JPH09146086A - Liquid crystal display device - Google Patents

Abstract

(57) An object of the present invention is to provide a liquid crystal display device having a high contrast ratio and realizing a display having no viewing angle dependence and which can be put to practical use and has a high-speed response. A liquid crystal display element performing a display operation within an applied voltage range in which liquid crystal molecules 17c included in a central region of a liquid crystal layer 17 almost rises, and a liquid crystal having a predetermined arrangement under any voltage applied state. At least one of the polarizing plate and the liquid crystal cell is provided between the liquid crystal cell and at least one of the polarizing plates so that the molecules 17a-17e provide the transmitted light with a second retardation for canceling and compensating the first retardation given to the transmitted light passing through the liquid crystal cell. And at least one optical anisotropic element 18, 19 having a negative optical anisotropy according to a predetermined arrangement of liquid crystal molecules.

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, and more particularly, to a liquid crystal display device having an OCB mode or a display mode similar to OCB mode in which the viewing angle dependence of contrast ratio and display color is improved. is there.

[0002]

2. Description of the Related Art In recent years, liquid crystal display elements, which have the great advantages of thinness, light weight, and low power consumption, have been actively used as display devices for personal OA equipment such as Japanese word processors and desktop personal computers. Most of liquid crystal display elements (hereinafter abbreviated as “LCD”) use twisted nematic liquid crystal, and the display method thereof can be roughly classified into two methods of an optical rotation mode and a birefringence mode.

LCDs of optical rotation mode include, for example, a twisted nematic (T
N) type liquid crystal (TN-LCD), which in principle exhibits a high contrast ratio and a good gradation display property in black and white display, and includes a simple matrix drive liquid crystal display element and a switching element used for a clock, a calculator and the like. An active matrix drive liquid crystal display element provided for each pixel, a combination of this active matrix drive liquid crystal display element and a color filter,
Color type active matrix drive liquid crystal display device (TFT-LCD) applied to full color display liquid crystal television
And MIM-LCD).

On the other hand, as a typical example of a birefringence mode display type LCD, a super twist nematic (STN: Sup) having a liquid crystal molecule arrangement twisted by 90 ° or more is usually used.
erTwisted Nematic) type liquid crystal (STN
There is one LCD). Since this STN-LCD has steep electro-optical characteristics, even if a switching element such as a thin film transistor or a diode is not provided for each pixel,
By adopting a simple matrix type electrode structure having a simple structure and low manufacturing cost, a large capacity (large screen) display can be easily realized by time division driving.

Performances required for future liquid crystal display devices include high-speed response and wide viewing angle. The optical response speed (expressed by the time from the change of the applied voltage to the change of the display state) of the liquid crystal display element described above is usually a simple matrix drive TN-LCD or STN-LCD.
Then, it is several tens ms to several hundred ms. On the other hand, TN-L
When the CD is statically driven, or when the TFT is driven by a T drive that can pseudo-statically drive the liquid crystal.
In the case of N-LCD, the response speed is considerably improved and white /
When black switching is performed, a response speed of about 30 ms can be obtained. Therefore, for example, when an LCD is used as a display of a personal computer, the STN-LCD, which is a simple matrix drive LCD, has an insufficient optical response speed of the LCD when the cursor is moved quickly, so that the cursor display becomes thin and difficult to see. On the other hand, when a TN mode TFT-LCD is used, L
Since the response speed of the CD is fast, a clear display can be obtained even when the cursor is moved quickly.
Even in the T-LCD, the response speed may be insufficient. As mentioned above, the response speed of the TFT-LCD is 3
About 0 ms can be obtained, which is the case of binary display. Examining the response speed between gray scales during gray scale display shows that in a normally white mode TN-LCD that produces white when no voltage is applied, it is particularly close to white and between white and white. It was found that the switching between the gradations close to is significantly slower than that in the case of binary display and is 100 ms or more.

Therefore, when a moving halftone display image such as a TV image is displayed, the TFT-LC is displayed.
Even with D, the response speed may be insufficient, and phenomena such as blurred outlines are observed, which is a problem.

According to experiments conducted by the inventors, a good T
In order to obtain the V moving image display, the response speed of the LCD is the frame period of the TV (1 / 30s) even in the gradation display.
It is desirable that the following response speed be achieved.

Further, it is desirable that display defects such as inversion, black crushing, and white spots do not appear even when the display section is obliquely observed during gradation display.

As described above, TN-LCD, STN-L
Neither the CD nor the TN mode TFT-LCD has come to satisfy these performances.

As a means for solving such a problem, Uchida et al. Apply a voltage to a nematic liquid crystal layer having a non-twisted splay alignment to form a bend alignment, and tilt the liquid crystal molecules within a range of applied voltage for maintaining this bend alignment. The OCB mode (Optically Complement) is a birefringence effect type liquid crystal display mode in which the state is controlled by an applied voltage value and the phase difference of transmitted light in a liquid crystal layer is controlled by a voltage.
Nested Birefringence mod
e) was proposed (Y. Yamaguchi, eta
l. , SID'93 Digest, pp277-28
0 (1993), or T.I. Miyashita, e
t al. , Eurodisplay Digest,
pp277-280 (1993), or C-L. K
uo, et al. , SID'94 Digest, pp
927-930 (1994), or T.I. Miyas
hita, et al. , SID'95 Diges
t, pp 797-800 (1995), etc.). This O
LCD adopting CB mode has wide viewing angle and fast response.
It is attracting attention as a CD.

A liquid crystal cell in which liquid crystal molecules are bend-aligned has a π
It is known as a cell (pi cell) and has been known to have a faster response than before (for example, Saito et al .: Proceedings of the 5th Liquid Crystal Conference, pp. 166, 169, 1979).
Alternatively, Japanese Patent Laid-Open Publication No. 55-142316. Alternatively, P. Boss, et al. SID '
83 Digest, pp30-31, 1983. Alternatively, patent publication: Japanese Patent Publication No. 6-56464. ).

In this pi cell, the OCB mode LCD has a liquid crystal molecule alignment in which the liquid crystal molecules in the vicinity of the upper and lower substrates are the same and there is no twist, and the optically anisotropic element is used as an observation side substrate and an observation side polarizing plate. LCD inserted between
It is.

FIG. 6 is a schematic configuration diagram of an OCB mode LCD. Electrodes (not shown) are respectively formed on one main surface, and the main surfaces are arranged so as to face each other to form a liquid crystal cell 60. The first substrate 61 and the second substrate 62 are two substrates.
A first polarizing plate 63 and a second polarizing plate 64 are arranged on the respective outer sides so that their polarization directions are orthogonal to each other, and between the first substrate 61 and the first polarizing plate 63. Is a biaxial retardation plate (optical anisotropic element) 65, and a biaxial retardation plate (optical anisotropic element) 66 is inserted between the second substrate 62 and the second polarizing plate 64. There is. The rubbing directions 61R and 62R of the first and second substrates 61 and 62 are parallel to each other. Therefore, the liquid crystal molecules contained in the liquid crystal layer 67 sandwiched between the first substrate 61 and the second substrate 62 have one plane of one plane when a predetermined voltage is applied.
A bend sequence is formed within 0P.

FIG. 7 is an explanatory view schematically showing the alignment of liquid crystal molecules in the liquid crystal layer in each voltage application state of the OCB mode LCD. For simplification of the drawing, only a sufficient number of liquid crystal molecules are shown for explanation. First substrate 71 and second
The liquid crystal layer 73 is sandwiched between the first substrate 71 and the liquid crystal molecules 73a which are in contact with the first substrate 71 in the first substrate vicinity region 73A, and the second substrate vicinity region. Liquid crystal molecules 73e in contact with the second substrate 72 in 73C,
Liquid crystal molecules 73b, 73c, 73d in a central region 73B between the first and second substrate neighboring regions 73A and 73C are included. For the first and second substrates, the first substrate 7
The alignment direction of the liquid crystal molecules 73a in contact with the first substrate 72 and the second substrate 72
The alignment process is performed so that the alignment direction of the liquid crystal molecules 73e in contact with is the same. The liquid crystal molecule alignment changes as shown in FIGS. 7A, 7B, and 7C according to the change in the value of the voltage applied to the liquid crystal layer 73.

FIG. 7A shows the alignment of liquid crystal molecules when no voltage is applied. Liquid crystal molecules 73a in contact with the first substrate 71 and liquid crystal molecules 73e in contact with the second substrate 72
And liquid crystal molecules 73b, 73c, 73 in the central region 73B.
d means that a splay array is formed substantially parallel to the first and second substrates 71 and 72.

FIG. 7B shows the alignment of the liquid crystal molecules in the state where the first predetermined voltage is applied to the liquid crystal layer 73.
Only the liquid crystal molecules 73c in the central portion of the central region 73B have the first
And the second substrates 71 and 72 are aligned substantially parallel to the normal direction, the liquid crystal molecules 73b are aligned so as to gradually change from the alignment direction of the liquid crystal molecules 73a to the alignment direction of the liquid crystal molecules 73c, and the liquid crystal molecules 73d are aligned. The orientation is such that the orientation of the liquid crystal molecules 73d gradually changes to the orientation of the liquid crystal molecules 73c.

FIG. 7C shows the alignment of liquid crystal molecules in a state in which a larger second predetermined voltage is applied to the liquid crystal layer 73. Liquid crystal molecules 73a in contact with the first substrate 71,
The liquid crystal molecules 73e in contact with the second substrate 72 are arranged substantially parallel to the first and second substrates 71 and 72,
Liquid crystal molecules 73b, 73c, 73d in the central region 73B
All form a bend array oriented substantially parallel to the normal direction of the first and second substrates 71 and 72.

In the OCB mode, the applied voltage is controlled and changed between the first predetermined voltage application state of FIG. 7B and the second predetermined voltage application state of FIG. 7C to change the liquid crystal. It is a birefringence effect type liquid crystal display mode in which a display operation is performed based on the phase change in the layer 73, and the value of the response speed thereof is a necessary and sufficient value of several ms according to the literature relating to the OCB mode described above. It has been reported.

In the OCB mode display, the alignment of the liquid crystal molecules is such that the alignment direction of the liquid crystal molecules 73a in contact with the first substrate 71 and the alignment direction of the liquid crystal molecules 73e in contact with the second substrate 72 are the same. The feature is that the half and the bottom half are always almost symmetrical. Furthermore, FIG.
As shown in FIG. 2, biaxial retardation plates 65 and 66 are provided on both sides of the liquid crystal cell 60. Therefore, in the range of the viewing angle (observation viewing angle) that is substantially parallel to the plane 60P in FIG. 6, the upper half and the lower half of the liquid crystal are observed to have a substantially symmetrical shape, and in this case, the liquid crystal layer 73.
Since the refractive index ellipsoid of is a sphere, there is almost no viewing angle dependency in this range, and a wide viewing angle can be obtained. Also, the first
Alternatively, since the biaxial retardation plates 65 and 66 are designed to compensate the retardation in the normal direction of the substrate surface for the liquid crystal molecule array in the second predetermined voltage application state, at least the substrate surface A good display can be obtained in the line direction.

