the display device.
A display device with a very wide viewing angle can be obtained.

Further, reflecting that the liquid crystal of the liquid crystal layer 201 is in the bend orientation, a very high speed response can be obtained as compared with other liquid crystal modes.

(Third Embodiment) FIG. 3 is an exploded configuration diagram of a liquid crystal display device according to a third embodiment of the present invention.

The liquid crystal display device according to the present embodiment has a first substrate 302, a second substrate 303, and a first substrate 302.
And the second substrate 303 are sandwiched between the liquid crystal layer 301 and the first substrate 202, and the first quarter-wave plate 308 is disposed outside the first substrate 202. A first polarizing plate 306 disposed outside the quarter wave plate 308;
Birefringence compensating plate 30 arranged outside second substrate 303
5 and a second 1 arranged outside the birefringence compensating plate 305.
The quarter-wave plate 309 and the second polarizing plate 307 arranged outside the second quarter-wave plate 309 are provided.

In the birefringence compensation plate 305, the discotic liquid crystal is tilted within the layer. Also, the second 1 /
The four-wave plate 309 has an optical axis in a direction substantially parallel to the optical axis of the first quarter-wave plate 308, and further has negative optical activity.

In the liquid crystal display device according to this embodiment, the liquid crystal layer 301 in the black display state is provided by the birefringence compensating plate 305.
And the second quarter-wave plate 309 for compensating for the birefringence of the first and second polarizing plates 30 during black display.
The difference from the liquid crystal display device according to the first embodiment is that the birefringence between 6 and 307 is set to 0 as a whole.

The liquid crystal display device according to this embodiment operates as follows.

Incident light that has passed through the first polarizing plate 306 is converted into linearly polarized light by the first polarizing plate 306.

The optical axis of the first quarter-wave plate 308 is tilted to the right 45 ° from the transmission axis of the polarizer when viewed from the incident direction. Also, the first quarter wave plate 308 is the second quarter wave plate 308.
Compensating with the wave plate 309, the first quarter wave plate 308
Is designed to cancel the birefringence of the.

In the white state, the negative birefringence compensating plate 305 using the discotic liquid crystal compensates the liquid crystal layer 301 having the bend orientation, so that the retardation becomes π. Therefore, the right-handed circularly polarized light incident on the birefringence compensator 30
The light is emitted as a left circularly polarized light from 5. In this case, the second 1 /
The four-wave plate 309 converts the left-hand circularly polarized light into linearly polarized light that is orthogonal to the incident linearly polarized light. That is, this is equivalent to the incident linearly polarized light being rotated by 90 °.

As described above, since the linearly polarized light emitted from the second quarter-wave plate 309 is parallel to the transmission axis of the second polarizing plate 307, the brightness becomes maximum.

In the black state, the negative birefringence compensating plate 305 using the discotic liquid crystal compensates the birefringence of the liquid crystal layer 301 having the bend orientation, and the retardation becomes zero. Therefore, the incident right circularly polarized light is emitted from the birefringence compensation plate 305 as the right circularly polarized light. Then, the second optical axis is arranged in parallel with the first quarter-wave plate 308.
Is converted into the same linearly polarized light as the incident linearly polarized light.

As a result, the outgoing linearly polarized light is blocked by the second polarizing plate 307 whose transmission axis is orthogonal to the transmission axis of the first polarizing plate 306.

As described above, normally white driving becomes possible. The transmittance in the white state and the black state is the liquid crystal layer 301.
It does not depend on the optical axis direction of and is always constant.

According to the liquid crystal display device of this embodiment,
As in the second embodiment, since the black state is compensated, an image with good visibility can be obtained regardless of the viewing angle of the liquid crystal display device, and a display device with a very wide viewing angle can be obtained.

Furthermore, reflecting the bend orientation,
Compared with other liquid crystal modes, a very fast response can be obtained.

(Fourth Embodiment) FIG. 4 is an exploded configuration diagram of a liquid crystal display device according to a fourth embodiment of the present invention.

The liquid crystal display device according to the present embodiment has a first substrate 402, a second substrate 403, and a first substrate 402.
The liquid crystal layer 401 sandwiched between the second substrate 403 and the second substrate 403 and having a bend orientation, the first quarter-wave plate 408 disposed outside the first substrate 402, and the first first wavelength plate 408. A first polarizing plate 406 arranged outside the quarter wave plate 408;
A biaxial birefringence compensating plate 405 arranged outside the second substrate 403, a second quarter-wave plate 409 arranged outside the biaxial birefringence compensating plate 405, and a second 1 And a second polarizing plate 407 arranged outside the quarter wavelength plate 409.