FIG. 8 is an application example of an OCB mode LCD, and is an explanatory view schematically showing the liquid crystal molecule arrangement in the liquid crystal layer in each voltage application state of a π twist cell (pi twist cell) as a liquid crystal cell. . π twist cell OCB
The whole configuration of the mode LCD is also a normal OCB mode LCD
Similarly to the above, the configuration is shown in FIG. Similar to FIG. 7, in FIG. 8, only a sufficient number of liquid crystal molecules are shown for the sake of simplification of the drawing. The liquid crystal layer 83 is sandwiched between the first substrate 81 and the second substrate 82,
In the liquid crystal layer 83, the first substrate in the first substrate vicinity region 83A is formed.
Liquid crystal molecules 83a in contact with the substrate 81 and liquid crystal molecules 83e in contact with the second substrate 82 in the second substrate vicinity region 83C.
And liquid crystal molecules 83b, 83c, 83d in the central region 83B between the first and second substrate neighboring regions 83A and 83C.
And are included. An alignment treatment is performed on the first and second substrates so that the alignment direction of the liquid crystal molecules 83a in contact with the first substrate 81 and the alignment direction of the liquid crystal molecules 83e in contact with the second substrate 82 form an angle of 180 °. Has been applied. That is, the liquid crystal molecule array of the π twist cell has a twist of 180 °. Then, according to the change in the value of the voltage applied to the liquid crystal layer 83, the liquid crystal molecule alignment changes as shown in FIGS.

FIG. 8 (a) shows the alignment of liquid crystal molecules when no voltage is applied. Liquid crystal molecules 83a in contact with the first substrate 81 and liquid crystal molecules 83e in contact with the second substrate 82
And liquid crystal molecules 83b, 83c, 83 in the central region 83B.
d is a TN mode liquid crystal molecule array which is substantially parallel to the first and second substrates 81 and 82 and has a twist angle of 180 °.

FIG. 8B shows the alignment of the liquid crystal molecules in the state where the first predetermined voltage is applied to the liquid crystal layer 83.
Only the liquid crystal molecules 83c in the central portion of the central region 83B are
And the second substrates 81 and 82 are aligned substantially parallel to the normal direction, the liquid crystal molecules 83b are aligned so as to gradually change from the alignment direction of the liquid crystal molecules 83a to the alignment direction of the liquid crystal molecules 83c, and the liquid crystal molecules 83d are aligned. The liquid crystal molecules are aligned so as to gradually change from the alignment direction of the liquid crystal molecules 83d to the alignment direction of the liquid crystal molecules 83c.

FIG. 8 (c) shows the alignment of the liquid crystal molecules in the state in which a larger second predetermined voltage is applied to the liquid crystal layer 83. The alignment direction of the liquid crystal molecules 83a in contact with the first substrate 81 and the alignment direction of the liquid crystal molecules 83e in contact with the second substrate 82 form an angle of 180 ° with each other, and the first and second substrates 81 and 82 are formed. Liquid crystal molecules 83b, 83c, and 83d in the central region 83B are arranged in parallel with each other.
All of them form a bend array oriented substantially parallel to the normal direction of the first and second substrates 81 and 82.

The display mode of the π-twist cell OCB mode LCD is the same as the first predetermined voltage application state of FIG.
In the birefringence effect type liquid crystal display mode, the display operation is performed based on the phase change in the liquid crystal layer 83 by controlling and changing the applied voltage between the second predetermined voltage application state of (c) and Is known to have a fast response.

When the π twist cell OCB mode LCD is displayed, the alignment of liquid crystal molecules 83a in contact with the first substrate 81 and the alignment direction of liquid crystal molecules 83e in contact with the second substrate 82 are 180 degrees relative to each other. The liquid crystal layer 83 has an upper half and a lower half, which are always substantially symmetrical in shape, and are arranged on both sides of the liquid crystal cell 60 as shown in FIG. Is a biaxial retardation plate 65
And 66 are provided.

Therefore, the biaxial retardation plates 65 and 66 are designed to compensate for retardation in the normal direction of the substrate surface with respect to the liquid crystal molecule alignment in the first or second predetermined voltage application state. , The refractive index ellipsoid of the liquid crystal cell 60 is a sphere in the range of the viewing angle (observation viewing angle) that is substantially parallel to the plane 60P in FIG.
In this range, there is almost no viewing angle dependency, a wide viewing angle can be obtained, and good display can be obtained at least in the normal direction of the substrate surface.

The above OCB mode and π twist cell OC
In addition to the B-mode display mode, there are several types of high-speed display modes using the birefringence effect. For example, by changing the alignment treatment method between one substrate and the other substrate, one substrate is subjected to vertical alignment treatment, and the other substrate is subjected to normal tilt alignment treatment to form a hybrid alignment (HybridAl).
Ignition Nematic (HAN) mode has been proposed.

FIG. 9 is a schematic configuration diagram of a HAN mode cell. FIG. 9A shows the liquid crystal molecule alignment in the first predetermined voltage applied state (including no voltage applied state). The liquid crystal layer 93 includes a first substrate 91 and a second substrate 92.
Among the liquid crystal molecules contained in the liquid crystal layer 93, which are sandwiched between the liquid crystal molecules 93 a and the liquid crystal molecules 93 a on the surface of the first substrate 91.
Are aligned substantially perpendicular to the substrate surface, the liquid crystal molecules 93c on the second substrate 92 surface are aligned substantially parallel to the substrate surface, and the liquid crystal molecules 93b in the central region of the liquid crystal layer 93 are separated from the first substrate 91. Toward the second substrate 92, liquid crystal molecules 93a
The liquid crystal molecules 93c are aligned so as to gradually change from the liquid crystal molecules 93c. That is, the liquid crystal molecule alignment in the liquid crystal layer 93 continuously changes from the vertical alignment to the tilt alignment.

FIG. 9B shows the alignment of the liquid crystal molecules when the second predetermined voltage is applied to the liquid crystal layer 93.
The liquid crystal molecules 93a and 93b except the liquid crystal molecule 93c on the surface of the second substrate 92 which is oriented substantially parallel to the surface of the substrate are oriented substantially perpendicular to the surface of the substrate. As described above, the HAN mode array form has a structure in which only the upper half or the lower half of the OCB mode array form is formed.

In the HAN mode, the applied voltage is controlled and changed between the first predetermined voltage application state of FIG. 9A and the second predetermined voltage application state of FIG. 9B to change the liquid crystal. This is a birefringence effect type liquid crystal display mode in which a display operation is performed by utilizing the birefringence effect based on the phase change in the state where the arrangement is continuously changed in the layer 93, and a high-speed response equivalent to that of the OCB mode is obtained. To be

Similarly, as an example in which a high-speed response is obtained, on the contrary, an HSN mode cell in which an n-type nematic liquid crystal is homeotropically aligned is an ECB (Electrical) cell.
lyControlled Birefringenc
e) The case where it drives is mentioned.

FIG. 10 is a schematic configuration diagram of the HSN mode cell. FIG. 10A shows the liquid crystal molecule alignment in the first predetermined voltage application state (including the voltage non-application state). The liquid crystal layer 103 is sandwiched between the first substrate 101 and the second substrate 102, and the liquid crystal molecules 103a, 103b, and 103c included in the liquid crystal layer 103 are all aligned substantially perpendicular to the substrate surface. doing.

FIG. 10B shows the alignment of the liquid crystal molecules in the state where the second predetermined voltage is applied to the liquid crystal layer 103. Liquid crystal molecules 103a contained in the liquid crystal layer 103,
Since 103b and 103c are n-type, they are gradually tilted by applying a voltage, and in the state where the second predetermined voltage is applied, they are all oriented substantially parallel to the substrate surface. In the HSN mode, in order to specify the tilting direction of the liquid crystal molecules, it is desirable that the liquid crystal molecules are initially tilted slightly from the normal line direction of the substrate surface.

In the HSN mode, the applied voltage is controlled and changed between the first predetermined voltage application state of FIG. 10A and the second predetermined voltage application state of FIG. 10B to change the liquid crystal. A display operation is performed by utilizing a birefringence effect generated by tilting liquid crystal molecules that are aligned substantially vertically in the layer 103. When the HSN mode is driven by ECB, the arrangement form of the liquid crystal molecules is substantially symmetrical to the OCB mode,
A wide viewing angle can be realized.

As described above, the OCB mode or OC
In the display mode similar to the B mode, the display operation is performed in a state where the liquid crystal molecules in the central region of the liquid crystal layer are almost raised, that is, the alignment direction of the liquid crystal molecules is substantially parallel to the normal direction of the substrate surface. Further, in the display mode, one of the axes of the rising direction of the liquid crystal molecules on the surface of the substrate and the one on the surface of the other substrate are substantially symmetrical with respect to the liquid crystal layer. The liquid crystal molecule arrangement is characterized in that the upper half and the lower half of the liquid crystal layer are always almost symmetrical, so that the refractive index is compensated inside the liquid crystal layer and parallel to the plane containing the liquid crystal molecule arrangement. It is possible to obtain a wide field of view that is symmetric with respect to different directions.

Further, in order to obtain a wide viewing angle in other display modes similar to the OCB mode, in the HAN mode, the arrangement form of the liquid crystal molecules seems to be constituted by only the upper half or the lower half of the OCB mode. Take structure,
Display operation is performed by combining with a retardation plate (optical anisotropic element). In HSN mode, in the case of ECB driving,
The display operation is performed with a configuration in which the alignment form of the liquid crystal molecules is almost symmetrical to the OCB mode.

[0037]

[Problems to be Solved by the Invention] However, OCB
Each of the display modes similar to the mode or OCB mode (hereinafter, appropriately referred to as “OCB mode and the like”) has a configuration for obtaining the above-mentioned wide viewing angle and high-speed response, mainly due to the form of the liquid crystal molecule alignment The following problems occur.

That is, as the display system of the OCB mode and the like, there are two types of systems of normally white mode and normally black mode. In the normally white mode, a bright state display (white display) is performed in the first predetermined voltage application state, and a dark state display (black display) is performed in the second predetermined voltage application state. However, in order to obtain a sufficient dark state display only by the combination of the liquid crystal cell and the polarizing plate in the second predetermined voltage applied state, the second predetermined voltage needs to be 10V or higher. This is an essential problem in the OCB mode and the like due to the configuration, and therefore it is difficult to put the configuration for obtaining the dark state display only by combining the liquid crystal cell and the polarizing plate into practical use.