The biaxial birefringence compensation plate 405 is an optically positive birefringence compensation plate, and is the liquid crystal layer 4 in the black display state.
The birefringence of 01 is compensated.

The liquid crystal display device according to the present embodiment is different from the liquid crystal display device according to the first embodiment in that it has a biaxial birefringence compensating plate 405.

The liquid crystal display device according to this embodiment operates as follows.

Incident light that has passed through the first polarizing plate 406 is converted into linearly polarized light by the first polarizing plate 406. The optical axis of the first quarter-wave plate 408 is inclined 45 ° to the right from the transmission axis of the polarizer when viewed from the incident direction. Therefore, the incident light is converted from linearly polarized light to right circularly polarized light.

In the black state, the positive biaxial birefringence compensating plate 40 is used.
By 5, the birefringence of the liquid crystal layer 401 having the bend orientation is compensated, and the retardation becomes zero. Therefore,
The incident right circularly polarized light is a positive biaxial birefringence compensating plate 40.
The right circularly polarized light is emitted from 5 as it is. Then the first quarter
The second one in which the optical axis is arranged parallel to the optical axis of the wave plate 408.
The / 4 wavelength plate 409 converts the incident linearly polarized light into the same linearly polarized light.

The linearly polarized light thus emitted is blocked by the second polarizing plate 407 having a transmission axis orthogonal to the transmission axis of the first polarizing plate 406.

In the white state, the biaxial birefringence compensating plate 405 compensates the liquid crystal layer 401 having the bend alignment,
The retardation is π. Therefore, the incident right circularly polarized light is emitted from the positive biaxial birefringence compensating plate 405 as left circularly polarized light. In this case, the second quarter-wave plate 409 converts the left-hand circularly polarized light into linearly polarized light that is orthogonal to the incident linearly polarized light. That is, this is equivalent to the incident linearly polarized light being rotated by 90 °.

As a result, the linearly polarized light emitted from the second quarter-wave plate 409 is parallel to the transmission axis of the second polarizing plate 407, so that the brightness becomes maximum.

As described above, normally white driving becomes possible. The transmittance of the white state and the black state is the liquid crystal layer 401.
It does not depend on the optical axis direction of and is always constant.

In this embodiment, the liquid crystal layer 401 is regarded as one biaxial birefringent medium for compensation. On the high voltage side where most of the liquid crystal molecules rise vertically, it is difficult to compensate for with one positive biaxial birefringence compensating plate 405 to display black. In this case, therefore, normally black driving is performed.

As in the second embodiment, since the black state is compensated, an image with good visibility can be obtained regardless of the viewing angle of the liquid crystal display device, and a display device with a very wide viewing angle can be obtained. can get.

Further, reflecting that the liquid crystal of the liquid crystal layer 401 has the bend alignment, a very high speed response can be obtained as compared with other liquid crystal modes.

(Fifth Embodiment) FIGS. 5 and 6 show a fifth embodiment.
3 shows a liquid crystal display device according to the embodiment. FIG. 5 is a plan view showing one pixel of the liquid crystal display device according to the present embodiment,
FIG. 6 is a cross-sectional view of the liquid crystal display device according to this embodiment.

As shown in FIG. 5, in the active matrix type liquid crystal display device according to this embodiment, the scanning signal electrodes 508 and the video signals intersecting in a matrix are formed on the first substrate 606 (see FIG. 6). An electrode 510, a plurality of thin film transistors 511 formed corresponding to each intersection of the scanning signal electrode 508 and the video signal electrode 510, and a pixel formed in each region surrounded by the scanning signal electrode 508 and the video signal electrode 510. An electrode 504 is formed.

Further, as shown in FIG. 6, in the active matrix type liquid crystal display device according to the present embodiment,
The scanning signal electrode (gate electrode) 6 is formed on the first substrate 606.
08 and a first substrate 606 covering the scanning signal electrode 608.
The gate insulating film 609 formed on the gate insulating film 6
Video signal electrode 610 (source electrode) formed on 09
And the insulating film 6 that covers the drain electrode 612, the video signal electrode 610, the drain electrode 612, and the gate insulating film 609.
05 and the pixel electrode 604 formed on the insulating film 605.
And an alignment film 603 formed on the pixel electrode 604.

The pixel electrode 604 is connected to the drain electrode 6 through the contact hole 614 formed in the insulating film 605.
12 is connected.

Scan signal electrode (gate electrode) 608, video signal electrode 610 (source electrode) and drain electrode 612.
Form a thin film transistor 611.

Further, on the second substrate 601, a color filter 613, a light shielding film 615 formed on the same layer as the color filter 613, and a common electrode 602 formed on the color filter 613 and the light shielding film 615. And an alignment film 603 formed on the common electrode 602.

A liquid crystal layer 607 is sandwiched between the first substrate 606 and the second substrate 601.

In the liquid crystal display device according to this embodiment, the pixel electrode 604, the scanning signal electrode 608, the video signal electrode 610 and the thin film transistor 611 are separated by the insulating film 605.

Incidentally, in FIG. 5 and FIG.
The / 4 wavelength plate and the birefringence compensating plate are omitted.

In a normal transmissive liquid crystal display device, the scanning signal electrode 508, the video signal electrode 510, the thin film transistor 511, and the pixel electrode 504 are formed on the same layer. Therefore, the alignment of the liquid crystal molecules on the pixel electrode 504 is easily affected by the scanning signal electrode 508, the video signal electrode 510 and the thin film transistor 511, and the stability of the bend alignment may be a problem.

On the other hand, in the liquid crystal display device according to the present embodiment, the liquid crystal is switched by the active element using the thin film transistor 611, and further, the pixel electrode 604 and the scanning signal are provided on the first substrate 606. The electrode 608, the video signal electrode 610, and the thin film transistor 611 are separated by an insulating layer 605 to improve the stability of bend alignment, which is different from the first to fourth embodiments.

In this embodiment, the stability of bend alignment during driving, which is important in the OCB system, can be enhanced, and a display with a wide viewing angle and a high-speed response can be obtained.

This embodiment is based on the above-mentioned first to fourth embodiments.
It is possible to apply to any of the above embodiments.

In a space-division full-color liquid crystal display device, one pixel has a vertical-to-horizontal length ratio of approximately 3.
Although it has a long shape in the vertical direction of pair 1, considering the influence of the lateral electric field from the gate and the drain, if the alignment direction of the liquid crystal molecules at the interface is set parallel to the short side direction of the pixel, The stability of bend orientation is improved.

Although rubbing is a typical alignment method, it is not limited to rubbing. Photo-alignment techniques can also be used.

Further, in order to further improve the stability, an ultraviolet polymerizable monomer such as a liquid crystalline diacrylate monomer is added to the liquid crystal layer 607 and irradiated with ultraviolet rays in a bend-aligned state to be polymerized and stabilized. You can also plan.

(Sixth Embodiment) FIG. 7 shows a liquid crystal display device according to the sixth embodiment. FIG. 7 is a cross-sectional view of the liquid crystal display device according to this embodiment.

As shown in FIG. 7, in the liquid crystal display device according to the present embodiment, the scanning signal electrode (gate electrode) 708 and the scanning signal electrode 708 are covered on the first substrate 706. Gate insulating film 70 formed on 706
9, a video signal electrode 710 (source electrode) and a drain electrode 712 formed on the gate insulating film 709, an insulating film 705 covering the video signal electrode 710, the drain electrode 712, and the gate insulating film 709, and an insulating film 705. Above the color filter 713 formed on the scanning signal electrode 608, the insulating film 70 is formed in the same layer as the color filter 713.
5 and the color filter 71.
3 and the light shielding film 715, an overcoat film 716 formed on the insulating film 705, and an overcoat film 716.
A pixel electrode 704 formed above and an alignment film 703 formed on the pixel electrode 704 are formed.

The pixel electrode 404 is the overcoat film 71.
6 and the contact hole 71 formed in the insulating film 705
4 is connected to the drain electrode 712.

Scan signal electrode (gate electrode) 708, video signal electrode 710 (source electrode) and drain electrode 712.
Form a thin film transistor 711.

A common electrode 702 is formed on the second substrate 701, and an alignment film 703 formed on the common electrode 702.
And are formed.

A liquid crystal layer 707 is sandwiched between the first substrate 706 and the second substrate 701.

In this embodiment, the first substrate 706 is used.
The pixel electrode 704 is different from the fifth embodiment in that the scan signal electrode 708, the video signal electrode 710, and the thin film transistor 711 are separated by a color filter 713 to improve the stability of bend alignment.