Therefore, OC in normally white mode
In order to put a B-mode liquid crystal display device into practical use, it is necessary to obtain a dark state display in combination with an optical anisotropic element.

Further, in order to obtain the dark state display in the normally black mode, the composite refractive index with the refractive index ellipsoid in the first predetermined voltage applied state (including no voltage applied state) of the liquid crystal cell. An optical anisotropic element having an index ellipsoid such that the ellipsoid becomes a sphere is required.

However, in both the normally white mode and the normally black mode, when a dark state display is obtained in combination with a normal uniaxial or biaxial optical anisotropic element, the substrate surface method is used. It is easy to obtain a good dark state display in the line direction, that is, in front of the display unit, but when the display unit is viewed obliquely due to the form of the liquid crystal molecule alignment such as the OCB mode described above, that is, When viewed from a direction that makes a certain angle with respect to the normal direction of the substrate surface, there is a problem that light leakage always occurs in any direction, and as a result, display reversal occurs, This problem is caused by OCB mode, π twist cell O
It is common to all of the CB mode, the HAN mode, and the HSN mode.

The present invention has been made in view of the above problems, and an object thereof is to provide a liquid crystal display device of an OCB mode or a display mode similar to the OCB mode in which the viewing angle dependence of the contrast ratio and the display color is improved. Is to provide.

[0043]

According to the liquid crystal display element of the present invention, electrodes are formed on one main surface, and two substrates constituting a liquid crystal cell and each main electrode having the electrodes are formed. A liquid crystal layer made of a liquid crystal material containing a nematic liquid crystal composition as a liquid crystal molecule, and a liquid crystal layer sandwiched between two substrates arranged so as to face each other, and electrodes for the two substrates. Two polarizing plates respectively arranged on the main surface side other than the main surface, and a first retardation that liquid crystal molecules in a predetermined array under any voltage applied state give to transmitted light passing through the liquid crystal cell. It is inserted and disposed between at least one of the polarizing plates and the liquid crystal cell so as to give a second retardation for offsetting and compensating to the transmitted light, and a negative optical anisotropy corresponding to a predetermined arrangement of liquid crystal molecules is provided. Having at least one optic The liquid crystal molecules included in the central region of the liquid crystal layer are characterized by performing a display operation within an applied voltage range in which the liquid crystal molecules contained in the central region of the liquid crystal layer are almost up. A liquid crystal display element that performs a display operation within a range of an applied voltage that is in a rising state has a first retardation that liquid crystal molecules in a predetermined array under any voltage application state give to transmitted light passing through a liquid crystal cell. It is inserted and disposed between at least one of the polarizing plates and the liquid crystal cell so as to give a second retardation for offsetting and compensating to the transmitted light, and a negative optical anisotropy corresponding to a predetermined arrangement of liquid crystal molecules is provided. Since at least one optically anisotropic element is provided, a liquid crystal display element having a high contrast ratio and realizing a display having no viewing angle dependence and capable of being put to practical use and having a high-speed response For example, OCB mode LCD, [pi twist cell OCB mode LCD, HA
An N mode LCD and an HSN mode LCD can be provided.

Between two substrates, each of which has an electrode formed on one main surface and which constitutes a liquid crystal cell, and two substrates which are arranged so as to oppose each other so that the respective one main surfaces on which the electrodes are formed face each other. A liquid crystal layer made of a liquid crystal material containing a nematic liquid crystal composition as liquid crystal molecules, and two polarization plates disposed on each main surface side other than one main surface on which electrodes of the two substrates are formed. A plate and liquid crystal molecules of a predetermined array under any voltage applied state give a second retardation to the transmitted light which cancels and compensates a first retardation given to the transmitted light passing through the liquid crystal cell. And at least one optically anisotropic element having a negative optical anisotropy according to a predetermined arrangement of liquid crystal molecules, the liquid crystal cell being provided with at least one polarizing plate and the liquid crystal cell. One of the substrates The alignment treatment on one main surface of the substrate is a tilt alignment treatment, and the alignment treatment on the other main surface of the substrate is a liquid crystal cell subjected to a hybrid alignment treatment which is a vertical alignment treatment, In the liquid crystal cell, a hybrid alignment process in which the alignment treatment on one main surface of one of the two substrates is a tilt alignment treatment and the alignment treatment on the other main surface of the one substrate is a vertical alignment treatment is performed. Provided is a liquid crystal display element having a high contrast ratio and realizing a display having no viewing angle dependence, which is a liquid crystal cell subjected to a practicable application, and a practically applicable high-speed response liquid crystal display element such as a HAN mode LCD. be able to.

Between two substrates, each of which has an electrode formed on one principal surface and which constitutes a liquid crystal cell, and two substrates which are arranged so as to oppose each other so that the respective principal surfaces having electrodes are opposed to each other. A liquid crystal layer made of a liquid crystal material containing a nematic liquid crystal composition as liquid crystal molecules, and two polarization plates disposed on each main surface side other than one main surface on which electrodes of the two substrates are formed. A plate and liquid crystal molecules of a predetermined array under any voltage applied state give a second retardation to the transmitted light which cancels and compensates a first retardation given to the transmitted light passing through the liquid crystal cell. , And at least one optically anisotropic element having a negative optical anisotropy according to a predetermined arrangement of liquid crystal molecules, which is inserted between at least one polarizing plate and the liquid crystal cell. And the other main surface And a liquid crystal material is an n-type liquid crystal material, wherein the liquid crystal cell has a tilt angle of 80 degrees on one and the other main surfaces. Since it is a liquid crystal cell that has been subjected to a vertical alignment treatment of ≧ °, and the liquid crystal material is an n-type liquid crystal material, a display with a high contrast ratio and no viewing angle dependency was realized. It is possible to provide a liquid crystal display device having a high-speed response that can be realized, for example, an HSN mode LCD.

The angle formed by the direction of the optical axis of each of the plurality of optical anisotropic layers constituting at least one optical anisotropic element and the direction normal to the principal surface is not constant along the direction normal to the principal surface. Therefore, it is possible to cancel and compensate the retardation given to the transmitted light by the liquid crystal molecules of the predetermined arrangement, and thus realize a display having a high contrast ratio and no viewing angle dependence, which can be put to practical use. It is possible to provide a liquid crystal display element having a high speed response.

The arrangement of each of the plurality of optical anisotropic layers constituting at least one optical anisotropic element is such that the liquid crystal molecules of any one of the plurality of optical anisotropic layers have a predetermined arrangement regardless of the order of the optical axes of the optical anisotropic layers. Since the arrays are arranged so as to substantially correspond to the directions of the optical axes, it is possible to cancel and compensate the retardation given to the transmitted light by the liquid crystal molecules of an arbitrary array, and therefore, have a high contrast ratio, and Thus, it is possible to provide a practically applicable high-speed response liquid crystal display device that realizes a display having no viewing angle dependency.

Since the optical axes of the plurality of optical anisotropic layers constituting at least one optical anisotropic element and the optical axes of the liquid crystal molecules in the predetermined arrangement are on the same plane, the liquid crystal molecules in the predetermined arrangement are arranged. A liquid crystal display device with a high-speed response that can be compensated by canceling out the retardation given to the transmitted light and thus has a high contrast ratio and has no viewing angle dependence can do.

The arrangement of the optical axes of the plurality of optical anisotropic layers constituting at least one optical anisotropic element is set according to the twist when the arrangement of the optical axes of the liquid crystal molecules in the predetermined arrangement has a twist. Since the liquid crystal molecules are arranged in a twisted arrangement, it is possible to cancel and compensate the retardation that the liquid crystal molecules in the arrangement give to the transmitted light even when the liquid crystal molecule arrangement has a twist, and therefore a high contrast ratio is obtained. ,And,
It is possible to provide a liquid crystal display element that realizes a display having no viewing angle dependence and that can be put to practical use and has a high-speed response.

The angle formed by the direction of the optical axis of each of the plurality of optical anisotropic layers constituting at least one optical anisotropic element and the normal line direction of the main surface is continuous or along the normal line direction of the main surface. Since it is assumed to change stepwise, the angle formed by the direction of the optical axis of each liquid crystal molecule and the normal direction of the main surface changes continuously or stepwise along the normal direction of the main surface. Even in the case where the liquid crystal molecules can be compensated by canceling the retardation given to the transmitted light, and the direction of the optical axis of each of the plurality of optically anisotropic layers does not matter in which order. If they correspond to the directions of the optical axes of, respectively, similarly,
It is possible to cancel and compensate the retardation that the liquid crystal molecules give to the transmitted light, and therefore, a display having a high contrast ratio and having no viewing angle dependency is realized.
It is possible to provide a liquid crystal display device having a high-speed response that can be put to practical use.

Since the arrangement of the optical axes of each of the plurality of optically anisotropic layers is a change including twist in the direction of the normal to the principal surface, even when the arrangement of the optical axes of the liquid crystal molecules has twist, It is possible to cancel and compensate the retardation that the liquid crystal molecules of the array give to the transmitted light, and therefore, have a high contrast ratio and realize a display that does not depend on the viewing angle. A liquid crystal display device can be provided.

Since the continuous or stepwise change is assumed to be a change from a direction substantially parallel to the normal direction of the principal surface to a direction substantially parallel to the direction including the principal surface, the optical axis of each liquid crystal molecule is changed. The angle between the direction of the main surface and the normal direction of the main surface is continuous or stepwise along the normal direction of the main surface, from a direction substantially parallel to the normal direction of the main surface to a direction including the main surface. Even when changing to the parallel direction, it is possible to cancel and compensate the retardation given to the transmitted light by the liquid crystal molecules of the array, and therefore, have a high contrast ratio and have no viewing angle dependence. It is possible to provide a liquid crystal display device that realizes a display and that can be put to practical use and has a high-speed response.

The direction of the optical axis of each of the plurality of optical anisotropic layers forming at least one optical anisotropic element is substantially parallel to the main surface on one side close to the liquid crystal cell of the optical anisotropic element. Since the other side of the device is assumed to be substantially perpendicular to the main surface, the angle formed by the direction of the optical axis of each liquid crystal molecule and the normal direction of the main surface is continuous or along the normal direction of the main surface. Even in the case where it changes stepwise from a direction substantially parallel to the normal direction of the main surface to a direction substantially parallel to the direction including the main surface,
If the direction of the optical axis of each of the plurality of optically anisotropic layers substantially corresponds to the direction of the optical axis of any liquid crystal molecule in any order, the retardation given to the transmitted light by the liquid crystal molecule is canceled. Therefore, it is possible to provide a liquid crystal display element that can be compensated and has a high contrast ratio and that realizes a display that does not depend on the viewing angle and that can be used for practical purposes and has a high-speed response.