In the fifth embodiment, the color filter 613 is formed on the side of the second substrate 601 having the common electrode 602, but in this embodiment, as shown in FIG. 7, the first substrate is It is provided on the 706 side. The scanning signal electrode 708, the video signal electrode 710, and the thin film transistor 711 are covered with an insulating layer 705, and the light shielding film 7 is formed thereon.
15 and the color filter 713 are formed. further,
The overcoat film 71 is covered with the overcoat film 71.
Pixel electrode 704 is formed on top of 6. Pixel electrode 704
Through the contact hole 714, the drain electrode 7
12 is connected.

In FIG. 7, the polarizing plate, the quarter-wave plate, and the birefringence compensating plate are omitted.

According to the liquid crystal display device of this embodiment,
The pixel electrode 704, the scanning signal electrode 708, the video signal electrode 710, and the thin film transistor 711 form an insulating film 705.
In addition to being separated through the color filter 713, high accuracy is not required for superimposing the first substrate 706 and the second substrate 701, which also has an advantage that a margin can be provided in a manufacturing process. .

According to the liquid crystal display device of this embodiment,
The stability of bend alignment during driving, which is important in the OCB method, is high, and a display with a wide viewing angle and high-speed response can be obtained.

This embodiment can be applied to any of the above-described first to fourth embodiments.

As in the case of the fifth embodiment, in a space-division full-color liquid crystal display device, one pixel has a shape in which the length-to-width ratio is approximately 3 to 1 and is long in the vertical direction. However, considering the influence of the lateral electric field from the gate and the drain, the stability of the bend alignment is improved by setting the alignment direction of the liquid crystal molecules at the interface parallel to the short side direction of the pixel.

Although rubbing is a typical alignment method, it is not limited to rubbing. A photo-alignment technique may be used.

Further, in order to further improve the stability, an ultraviolet polymerizable monomer such as a liquid crystalline diacrylate monomer is added to the liquid crystal layer 707 and irradiated with ultraviolet rays in a bend-aligned state to be polymerized and stabilized. You can also plan.

Hereinafter, examples will be given in which the above-described embodiment is further embodied.

Example 1 ITO is sputter-deposited on a glass substrate, and photolithography is used to perform IT.
The O electrodes were formed in a matrix. An alignment film was applied to the first and second substrates and baked at 200 ° C. for 1 hour to perform rubbing treatment. A sealant is applied around the first and second substrates so that the rubbing directions of the first and second substrates are parallel to each other and the electrodes are in a matrix form, that is, X.
The Y-shaped electrodes were alternately laminated so as to form a Y-shaped electrode, and the sealant was cured by heating.

A nematic liquid crystal having a dielectric anisotropy Δn of 0.13 was injected, and the injection hole was sealed with a photocurable resin. The polarizing plate and the quarter-wave plate were attached to the first and second substrates with the polarization axis of the polarizing plate and the optical axis of the quarter-wave plate tilted at 45 ° so that the circular polarization was reversed. .

A bias voltage was applied to the liquid crystal panel thus obtained, the orientation was changed from the splay orientation to the bend orientation, and the emitted light intensity was measured. As a result, the emitted light was irrespective of the transmission axis direction of the polarizing plate. It was confirmed that the maximum intensity was constant.

Further, reflecting the bend orientation,
It was confirmed that a display with excellent viewing angle characteristics was obtained as a whole, and in particular, the viewing angle characteristics of the polarizing plate in the transmission axis direction were excellent.

It was also confirmed that the response speed was as high as 7 ms even when the response speeds of ON and OFF were added.

(Example 2) A liquid crystal panel was assembled in the same manner as in Example 1.

A liquid crystal panel having two optically negative birefringence compensating plates using discotic liquid crystals so that the retardation of the liquid crystal layer is equal to that of the black display voltage of 5 V and its sign is opposite. After pasting before and after, the transmission axis of the polarizing plate and the optical axis of the 1/4 wavelength plate are arranged on the first and second substrates so that the polarizing plate and the 1/4 wavelength plate have opposite circular polarization. Was attached at an angle of 45 °.

A bias voltage was applied to the liquid crystal panel thus obtained, the alignment was transferred from the splay alignment to the bend alignment, and the viewing angle characteristics were measured. A wide and excellent viewing angle characteristic was obtained.

It was also confirmed that the transmission axis of the polarizing plate can be set in any direction. It was also confirmed that the response speed was fast.

(Example 3) A liquid crystal panel was assembled in the same manner as in Example 1.

One optically negative birefringence compensating plate using a discotic liquid crystal is used for the liquid crystal panel so that the retardation of the liquid crystal layer is equal to that of the black display voltage of 5 V and its sign is opposite. After being attached to the emission side, the transmission axis of the polarizing plate and the light of the 1/4 wavelength plate are arranged on the first and second substrates so that the polarizing plate and the 1/4 wavelength plate have opposite circular polarizations. The axis was tilted at 45 ° and attached. One quarter-wave plate was optically positive, and the other quarter-wave plate was optically negative. With this arrangement of the quarter-wave plate, the optical axes of the two quarter-wave plates are parallel to each other, and the birefringence of the two can be compensated for each other.

A bias voltage was applied to the liquid crystal panel thus obtained, the alignment was transferred from the splay alignment to the bend alignment, and the viewing angle characteristics were measured. A wide and excellent viewing angle characteristic was obtained.

It was also confirmed that the transmission axis of the polarizing plate can be set in any direction. It was also confirmed that the response speed was fast.

Example 4 A liquid crystal panel was assembled in the same manner as in Example 1.

The refractive index of one optically positive biaxial birefringence compensating plate is maximized so that the magnitude is equal to the retardation of the liquid crystal layer at the black display voltage of 2 V and the sign is opposite. After sticking to the exit side of the liquid crystal panel with the azimuth orthogonal to the rubbing direction, the polarizing plates and the quarter-wave plates on the first and second substrates are circularly polarized, which are opposite to each other.
The transmission axis of the polarizing plate and the optical axis of the 1/4 wavelength plate were attached at an angle of 45 °.

A bias voltage was applied to the liquid crystal panel thus obtained, the alignment was changed from the splay alignment to the bend alignment, and the viewing angle characteristics were measured. A wide and excellent viewing angle characteristic was obtained.

It was also confirmed that the transmission axis of the polarizing plate could be set in any direction. Also, the response speed is sub 10m
It was confirmed to be as fast as s.

Example 5 A scanning signal electrode was formed on the first substrate, and a gate insulating film was formed thereon. A video signal electrode intersecting the scanning signal electrode in a matrix and a plurality of thin film transistors were formed on the gate insulating film, corresponding to each intersection, and an insulating layer was formed thereon. A pixel electrode corresponding to each region surrounded by the scanning signal electrode and the video signal electrode was formed on the insulating layer, and connected to the drain electrode of the thin film transistor through a contact hole.

A liquid crystal panel was assembled as in Example 1 using the first substrate thus manufactured and the second substrate having the light shielding layer, the color filter and the common electrode. The rubbing direction was set parallel to the short side direction of each pixel.

In the same manner as in Example 3, the retardation and size of the liquid crystal layer at the time of black display voltage were equal, and
After attaching one optically negative birefringence compensating plate using discotic liquid crystal to the opposite side to the exit side of the liquid crystal panel, the polarizing plates and The polarization axis of the polarizing plate and the optical axis of the ¼ wavelength plate were attached at an angle of 45 ° so that the four wavelength plates had opposite circular polarization.

A bias voltage was applied to the liquid crystal panel thus obtained, and the alignment was changed from the splay alignment to the bend alignment. By counting the number of pixels transferred to the splay alignment, it was confirmed that the stability of the bend alignment was superior to the case where the pixel electrode was formed on the same layer as the scanning signal electrode, the video signal electrode and the thin film transistor.

It was also confirmed that the maximum intensity of the emitted light is constant regardless of the polarization axis direction of the polarizing plate.

A display with excellent viewing angle characteristics can be obtained as a whole,
In particular, it was confirmed that the viewing angle characteristics of the polarizing plate in the transmission axis direction were excellent.

Further, it was confirmed that the response speed was as high as 7 ms even when the response speeds of ON and OFF were added.

Example 6 A scanning signal electrode was formed on the first substrate, and a gate insulating film was formed thereon. On the gate insulating film, video signal electrodes intersecting the scanning signal electrodes in a matrix and a plurality of thin film transistors were formed corresponding to the respective intersections, and an insulating layer was covered thereover. A color filter and a light shielding film were formed on the insulating layer and further covered with an overcoat film. A pixel electrode corresponding to each region surrounded by the scanning signal electrode and the video signal electrode was formed on the overcoat film, and connected to the drain electrode of the thin film transistor through a contact hole.