The direction of the optical axis of each of the plurality of optical anisotropic layers forming at least one optical anisotropic element is substantially perpendicular to the main surface on one side close to the liquid crystal cell of the optical anisotropic element. On the other side of the element, since it is assumed to be substantially parallel to the main surface, the angle formed by the direction of the optical axis of each liquid crystal molecule and the normal direction of the main surface is continuous or along the normal direction of the main surface. Even in the case where it changes stepwise from a direction substantially parallel to the normal direction of the main surface to a direction substantially parallel to the direction including the main surface,
If the direction of the optical axis of each of the plurality of optically anisotropic layers substantially corresponds to the direction of the optical axis of any liquid crystal molecule in any order, the retardation given to the transmitted light by the liquid crystal molecule is canceled. Therefore, it is possible to provide a liquid crystal display element that can be compensated and has a high contrast ratio and that realizes a display that does not depend on the viewing angle and that can be used for practical purposes and has a high-speed response.

Since the optical anisotropic element is provided between the one and the other polarizing plates and the liquid crystal cell, the optical axes of the plurality of optical anisotropic layers constituting the one and the other optical anisotropic elements are set. If the directions substantially correspond to the directions of the optical axes of any liquid crystal molecules in any order, it is possible to cancel and compensate the retardation that the liquid crystal molecules give to the transmitted light, and therefore, the high contrast ratio. It is possible to provide a liquid crystal display device having a high-speed response, which has the above-mentioned characteristics and which realizes a display that does not depend on the viewing angle.

Since the optical anisotropic element is provided with one or more uniaxial or biaxial retardation plates in addition to the optical anisotropic element including a plurality of optical anisotropic layers, the optical anisotropic element If the direction of the optical axis of each of the plurality of optically anisotropic layers forming the element or the retardation plate corresponds to the direction of the optical axis of any liquid crystal molecule in any order, the liquid crystal molecule transmits the transmitted light. It is possible to provide a liquid crystal display device having a high contrast ratio and having a high contrast ratio and realizing a display that does not depend on the viewing angle, and which is capable of practical application and has a high-speed response. it can.

Of the two substrates, the liquid crystal layer is provided in a region other than the first substrate neighboring region near one substrate, the second substrate neighboring region near the other substrate, and the first and second substrate neighboring regions. Third
In the liquid crystal molecule alignment in the first predetermined voltage applied state, the alignment direction of some of the liquid crystal molecules in the third region is the normal direction of the main surface. In the liquid crystal molecule array in the second predetermined voltage applied state, the alignment direction of almost all the liquid crystal molecules in the third region is the normal direction of the main surface. Since the liquid crystal molecules are arranged substantially parallel to each other, a liquid crystal display element having a high contrast ratio and realizing a display having no viewing angle dependence, which can be practically used and has a high-speed response, for example, an OCB mode LCD , Π twist cell OCB mode LCD, HAN mode LCD, HSN mode LCD can be provided.

Since some of the liquid crystal molecules are liquid crystal molecules included in the central region of the third region, a display having a high contrast ratio and no viewing angle dependence is realized. Liquid crystal display device capable of high speed response, such as O
CB mode LCD, π twist cell OCB mode LC
A D, HSN mode LCD can be provided.

Since the liquid crystal molecule arrangement is symmetrical with respect to a part of the liquid crystal molecules, it has a high contrast ratio and realizes a display independent of the viewing angle, and has a high-speed response that can be put to practical use. A liquid crystal display device such as an OCB mode LCD, a π twist cell OCB mode LCD, and an HSN mode LCD can be provided.

The display operation is performed in the first predetermined voltage application state and the second predetermined voltage application state.
Since it is performed within an applied voltage range between the predetermined voltage application state and a predetermined voltage application state, it is possible to realize a display having a high contrast ratio and no viewing angle dependency, and a practically applicable high-speed response liquid crystal display element. , OCB mode LCD, π twist cell OCB mode LCD, HAN mode LCD, HS
An N-mode LCD can be provided.

The arrangement of each of the plurality of optical anisotropic layers constituting at least one optical anisotropic element is in any one of the voltage application state between the first predetermined voltage application state and the second predetermined voltage application state. Since it is an array corresponding to the liquid crystal molecule array, it is possible to offset and compensate the retardation that each liquid crystal molecule of the corresponding liquid crystal molecule array gives to the transmitted light, and therefore, have a high contrast ratio, And,
It is possible to provide a liquid crystal display element that realizes a display having no viewing angle dependence and that can be put to practical use and has a high-speed response.

Since the direction of the polarization axis of one of the two polarizing plates and the direction of the polarization axis of the other polarizing plate are perpendicular to each other, the display is turned off. The retardation given to the transmitted light by the liquid crystal molecule arrangement in the voltage applied state is canceled and compensated, or the retardation given by the liquid crystal molecule arrangement in the voltage applied state to the transmitted light is canceled and compensated. By doing so, depending on the display mode of the liquid crystal cell, a display method of normally black mode or normally white mode, which has a high contrast ratio and has no viewing angle dependence, has been realized, and has been put into practical use. It is possible to provide a possible fast response liquid crystal display device, for example, an HSN mode LCD.

[0063]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a principle and a method of achieving an object will be described with reference to the drawings, regarding an embodiment of a liquid crystal display device according to the present invention.

FIG. 1 is a schematic configuration diagram of a first OCB mode LCD according to the present invention. An OCB mode cell including first and second substrates 11 and 12 and a liquid crystal layer 17 sandwiched therebetween, and third and fourth substrates 13 and 14
And a first optical anisotropic cell (optical anisotropic element) composed of an optical anisotropic element 18 sandwiched between them and the fifth and sixth substrates 15 and 16 and sandwiched between them. A second optical anisotropic cell (optical anisotropic element) including an optical anisotropic element 19 is provided, and an OCB mode cell is provided between the first optical anisotropic cell and the second optical anisotropic cell. It is sandwiched between.

Liquid crystal molecules 17a, 17b, 17c, 17d, 17 contained in the liquid crystal layer 17 of the OCB mode cell.
e forms one form of the liquid crystal molecule alignment in the OCB mode, that is, the alignment form in the first predetermined voltage applied state, and the direction of the optical axis of each liquid crystal molecule is the direction indicated by the arrow in the figure. .

Optically anisotropic element 18 of the first optically anisotropic cell
Optically anisotropic layers 18a, 18b, 18c contained therein
And the optically anisotropic layers 19a, 19b and 19c included in the optically anisotropic element 19 of the second optically anisotropic cell, as will be described later, liquid crystal molecules 17a, 17b, 17c and 17.
An array form corresponding to the array form of d and 17e is formed.

FIG. 2 is a schematic configuration diagram of an example of an optically anisotropic cell constituting the liquid crystal display element according to the present invention. FIG.
As shown in (a), this optically anisotropic cell is
And sandwiched between the second substrates 21 and 22 and
The optical anisotropic body LD1, LD2, LD3, and LD4 are composed of a sandwiching layer including an optical anisotropic layer shown by an ellipsoid. Optically anisotropic bodies LD1, LD2, LD that are ellipsoids
3, the minor axes of LD4 are optical axes OL1, OL2, OL3, O
It is L4. That is, the optical anisotropy of the optically anisotropic substance included in the optically anisotropic cell constituting the liquid crystal display element according to the present invention is a negative sign. FIG. 2B is a normal line direction of the first and second substrates 21 and 22 of FIG.
1. Optical anisotropic bodies LD1, LD2, LD3, LD4 from above
It is the figure which looked at. The xyz axes shown in FIGS. 2A and 2B indicate the correspondence of the projection directions.

As shown in FIGS. 2 (a) and 2 (b), the optical anisotropic bodies LD1, LD2, LD3, LD4 have the optical axes OL1, OL2, OL3, OL4, which are the short axes, oriented in one direction. It continuously changes from one substrate to the other substrate. In this way, the direction of the optical axis of the optically anisotropic body is
Depending on the direction of the optical axis of any liquid crystal molecule, it is possible to use different optical anisotropic elements for each part, especially optical anisotropic elements in which the optical axis direction of the optical anisotropic body changes continuously. The main features of the liquid crystal display device according to the present invention are provided.

Returning to FIG. 1, the principle by which a good dark state display (black display) in the normally black mode can be obtained by this configuration will be described. The gist of the objective achievement principle is that the retardation given to the transmitted light of the liquid crystal cell and the optically anisotropic cell by each liquid crystal molecule is determined by the retardation given to the transmitted light by any optically anisotropic layer corresponding to each liquid crystal molecule. To offset and compensate. That is, the retardation by the liquid crystal molecule 17a and the retardation by the optical anisotropic layer 18c, the retardation by the liquid crystal molecule 17b and the retardation by the optical anisotropic layer 18b, the retardation by the liquid crystal molecule 17c and the retardation by the optical anisotropic layers 18a and 19c, and the liquid crystal molecule 17d. The retardation and the retardation of the optically anisotropic layer 19b, and the retardation of the liquid crystal molecules 17e and the retardation of the optically anisotropic layer 19a cancel each other and compensate each other, so that the refractive index ellipsoid of the transmitted light becomes a sphere.

Therefore, when the display portion of the liquid crystal display element is observed from any angle, the inversion region does not exist, and when the two polarizing plates are arranged so that their polarization directions are orthogonal to each other, A good dark state display (black display) with a high contrast ratio can be reliably obtained, and the normally black mode is set at this time. Further, when the retardation due to the liquid crystal molecule alignment in the second predetermined voltage applied state is compensated, a good bright state display (white display) with a high contrast ratio can be obtained, and in this case, normally white It becomes a mode.

Further, the two polarizing plates are arranged so that their respective polarization directions are parallel to each other, and the first or second polarizing plate is arranged.
By compensating the retardation due to the liquid crystal molecule alignment in the state of applying the predetermined voltage, good bright display in normally white mode and good dark state display in normally black mode with high contrast ratio can be obtained respectively.

In the drawing, the liquid crystal molecules and the optically anisotropic layer do not necessarily have a one-to-one correspondence in the displayed number, but it is difficult to make a one-to-one correspondence in reality. Therefore, the final refractive index ellipsoid of the transmitted light becomes almost a sphere, and a desired level of dark state display or bright state display can be obtained no matter which angle the display section of the liquid crystal display element is observed. Correspondence that is possible is sufficient.

FIG. 3 is a schematic configuration diagram of a second OCB mode LCD according to the present invention. An OCB mode cell including first and second substrates 31 and 32 and a liquid crystal layer 37 sandwiched therebetween, and third and fourth substrates 33 and 34.
And a first optically anisotropic cell (optical anisotropic element) composed of an optical anisotropic element 38 sandwiched between them, and fifth and sixth substrates 35 and 36, and an optical anisotropic cell sandwiched between them. A second optical anisotropic cell including an optical anisotropic element 39 (optical anisotropic element), the second optical anisotropic cell is placed on the OCB mode cell, and the second optical anisotropic cell is further mounted. The configuration is such that the first optically anisotropic cell is placed on the isotropic cell.