A liquid crystal panel was assembled as in Example 1 using the first substrate thus prepared and the second substrate having a common electrode. The rubbing direction was set parallel to the short side direction of each pixel.

As in Example 5, the optically negative birefringence compensating plate 1 using discotic liquid crystal so that the retardation of the liquid crystal layer is equal to that of the liquid crystal layer at the time of black display voltage and the sign is opposite. After attaching the sheet to the exit side of the liquid crystal panel, the polarizing plate and the quarter wave plate are arranged on the first and second substrates so that the polarization axes of the polarizing plate and the quarter wavelength plate are 1/4 and 1/4, respectively. The wave plate was attached with the optical axis inclined at 45 °.

A bias voltage was applied to the liquid crystal panel thus obtained, and the alignment was changed from the splay alignment to the bend alignment. Compared to the case where the pixel electrode is formed on the same layer as the scanning signal electrode, the video signal electrode and the thin film transistor,
It was confirmed that the bend orientation was excellent in stability.

It was also confirmed that the maximum intensity of the emitted light is constant regardless of the polarization axis direction of the polarizing plate.

A display having excellent viewing angle characteristics can be obtained as a whole,
In particular, it was confirmed that the polarizing plate had excellent viewing angle characteristics in the transmission axis direction. It was also confirmed that the response speed was extremely fast.

[0168]

As described above, according to the liquid crystal display device of the present invention, as long as the angle between the transmission axis of the polarizing plate and the optical axis of the quarter wavelength plate is kept at 45 °, the bend alignment is achieved. The transmission axis of the polarizing plate can be arranged without being controlled by the direction of the optical axis of the liquid crystal layer. Therefore, more desirable viewing angle characteristics can be obtained according to the user's wish without impairing the optical symmetry and the stability of the bend alignment.

For example, the viewing angle in the horizontal and vertical directions can be widened so that the display becomes more natural.

Furthermore, since circularly polarized light is used,
Even if the rubbing angle is slightly deviated, the optical characteristics are not significantly deteriorated, and there is an advantage that a margin can be created in the manufacturing process.

[Brief description of drawings]

FIG. 1 is an exploded configuration diagram of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is an exploded configuration diagram of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 3 is an exploded configuration diagram of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 4 is an exploded configuration diagram of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 5 is a plan view of one pixel of a liquid crystal display device according to a fifth embodiment of the present invention.

FIG. 6 is a sectional view of a liquid crystal display device according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a liquid crystal display device according to a sixth embodiment of the present invention.

FIG. 8 is an exploded configuration diagram of a conventional liquid crystal display device.

[Explanation of symbols]

101, 201, 301, 401 Liquid crystal layers 102, 202, 302, 402 having bend orientation First substrate 103, 203, 303, 403 Second substrate 106, 206, 306, 406 First polarizing plate 107 , 207, 307, 407 Second polarizing plate 108, 208, 308, 408 First quarter wave plate 109, 209, 309, 409 Second quarter wave plate 204 First birefringence compensation plate 305 Birefringence compensation plate 504 Pixel electrode 508 Scan signal electrode 510 Video signal electrode 511 Thin film transistor 601, 701 First substrate 602, 702 Common electrode 603, 703 Alignment film 604, 704 Pixel electrode 605, 705 Insulating layer 606, 706 Second Substrate 607, 707 Liquid crystal molecule 608, 708 Scan signal electrode (gate electrode) 609, 709 Gate insulation 610 and 710 video signal electrode (source electrode) 611 and 711 TFT 612,712 drain electrodes 613,713 color filters 614,714 contact holes 615,715 shielding film 716 overcoat film

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshiya Ishii             5-7 Shiba 5-1, Minato-ku, Tokyo NEC Corporation             Inside the company (72) Inventor Kiyomi Hayakawa             5-7 Shiba 5-1, Minato-ku, Tokyo NEC Corporation             Inside the company (72) Inventor Hiroaki Matsuyama             5-7 Shiba 5-1, Minato-ku, Tokyo NEC Corporation             Inside the company (72) Inventor Yoshihiko Hirai             5-7 Shiba 5-1, Minato-ku, Tokyo NEC Corporation             Inside the company F-term (reference) 2H049 BA02 BA05 BA07 BA42 BA43                       BB03 BB42 BC14 BC22                 2H088 HA16 HA17 JA09 KA06 KA07                       KA26 KA27                 2H090 HB16Y HB17Y HD14 LA08                       LA09 MA01 MA07 MA11 MB12                 2H091 FA08X FA08Z FA11X FA11Z                       FD06 FD10 GA11