Liquid crystal molecules 37a, 37b, 37c, 37d, 37 contained in the liquid crystal layer 37 of the OCB mode cell.
As in the case of the first OCB mode LCD of FIG. 1, e is a form of the OCB mode liquid crystal molecular alignment, that is,
The liquid crystal molecules are arranged in the first predetermined voltage application state, and the direction of the optical axis of each liquid crystal molecule is the direction shown by the arrow in the figure.

Optically anisotropic element 38 of the first optically anisotropic cell
Optically anisotropic layers 38a, 38b, 38c contained therein
And the optical anisotropic layers 39a, 39b, 39c included in the optical anisotropic element 39 of the second optical anisotropic cell are as shown in FIG.
Similarly to the case of the first OCB mode LCD of the above, liquid crystal molecules 37a, 37b, 37c, 37d, 37e are as follows.
An alignment form corresponding to the alignment form is formed, and the retardation given to the transmitted light of the liquid crystal cell and the optically anisotropic cell by each liquid crystal molecule is determined by one of the optically anisotropic layers corresponding to each liquid crystal molecule. The retardation applied to the transmitted light cancels and compensates.
That is, the retardation by the liquid crystal molecule 37a and the retardation by the optical anisotropic layer 38a, the retardation by the liquid crystal molecule 37b and the retardation by the optical anisotropic layer 38b, the retardation by the liquid crystal molecule 37c and the retardation by the optical anisotropic layers 38c and 39a, and the liquid crystal molecule 37d. The retardation and the retardation of the optically anisotropic layer 39b, and the retardation of the liquid crystal molecules 37e and the retardation of the optically anisotropic layer 39c cancel each other to compensate each other, so that the refractive index ellipsoid of the transmitted light becomes a sphere.

Therefore, as in the case of the first OCB mode LCD, no inversion region exists when observing the display section of the liquid crystal display element from any angle, and the two polarizing plates are polarized in mutually opposite directions. In the case of being arranged so as to be orthogonal to, it is possible to surely obtain a good dark state display (black display) having a high contrast ratio, and at this time, the normally black mode is set. Further, when the retardation due to the liquid crystal molecule alignment in the second predetermined voltage applied state is compensated, a good bright state display (white display) with a high contrast ratio can be obtained, and in this case, normally white It becomes a mode.

Further, the two polarizing plates are arranged so that their polarization directions are parallel to each other, and the first or second polarizing plate is arranged.
By compensating the retardation due to the liquid crystal molecule alignment in the state of applying the predetermined voltage, good bright display in normally white mode and good dark state display in normally black mode with high contrast ratio can be obtained respectively.

The above-mentioned first and second OCs of FIGS. 1 and 3
As can be seen from the description of the B-mode LCD, in order to achieve the object of the present invention, the retardation imparted to the transmitted light by each liquid crystal molecule may be canceled and compensated by any of the optically anisotropic layers. That is, FIG.
Alternatively, in the configuration of FIG. 3, the first optically anisotropic cell and the second optically anisotropic cell
The optically anisotropic cell of FIG.
In the above structure, both the first and second optically anisotropic cells may be arranged below the liquid crystal cell.
The first optically anisotropic cell and the second optically anisotropic cell may be replaced with each other in a state in which the optically anisotropic cell is placed below the liquid crystal cell. Alternatively, the first and second optically anisotropic cells may be replaced by a single optically anisotropic cell and arranged above or below the liquid crystal cell. Furthermore, the optical axis of the optically anisotropic layer in the optically anisotropic element does not necessarily have to change continuously. Further, as the alignment form of the liquid crystal molecules for compensating the retardation, any alignment form from the first predetermined voltage applied state to the second predetermined voltage applied state is selected, and the direction of the optical axis of the optically anisotropic layer is It may be configured so as to correspond to the direction of the optical axis of the liquid crystal molecule.

In the above OCB mode LCD structure, even when the liquid crystal cell is replaced with the π-twist cell described above, the retardation imparted to the transmitted light by each liquid crystal molecule is canceled by any of the optically anisotropic layers and compensated. With such a configuration, it is possible to similarly improve the display state in any of the predetermined voltage application states in each configuration.

FIG. 4 shows a HAN mode LCD according to the present invention.
FIG. First and second substrates 41 and 42
And a liquid crystal layer 45 sandwiched therebetween.
A mode cell and an optically anisotropic cell (optical anisotropic element) composed of the third and fourth substrates 43 and 44 and an optical anisotropic element 46 sandwiched therebetween are provided on the HAN mode cell. The configuration is such that an optically anisotropic cell is placed.

Liquid crystal molecules 45a, 45b, 45c, 45d, 45 contained in the liquid crystal layer 45 of the HAN mode cell.
e forms one form of HAN mode liquid crystal molecule alignment, that is, the alignment form in the first predetermined voltage application state (including no voltage application state), and the direction of the optical axis of each liquid crystal molecule is as shown in FIG. This is the direction indicated by the arrow inside.

Optical anisotropic layers 46a, 46b, 46c, 46 included in the optical anisotropic element 46 of the optically anisotropic cell.
d and 46e are liquid crystal molecules 45a and 45e as follows.
b, 45c, 45d, and 45e are formed in an array form corresponding to the array form, and each liquid crystal molecule gives to the transmitted light of the liquid crystal cell and the optically anisotropic cell as in the case of the LCD in the OCB mode or the like. The retardation obtained is offset and compensated by the retardation given to the transmitted light by any of the optically anisotropic layers corresponding to each liquid crystal molecule. That is, the retardation by the liquid crystal molecule 45a and the retardation by the optical anisotropic layer 46a, the retardation by the liquid crystal molecule 45b and the retardation by the optical anisotropic layer 46b, the retardation by the liquid crystal molecule 45c and the retardation by the optical anisotropic layer 46c, and the retardation by the liquid crystal molecule 45d. The retardation due to the optically anisotropic layer 46d, the retardation due to the liquid crystal molecules 45e and the retardation due to the optically anisotropic layer 46e are mutually offset and compensated, whereby the refractive index ellipsoid of the transmitted light becomes a sphere.

Therefore, even in the case of this HAN mode LCD, there is no inversion region when observing the display portion of the liquid crystal display element from any angle, and the two polarizing plates have their polarization directions orthogonal to each other. In such a case, a good dark state display (black display) with a high contrast ratio can be reliably obtained, and the normally black mode is set at this time. In this case, the retardation of the liquid crystal layer gradually decreases as the applied voltage is increased, and the birefringence effect is due only to the optically anisotropic element, so that light is transmitted and a bright state display (white display) Can be obtained. Even when light is incident on the substrate surface from an oblique direction, the retardation due to the liquid crystal cell is canceled by the optical anisotropic element and compensated, so that a good dark state with a sufficient contrast ratio can be observed from any direction. You can get the display. Therefore, inversion of the image and the like are prevented, and good display can be obtained. Further, when the retardation due to the liquid crystal molecule alignment in the second predetermined voltage applied state is compensated, a good bright state display (white display) with a high contrast ratio can be obtained, and in this case, normally white It becomes a mode.

Further, the two polarizing plates are arranged so that their polarization directions are parallel to each other, and the retardation due to the liquid crystal molecule alignment in the first predetermined voltage applied state or the second predetermined voltage applied state is compensated. If you try
A good normally white mode bright state display and a normally black mode dark state display each having a high contrast ratio can be obtained.

Even in the case of the above HAN mode LCD, in order to achieve the object of the present invention, if the retardation imparted to the transmitted light by each liquid crystal molecule is canceled and compensated by any of the optically anisotropic layers. good. That is, the optically anisotropic cell may be arranged on either the upper side or the lower side of the liquid crystal cell, and the optical axis of the optically anisotropic layer in the optically anisotropic element does not necessarily have to change continuously. .
Further, as the alignment form of the liquid crystal molecules for compensating the retardation, any alignment form from the first predetermined voltage applied state to the second predetermined voltage applied state is selected, and the direction of the optical axis of the optically anisotropic layer is It may be configured so as to correspond to the direction of the optical axis of the liquid crystal molecule.

FIG. 5 shows an HSN mode LCD according to the present invention.
FIG. First and second substrates 51 and 52
And the liquid crystal layer 57 sandwiched between these and the HSN
A mode cell, a first optically anisotropic cell (optical anisotropic element) composed of the third and fourth substrates 53 and 54, and an optical anisotropic element 58 sandwiched between them; Second optical anisotropic cell (optical anisotropic element) composed of substrates 55 and 56 of No. 6 and an optical anisotropic element 59 sandwiched therebetween.
And the HSN mode cell is mounted on the second optically anisotropic cell, and the first optically anisotropic cell is further mounted on the HSN mode cell.

Liquid crystal molecules 57a, 57b, 57c, 57d, 57 contained in the liquid crystal layer 57 of the HSN mode cell.
e and 57f are the same as the above-mentioned HAN mode LCD.
One form of the N-mode liquid crystal molecule alignment, that is, the alignment form in the first predetermined voltage application state (including the voltage non-application state) is formed, and the direction of the optical axis of each liquid crystal molecule is indicated by an arrow in the figure. Is the direction indicated by.

Optically anisotropic element 58 of the first optically anisotropic cell
Optically anisotropic layers 58a, 58b, 58c contained therein
And the optically anisotropic layers 59a, 59b, 59c included in the optically anisotropic element 59 of the second optically anisotropic cell are the same as in the case of each mode LCD described above, as described below.
7a, 57b, 57c, 57d, 57e, and 57f are formed in an array form corresponding to the array form, and the retardation given to the transmitted light of the liquid crystal cell and the optically anisotropic cell by each liquid crystal molecule It is configured to cancel and compensate by the retardation given to the transmitted light by any of the corresponding optically anisotropic layers. That is, the retardation by the liquid crystal molecule 57a and the retardation by the optical anisotropic layer 58a, the retardation by the liquid crystal molecule 57b and the retardation by the optical anisotropic layer 58b, the retardation by the liquid crystal molecule 57c and the retardation by the optical anisotropic layer 58c, and the retardation by the liquid crystal molecule 57d. The retardation due to the optical anisotropic layer 59a, the retardation due to the liquid crystal molecules 57e and the retardation due to the optical anisotropic layer 59b, the retardation due to the liquid crystal molecules 57f and the retardation due to the optical anisotropic layer 59c are mutually offset and compensated, so that the transmitted light The index ellipsoid of is a sphere.