Claims (13)

[Claims] 1. A first substrate, a second substrate, a liquid crystal layer sandwiched between the first substrate and the second substrate and having a bend orientation, and the first substrate. A first quarter-wave plate disposed outside the first substrate, a second quarter-wave plate disposed outside the second substrate, and a first quarter-wave plate disposed outside the first quarter-wave plate. At least one first polarizing plate, and at least one second polarizing plate disposed outside the second quarter-wave plate. 2. The first quarter-wave plate is optically positive and the second quarter-wave plate is optically negative, and are arranged to compensate for birefringence with respect to each other. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is provided. 3. The first quarter-wave plate and the first polarizing plate are set so as to have opposite circular polarizations, respectively, and the second quarter-wave plate and the second polarization plate are set. The plates are set so as to have circular polarizations opposite to each other, and the optical axis of the first quarter-wave plate and the transmission axis of the first polarizing plate are inclined by 45 degrees with respect to each other, and The liquid crystal display device according to claim 1, wherein the optical axis of the quarter-wave plate and the transmission axis of the second polarizing plate are inclined by 45 degrees with respect to each other. 4. A first birefringence compensating plate arranged between the first substrate and the first quarter-wave plate, the second substrate and the second quarter-wave plate. A second birefringence compensating plate disposed between the plate and the second birefringence compensating plate, wherein both of the first and second birefringence compensating plates have constituents that are optically negative, and 2. The structure has a structure in which the inclination of the principal axis of the liquid crystal layer changes, and the birefringence of the liquid crystal layer is compensated by the first and second birefringence compensating plates.
4. The liquid crystal display device according to any one of items 1 to 3. 5. A birefringence compensating plate disposed between the second substrate and the second quarter-wave plate is further provided, wherein the birefringence compensating plate has optical components as optical components. The structure is negative and has a structure in which the inclination of the principal axis in the layer changes, and the birefringence compensating plate compensates the birefringence of the liquid crystal layer and the birefringence of the first quarter-wave plate. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a liquid crystal display device. 6. An optically positive uniaxial birefringence compensation plate or biaxial birefringence compensation plate disposed between the second substrate and the second quarter-wave plate. It is provided, Comprising: Compensating the birefringence of the said liquid crystal layer by the said uniaxial birefringence compensating plate or a biaxial birefringence compensating plate, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. Liquid crystal display device. 7. A plurality of scanning signal electrodes, a plurality of video signal electrodes intersecting the scanning signal electrodes in a matrix, and intersections of the scanning signal electrodes and the video signal electrodes on the first substrate. A plurality of thin film transistors formed corresponding to, a pixel is formed in each region surrounded by the scanning signal electrode and the video signal electrode, and each pixel is further formed on the first substrate. A pixel electrode connected to a thin film transistor corresponding to a pixel is formed, and a common electrode for applying a reference potential across a plurality of pixels is formed on the second substrate. Item 7. The liquid crystal display device according to any one of items 1 to 6. 8. The interlayer insulating film for separating the pixel electrode from the scanning signal electrode, the video signal electrode and the thin film transistor is formed on the first substrate. 7. The liquid crystal display device according to item 7. 9. The scan electrode on the first substrate,
A color filter layer is formed on the video signal electrode and the thin film transistor, and the pixel electrode, the scanning signal electrode, the video signal electrode, and the thin film transistor are separated via the color filter layer. The liquid crystal display device according to claim 7, wherein the liquid crystal display device is a liquid crystal display device. 10. The liquid crystal display device according to claim 7, wherein the liquid crystal layer contains an ultraviolet polymerizable monomer for stabilizing bend alignment. 11. The ultraviolet polymerizable monomer is a liquid crystalline diacrylate monomer.
The liquid crystal display device according to item 0. 12. The liquid crystal alignment in the vicinity of the interface between the first substrate and the second substrate and the liquid crystal layer is substantially parallel to the short side direction of the pixel. The liquid crystal display device according to any one of claims. 13. A method of manufacturing a liquid crystal display device according to claim 1, comprising a step of controlling alignment of liquid crystal molecules of the liquid crystal layer by a photo-alignment technique. A method for manufacturing a liquid crystal display device.