Therefore, as in the case of the above-mentioned LCDs of each mode, no inversion region exists when observing the display portion of the liquid crystal display element from any angle, and the polarization directions of the two polarizing plates are orthogonal to each other. In such a case, a good dark state display (black display) with a high contrast ratio can be reliably obtained, and the normally black mode is set at this time. Further, when the retardation due to the liquid crystal molecule alignment in the second predetermined voltage applied state is compensated, a good bright state display (white display) with a high contrast ratio can be obtained, and in this case, normally white It becomes a mode.

Further, two polarizing plates are arranged so that their respective polarization directions are parallel to each other, and the first or second polarizing plate is arranged.
By compensating the retardation due to the liquid crystal molecule alignment in the state of applying the predetermined voltage, good bright display in normally white mode and good dark state display in normally black mode with high contrast ratio can be obtained respectively.

Even in the case of this HSN mode LCD, in order to achieve the object of the present invention, the retardation given to the transmitted light by each liquid crystal molecule may be canceled by any of the optically anisotropic layers and compensated. That is,
In the structure of FIG. 5, the first optically anisotropic cell and the second optically anisotropic cell may be interchanged, and both the first and second optically anisotropic cells are above or below the liquid crystal cell. May be disposed on the side of the liquid crystal cell, and the first and second optically anisotropic cells may be disposed on the upper side or the lower side of the liquid crystal cell.
The optically anisotropic cell and the second optically anisotropic cell may be replaced with each other. Alternatively, the first and second optically anisotropic cells may be replaced by a single optically anisotropic cell and arranged above or below the liquid crystal cell. Furthermore, the optical axis of the optically anisotropic layer in the optically anisotropic element does not necessarily have to change continuously. Further, as the alignment form of the liquid crystal molecules for compensating the retardation, any alignment form from the first predetermined voltage applied state to the second predetermined voltage applied state is selected, and the direction of the optical axis of the optically anisotropic layer is It may be configured so as to correspond to the optical axis of the liquid crystal molecule.

Although the first OCB mode LCD has been described above, the liquid crystal molecules and the optically anisotropic layers are required to have a one-to-one correspondence in any of the above-mentioned mode LCDs. There is no. In reality, it is difficult to make a perfect one-to-one correspondence, and the final refractive index ellipsoid of transmitted light is almost spherical, which is required regardless of the angle at which the display section of the liquid crystal display element is observed. Correspondence that is sufficient to obtain a dark state display or a bright state display of a certain level is sufficient.

The above embodiments of the present invention have been described with respect to the case where the liquid crystal molecule array that gives the retardation to be compensated has no twist. The effect of the present invention can be obtained by setting the arrangement of the optically anisotropic layers so that the retardation given to (1) is canceled and compensated by any of the optically anisotropic layers. Further, although the above-described embodiments of the present invention have been described with respect to a transmissive liquid crystal display device utilizing a birefringence effect, the configuration of the present invention can be applied to a reflective liquid crystal display device. When applied to a reflective liquid crystal display element, light incident on the liquid crystal cell passes through a distance twice the liquid crystal layer thickness. It can be halved, and further improvement in response speed can be expected.

[0094]

EXAMPLES Examples to which the structure of the liquid crystal display device according to the present invention is applied will be described in detail below. The basic configuration of each embodiment is almost the same as the configuration of the OCB mode LCD of FIG. 6 or a partially modified configuration.

The first embodiment is an OCB mode LC shown in FIG.
The configuration is almost the same as that of D, but the liquid crystal cell is similar to that shown in FIG.
The π-twist cell similar to that shown in is adopted.

Amorphous silicon TF on a glass substrate
A TFT array substrate having T (thin film transistor) and a scanning line such as a gate line, a signal line, and a pixel electrode, each having 3 pixels, 480 pixels in the vertical direction and 640 pixels in the horizontal direction, and each pixel of the TFT array substrate A color filter having a black matrix pattern corresponding to the above and a colored portion of three primary colors of red, green, and blue, and an opposite substrate on which an ITO electrode was formed were used for a liquid crystal cell. SE-5211 is formed as an alignment film on the main surfaces of the TFT array substrate and the counter substrate.
(Product name (manufactured by Nissan Kagaku Co., pretilt angle about 5
)) Was applied to a thickness of 80 nm and formed. Here, the pixel pitch is 0.33 mm in length and 0.11 mm in width. Then, rubbing treatment was performed on the alignment films formed on the two substrates. The rubbing directions of the two substrates are parallel to each other and also to the scanning line.

Next, as a spacer, Micropearl SP (trade name (manufactured by Sekisui Fine Chemical Co., Ltd.)), which is a spherical fine particle having a diameter of 7.1 μm, was dispersed at a density of 80 particles / mm 2 on the main surface of one substrate. . XN-21 (trade name (manufactured by Mitsui Toatsu Chemicals, Inc.)) as an epoxy resin adhesive is screen-printed on the peripheral portion of the effective display area of the other substrate except for a portion which becomes an opening for liquid crystal injection. After application by the method, the TFT array substrate and the counter substrate were superposed so that the alignment films face each other, and were heated and bonded while being pressed to fabricate a liquid crystal cell having a cell gap of 7.1 μm. ZLI-113 as a liquid crystal composition was added to the liquid crystal cell.
2 (trade name (manufactured by E. Merck, retardation value Δ
n = 0.14 nm)) as a chiral agent in S811
A liquid crystal material added with (product name (manufactured by E. Merck)) is injected by a vacuum injection method, and after injection, the liquid crystal injection port is sealed with an ultraviolet curable resin UV-1000 (product name (manufactured by Sony Kekamil)). I stopped. At this time, the concentration of the chiral agent in the liquid crystal material was adjusted so that the chiral pitch of the liquid crystal molecule alignment was about 35 μm.

The viewing angle compensating liquid crystal cell which is an optically anisotropic cell has a liquid crystal cell structure in which a liquid crystal layer is interposed between two transparent substrates. SiO2 was obliquely vapor-deposited on the opposite surfaces of the two substrates at different angles. A discotic liquid crystal having a negative optical anisotropy in a liquid crystal layer which is an optically anisotropic element sandwiched between these two substrates (a C18H having an alkyl chain with an ester bond in a triphenylene nucleus).
6 (OCOC7 H15) 6) is introduced as an optically anisotropic layer, and the pretilt angle is 10 ° for the substrate near the driving liquid crystal cell and 80 ° for the substrate far away. There is. The retardation value Δnd in the direction normal to the substrate surface of the liquid crystal cell used as the optically anisotropic cell is −50 nm. In order to compensate the retardation when the display of this liquid crystal cell is turned on,
As shown in FIG. 1, the viewing angle compensating liquid crystal cells were arranged above and below the driving liquid crystal cell, respectively, and their alignment directions were arranged so as to make an angle of 180 ° with the arrangement direction of the driving liquid crystal cells. The viewing angle compensating liquid crystal cell is arranged so that the substrate surface having a small pretilt angle is in contact with the driving liquid crystal cell as described above.

Further, G1220DU (trade name (manufactured by Nitto Denko Corporation)) is used as a polarizing plate on the outer side of each optically anisotropic cell, and the optical axis of the polarizing plate is the substrate on which the polarizing plate is arranged. The two polarizing plates were attached so that the optical axes of the two polarizing plates were perpendicular to each other.

The π twist cell OCB mode TFT-LCD obtained as described above had a uniform 180 ° twist orientation when no voltage was applied.
When a voltage was applied to the π twist cell OCB mode TFT-LCD and the liquid crystal cell was driven with a voltage at which the effective retardation value was about 100 nm as the minimum drive voltage within the range of the rising state, Electro-optical characteristics were obtained in which the transmittance monotonously decreased with application of a drive voltage, a front-side contrast ratio of 100 or more was obtained, and the viewing angle was wide. Regarding the response speed, there was almost no difference between gradations, which was as high as about 5 ms, and even if a moving image was displayed, the outline was not blurred and a good display could be obtained.

As a second embodiment, both of the two optically anisotropic cells in the first embodiment are arranged on the side of the counter substrate on which the color filter is formed. In the first embodiment, T
The optical anisotropic cell arranged on the FT array substrate side is
It is moved to the counter substrate side without changing the direction with respect to the substrate normal direction. Also in the π twist cell OCB mode TFT-LCD according to the second embodiment, it is possible to obtain the response speed, the viewing angle characteristic and the contrast ratio which are equivalent to those of the first embodiment.

As a comparison target of the above-mentioned first or second embodiment, a π twist cell OCB mode TFT-LCD which is the first comparison example was manufactured. The first comparative example uses two uniaxial retardation plates (optical anisotropic elements) instead of the two optically anisotropic cells, and otherwise the same members and conditions as those of the first embodiment. And The first obtained in this way
Twist cell OCB mode TFT-L according to the comparative example of
In the case of a CD, a black display is obtained in front of the display portion, that is, in the direction normal to the surface of the substrate, but the display inversion region is extremely wide when observed with the viewing angle changed, and the contrast ratio is remarkably lowered. .

In the third embodiment, the retardation value Δnd of the optically anisotropic cell in the first embodiment is -280 nm.
The liquid crystal cell is configured so as to compensate for retardation when the display is turned off.
Π twist cell OCB with the same members and conditions as in the embodiment of
A mode TFT-LCD was produced. The π twist cell OCB mode T according to the third embodiment thus obtained
When the FT-LCD is displayed in normally black,
The response was fast and the viewing angle characteristics were good.

The fourth embodiment is the same as the first embodiment, except that
In addition to the one optically anisotropic cell, one biaxial retardation plate (optical anisotropic element) was arranged on the side of the counter substrate on which the color filter was formed, and the liquid crystal cell was an OCB mode cell. In the structure of the fourth embodiment, the compensation of the retardation in the central region of the liquid crystal layer is performed by the biaxial retardation plate (optical anisotropic element), and the compensation of the retardation in the region near the substrate of the liquid crystal layer is performed by two optical anisotropies. Configured to do with a directional cell,
Other than that, OCB was performed with the same members and conditions as in the first embodiment.
A mode TFT-LCD was produced. The OCB mode TFT-LCD according to the fourth embodiment thus obtained
The viewing angle characteristics were further improved as compared with the first embodiment. The same effect can be obtained when two uniaxial retardation plates are used in combination instead of the biaxial retardation plate.

In the fifth embodiment, the alignment film on the counter substrate on which the color filter is formed in the first embodiment is an alignment film for vertical alignment (ODS-E (trade name (manufactured by Chisso))),
The spacer is a micropearl having a diameter of 3.6 μm, and the retardation value Δnd of the optically anisotropic cell to be arranged is 50 nm.
And the liquid crystal cell is a HAN mode cell, the retardation is compensated when the display of the liquid crystal cell is turned on, and otherwise the same members and conditions as those of the first embodiment are used. HAN mode TFT
-LCD was made.

When a voltage was applied to this HAN mode TFT-LCD, electro-optical characteristics were obtained in which the transmittance monotonously decreased as the applied voltage increased, and a front contrast ratio of 100 or more was obtained. The range was wide. The response speed has almost no difference between gradations and is as high as about 5 ms, and even if a moving image is displayed, the outline is not blurred and a good display can be obtained.

As a second comparative example, two uniaxial retardation plates (optical anisotropic elements) were used in place of the two optically anisotropic cells in the fourth example, and the other four were used. An OCB mode TFT-LCD was produced by using the same members and conditions as those in the above example. O according to the second comparative example thus obtained
In the CB mode TFT-LCD, a black display is obtained in front of the display part, that is, in the direction normal to the substrate surface, but the inversion area of the display when observing while observing the viewing angle is very wide, and the contrast ratio is high. Also fell significantly.

[0108]

As described above, according to the liquid crystal display element of the present invention, the liquid crystal which performs the display operation within the range of the applied voltage in which the liquid crystal molecules included in the central region of the liquid crystal layer are in a substantially raised state. The display element is provided with a second retardation for the transmitted light that cancels and compensates the first retardation that the liquid crystal molecules in a predetermined array under any voltage applied state imparts to the transmitted light transmitted through the liquid crystal cell. In addition, since at least one of the polarizing plate and the liquid crystal cell is inserted and arranged, at least one optical anisotropic element having a negative optical anisotropy according to a predetermined arrangement of liquid crystal molecules is provided, A liquid crystal display device having a high contrast ratio and realizing a display that does not depend on the viewing angle and that can be practically used and has a high-speed response, such as an OCB mode LCD and a π twist cell OCB mode LC. , It can be provided HAN mode LCD, the HSN mode LCD.

Since the angle between the optical axis direction of each of the plurality of optical anisotropic layers constituting at least one optical anisotropic element and the normal line direction of the principal surface is not constant, liquid crystal molecules of a predetermined arrangement are arranged. A liquid crystal display device with a high-speed response that can be compensated by canceling out the retardation given to the transmitted light and thus has a high contrast ratio and has no viewing angle dependence can do.

The arrangement of the plurality of optical anisotropic layers constituting at least one optical anisotropic element is such that the liquid crystal molecules of any of the plurality of optical anisotropic layers have a predetermined arrangement regardless of the order of the optical axes of the optical anisotropic layers. Since the arrays are arranged so as to substantially correspond to the directions of the optical axes, it is possible to cancel and compensate the retardation given to the transmitted light by the liquid crystal molecules of an arbitrary array, and therefore, have a high contrast ratio, and Thus, it is possible to provide a liquid crystal display device that realizes a display that does not depend on the viewing angle and that can be put to practical use and has a high-speed response.

Since the optical axes of the plurality of optical anisotropic layers forming at least one optical anisotropic element and the optical axes of the liquid crystal molecules in the predetermined arrangement are in the same plane, the liquid crystal molecules in the predetermined arrangement are arranged. A liquid crystal display element with a high-speed response that can be compensated for by canceling the retardation given to transmitted light and thus has a high contrast ratio and has no viewing-angle dependence can do.

The arrangement of the optical axes of the plurality of optical anisotropic layers constituting at least one optical anisotropic element is set according to the twist when the arrangement of the optical axes of the liquid crystal molecules in the predetermined arrangement has a twist. Since the liquid crystal molecules are arranged in a twisted arrangement, it is possible to cancel and compensate the retardation that the liquid crystal molecules in the arrangement give to the transmitted light even when the liquid crystal molecule arrangement has a twist, and therefore a high contrast ratio is obtained. ,And,
It is possible to provide a liquid crystal display element that realizes a display having no viewing angle dependence and that can be put to practical use and has a high-speed response.

The angle formed by the direction of the optical axis of each of the plurality of optical anisotropic layers constituting at least one optical anisotropic element and the direction normal to the principal surface is continuous or along the direction normal to the principal surface. Since it is assumed to be changed stepwise, the angle formed by the direction of the optical axis of each liquid crystal molecule and the normal direction of the main surface changes continuously or stepwise along the normal direction of the main surface. Even when the liquid crystal molecules can be compensated by canceling the retardation given to the transmitted light, the direction of the optical axis of each of the plurality of optically anisotropic layers is any liquid crystal molecule If they correspond to the directions of the optical axes of, respectively, similarly,
It is possible to cancel and compensate the retardation that the liquid crystal molecules give to the transmitted light, and therefore, a display having a high contrast ratio and having no viewing angle dependency is realized.
It is possible to provide a liquid crystal display device having a high-speed response that can be put to practical use.

Since the arrangement of the optical axes of each of the plurality of optically anisotropic layers is a change including twist with respect to the direction normal to the principal surface, even when the arrangement of the optical axes of the liquid crystal molecules has twist, It is possible to cancel and compensate the retardation that the liquid crystal molecules of the array give to the transmitted light, and therefore, have a high contrast ratio and realize a display that does not depend on the viewing angle. A liquid crystal display device can be provided.

Since the continuous or stepwise change is assumed to be a change from a direction substantially parallel to the normal direction of the main surface to a direction substantially parallel to the direction including the main surface, the optical axis of each liquid crystal molecule is changed. The angle between the direction of the main surface and the normal direction of the main surface is continuous or stepwise along the normal direction of the main surface, from a direction substantially parallel to the normal direction of the main surface to a direction including the main surface. Even when changing to the parallel direction, it is possible to cancel and compensate the retardation given to the transmitted light by the liquid crystal molecules of the array, and therefore, have a high contrast ratio and have no viewing angle dependence. It is possible to provide a liquid crystal display device that realizes a display and that can be put to practical use and has a high-speed response.

The direction of the optical axis of each of the plurality of optical anisotropic layers forming at least one optical anisotropic element is substantially parallel to the main surface on one side close to the liquid crystal cell of the optical anisotropic element. Since the other side of the device is assumed to be substantially perpendicular to the main surface, the angle formed by the direction of the optical axis of each liquid crystal molecule and the normal direction of the main surface is continuous or along the normal direction of the main surface. Even in the case where it changes stepwise from a direction substantially parallel to the normal direction of the main surface to a direction substantially parallel to the direction including the main surface,
If the direction of the optical axis of each of the plurality of optically anisotropic layers substantially corresponds to the direction of the optical axis of any liquid crystal molecule in any order, the retardation given to the transmitted light by the liquid crystal molecule is canceled. Therefore, it is possible to provide a liquid crystal display element that can be compensated and has a high contrast ratio and that realizes a display that does not depend on the viewing angle and that can be used for practical purposes and has a high-speed response.

The direction of the optical axis of each of the plurality of optical anisotropic layers forming at least one optical anisotropic element is substantially perpendicular to the main surface on one side close to the liquid crystal cell of the optical anisotropic element. On the other side of the element, since it is assumed to be substantially parallel to the main surface, the angle formed by the direction of the optical axis of each liquid crystal molecule and the normal direction of the main surface is continuous or along the normal direction of the main surface. Even in the case where it changes stepwise from a direction substantially parallel to the normal direction of the main surface to a direction substantially parallel to the direction including the main surface,
If the direction of the optical axis of each of the plurality of optically anisotropic layers substantially corresponds to the direction of the optical axis of any liquid crystal molecule in any order, the retardation given to the transmitted light by the liquid crystal molecule is canceled. Therefore, it is possible to provide a liquid crystal display element that can be compensated and has a high contrast ratio and that realizes a display that does not depend on the viewing angle and that can be used for practical purposes and has a high-speed response.

Since the optical anisotropic element is provided between the one and the other polarizing plates and the liquid crystal cell, the optical axes of the plurality of optical anisotropic layers constituting the one and the other optical anisotropic elements are adjusted. If the directions substantially correspond to the directions of the optical axes of any liquid crystal molecules in any order, it is possible to cancel and compensate the retardation given to the transmitted light by the liquid crystal molecules, and thus the high contrast ratio. It is possible to provide a liquid crystal display device having a high-speed response, which has the above-mentioned characteristics and which realizes a display that does not depend on the viewing angle.

Since the optical anisotropic element is provided with at least one uniaxial or biaxial retardation plate in addition to the optical anisotropic element containing a plurality of optical anisotropic layers, the optical anisotropic element If the direction of the optical axis of each of the plurality of optically anisotropic layers forming the element or the retardation plate corresponds to the direction of the optical axis of any liquid crystal molecule in any order, the liquid crystal molecule transmits the transmitted light. It is possible to provide a liquid crystal display device having a high contrast ratio and having a high contrast ratio and realizing a display that does not depend on the viewing angle, and which is capable of practical application and has a high-speed response. it can.

The liquid crystal layer is provided in a region other than the first substrate neighboring region near one of the two substrates, the second substrate neighboring region near the other substrate, and the first and second substrate neighboring regions. Third
In the liquid crystal molecule alignment in the first predetermined voltage applied state, the alignment direction of some of the liquid crystal molecules in the third region is the normal direction of the main surface. In the liquid crystal molecule array in the second predetermined voltage applied state, the alignment direction of almost all the liquid crystal molecules in the third region is the normal direction of the main surface. Since the liquid crystal molecules are arranged substantially parallel to each other, a liquid crystal display element having a high contrast ratio and realizing a display having no viewing angle dependence, which can be practically used and has a high-speed response, for example, an OCB mode LCD , Π twist cell OCB mode LCD, HAN mode LCD, HSN mode LCD can be provided.

Since some of the liquid crystal molecules are liquid crystal molecules included in the central region of the third region, a display having a high contrast ratio and no viewing angle dependence is realized. Liquid crystal display device capable of high speed response, such as O
CB mode LCD, π twist cell OCB mode LC
A D, HSN mode LCD can be provided.

Since the liquid crystal molecules are arranged symmetrically with respect to some of the liquid crystal molecules, a display having a high contrast ratio and no viewing angle dependence is realized, and a high-speed response that can be put to practical use is realized. A liquid crystal display device such as an OCB mode LCD, a π twist cell OCB mode LCD, and an HSN mode LCD can be provided.

The display operation is performed in the first predetermined voltage application state and the second predetermined voltage application state.
Since it is performed within an applied voltage range between the predetermined voltage application state and a predetermined voltage application state, it is possible to realize a display having a high contrast ratio and no viewing angle dependency, and a practically applicable high-speed response liquid crystal display element. , OCB mode LCD, π twist cell OCB mode LCD, HAN mode LCD, HS
An N-mode LCD can be provided.

The arrangement of each of the plurality of optical anisotropic layers constituting at least one optical anisotropic element is in any one of the voltage application state between the first predetermined voltage application state and the second predetermined voltage application state. Since it is an array corresponding to the liquid crystal molecule array, it is possible to offset and compensate the retardation that each liquid crystal molecule of the corresponding liquid crystal molecule array gives to the transmitted light, and therefore, have a high contrast ratio, And,
It is possible to provide a liquid crystal display element that realizes a display having no viewing angle dependence and that can be put to practical use and has a high-speed response.

The liquid crystal cell is a liquid crystal cell in which the alignment treatment on one main surface is a tilt alignment treatment and the alignment treatment on the other main surface is a vertical alignment treatment. It is possible to provide a practicable high-speed response liquid crystal display device, for example, a HAN mode LCD, which realizes a display having a high contrast ratio and no viewing angle dependency.

Since the liquid crystal cell is a liquid crystal cell in which vertical alignment processing with a tilt angle of 80 ° or more is performed on one and the other main surface, and the liquid crystal material is an n-type liquid crystal material, a high contrast is obtained. It is possible to provide a practically applicable high-speed response liquid crystal display element, for example, an HSN mode LCD, which has a display ratio and has a viewing angle-independent display.

Since the direction of the polarization axis of one of the two polarizing plates and the direction of the polarization axis of the other polarizing plate are perpendicular to each other, the display is turned off. The retardation given to the transmitted light by the liquid crystal molecule arrangement in the voltage applied state is canceled and compensated, or the retardation given by the liquid crystal molecule arrangement in the voltage applied state to the transmitted light is canceled and compensated. By doing so, depending on the display mode of the liquid crystal cell, a display method of normally black mode or normally white mode, which has a high contrast ratio and has no viewing angle dependence, has been realized, and has been put into practical use. It is possible to provide a possible fast response liquid crystal display device, for example, an HSN mode LCD.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first OCB mode LCD according to the present invention.

FIG. 2 is a schematic configuration diagram of an example of an optically anisotropic cell that constitutes a liquid crystal display element according to the present invention.

FIG. 3 is a schematic configuration diagram of a second OCB mode LCD according to the present invention.

FIG. 4 is a schematic configuration diagram of a HAN mode LCD according to the present invention.

FIG. 5 is a schematic configuration diagram of an HSN mode LCD according to the present invention.

FIG. 6 is a schematic configuration diagram of an OCB mode LCD.

FIG. 7 is an explanatory diagram schematically showing the alignment of liquid crystal molecules in the liquid crystal layer of the OCB mode LCD in each voltage application state.

FIG. 8 is a π cell (pi) which is the basis of the OCB mode LCD.
Explanatory diagram schematically showing an alignment of liquid crystal molecules in a liquid crystal layer in each voltage application state of (cell).

FIG. 9 is a schematic configuration diagram of a HAN mode cell.

FIG. 10 is a schematic configuration diagram of an HSN mode cell.

[Explanation of symbols]

11, 21, 31, 41, 51, 61, 71, 81, 9
1, 101 First substrate 12, 22, 32, 42, 52, 62, 72, 82, 9
2, 102 Second substrate 13, 33, 43, 53 Third substrate 14, 34, 44, 54 Fourth substrate 15, 35, 55 Fifth substrate 16, 36, 56 Sixth substrate 17, 37 , 45, 57, 67, 73, 83, 93, 1
03 liquid crystal layers 17a-17e, 37a-37e, 45a-45e, 5
7a-57f, 73a-73e, 83a-83e, 93
a-93c, 103a-103c Liquid crystal molecules 73A, 73C, 83A, 83C Liquid crystal layer substrate vicinity area 73B, 83B Liquid crystal layer central area 18, 19, 38, 39, 46, 58, 59 Optical anisotropic element 18a-18c, 19a -19c, 38a-38c, 3
9a-39c, 46a-46e, 58a-58c, 59
a-59c Optical anisotropic layer LD1-LD4 Optical anisotropic body OL1-OL4 Optical axis 60 OCB mode cell 60P Liquid crystal molecule arrangement plane 61R, 62R Alignment direction (rubbing direction) 63, 64 Polarizing plate 65, 66 Phase difference plate (optical) Anisotropic element)

[Procedure amendment]

[Submission date] January 25, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Fig. 8

[Correction method] Change

[Correction contents]

FIG. 8 is an explanatory view schematically showing the liquid crystal molecule alignment in the liquid crystal layer in each voltage application state of the π twist cell OCB mode LCD.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Masato Shoko, Inventor Masato Shoko, 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Incorporated, Toshiba Yokohama Works (72) Inventor Kiyoshi Shobara 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Address Incorporated company Toshiba Yokohama Office (72) Inventor Hitoshi Hato 8 Shinsita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture Incorporated company Toshiba Yokohama Office

Claims (20)

[Claims] 1. A pair of substrates, each of which has an electrode formed on one main surface thereof and which constitutes a liquid crystal cell, and said one main surface on which said electrodes are formed, are arranged so as to face each other. A liquid crystal layer sandwiched between two substrates and made of a liquid crystal material containing a nematic liquid crystal composition as liquid crystal molecules; and a main surface side other than the one main surface on which the electrodes of the two substrates are formed. Two polarizing plates respectively arranged, and a second retardation for canceling out and compensating for the first retardation given to the transmitted light which the liquid crystal molecules of a predetermined arrangement under any voltage applied state transmit through the liquid crystal cell. At least one of the polarizing plates and the liquid crystal cell is inserted and disposed so as to provide the transmitted light with at least one negative optical anisotropy according to the predetermined arrangement of the liquid crystal molecules. Two optics And a Motoko Ho, a liquid crystal display device and performing a display operation in the range of the applied voltage the liquid crystal molecules is substantially upstanding state contained in the central region of the liquid crystal layer. 2. An electrode is formed on one main surface of each of the two substrates, which constitutes a liquid crystal cell, and the one main surface on which the electrode is formed is arranged so as to face each other. A liquid crystal layer sandwiched between two substrates and made of a liquid crystal material containing a nematic liquid crystal composition as liquid crystal molecules; and a main surface side other than the one main surface on which the electrodes of the two substrates are formed. Two polarizing plates respectively arranged, and a second retardation for canceling out and compensating for the first retardation given to the transmitted light which the liquid crystal molecules of a predetermined arrangement under any voltage applied state transmit through the liquid crystal cell. Is provided between at least one of the polarizing plates and the liquid crystal cell so as to impart to the transmitted light, and at least 1 having a negative optical anisotropy according to the predetermined arrangement of the liquid crystal molecules. Two optics And a Motoko Ho, the liquid crystal cell, one of the two substrates, the alignment treatment on one main surface of one of said substrate is tilted orientation treatment,
A liquid crystal display element, wherein the alignment treatment on the one main surface of the other substrate is a liquid crystal cell which has been subjected to a hybrid alignment treatment which is a vertical alignment treatment. 3. An electrode is formed on one main surface of each of the substrates, and two substrates forming a liquid crystal cell are arranged to face each other so that the one main surface on which the electrode is formed faces each other. A liquid crystal layer sandwiched between two substrates and made of a liquid crystal material containing a nematic liquid crystal composition as liquid crystal molecules; and a main surface side other than the one main surface on which the electrodes of the two substrates are formed. Two polarizing plates respectively arranged, and a second retardation for canceling out and compensating for the first retardation given to the transmitted light which the liquid crystal molecules of a predetermined arrangement under any voltage applied state transmit through the liquid crystal cell. Is provided between at least one of the polarizing plates and the liquid crystal cell so as to impart to the transmitted light, and at least 1 having a negative optical anisotropy according to the predetermined arrangement of the liquid crystal molecules. Two optics The liquid crystal cell is a liquid crystal cell in which vertical alignment processing with a tilt angle of 80 ° or more is performed on the one main surface of one side and the other side, and the liquid crystal material is an n-type liquid crystal material. A liquid crystal display device characterized by the above. 4. The liquid crystal display element according to claim 1, wherein the direction of the optical axis of each of the plurality of optical anisotropic layers constituting at least one of the optical anisotropic elements and the method of the principal surface. The liquid crystal display element is characterized in that an angle formed by the line direction is not constant along a direction normal to the main surface. 5. The liquid crystal display element according to claim 1, wherein a plurality of optical anisotropic layers forming at least one of the optical anisotropic elements are arranged in the plurality of optical anisotropic layers. A liquid crystal display element, wherein the directions of the optical axes of the layers are arranged substantially corresponding to the directions of the optical axes of the liquid crystal molecules in any one of the predetermined arrangements regardless of the order. 6. The liquid crystal display element according to claim 1, wherein at least one of the plurality of optical anisotropic layers constituting the optical anisotropic element and each liquid crystal in the predetermined arrangement are arranged. A liquid crystal display device characterized in that the optical axis of the molecule is in the same plane. 7. The liquid crystal display element according to claim 1, wherein the optical axes of a plurality of optical anisotropic layers constituting at least one of the optical anisotropic elements are arranged in the predetermined array. When the arrangement of the optical axes of the liquid crystal molecules has a twist, the arrangement is set according to the twist. 8. The liquid crystal display element according to claim 1, wherein the direction of the optical axis of each of the plurality of optical anisotropic layers constituting at least one of the optical anisotropic elements and the method of the principal surface. A liquid crystal display element, wherein an angle formed by the line direction is continuously or stepwise changed along the normal direction of the main surface. 9. The liquid crystal display device according to claim 8,
The liquid crystal display element, wherein the arrangement of the optical axes of each of the plurality of optically anisotropic layers is a change including a twist with respect to a normal direction of the main surface. 10. The liquid crystal display element according to claim 8, wherein the continuous or stepwise change is from a direction substantially parallel to a normal direction of the main surface to a direction including the main surface. A liquid crystal display device characterized in that the change is in a direction substantially parallel to. 11. The liquid crystal display element according to claim 1, wherein the optical axes of a plurality of optical anisotropic layers forming at least one of the optical anisotropic elements are the optical anisotropic layers. A liquid crystal display element, characterized in that one side of the element close to the liquid crystal cell is substantially parallel to the main surface, and the other side of the optical anisotropic element is substantially perpendicular to the main surface. 12. The liquid crystal display element according to claim 1, wherein the optical axes of a plurality of optical anisotropic layers forming at least one of the optical anisotropic elements are the optical anisotropic layers. A liquid crystal display element, wherein one side of the element close to the liquid crystal cell is substantially perpendicular to the main surface, and the other side of the optically anisotropic element is substantially parallel to the main surface. 13. A liquid crystal display device according to claim 1, wherein the optical anisotropic element is provided between the one and the other polarizing plates and the liquid crystal cell. Display element. 14. The liquid crystal display element according to claim 1, wherein the optical anisotropic element includes one or more uniaxial elements in addition to the optical anisotropic element including the plurality of optical anisotropic layers. A liquid crystal display device comprising a biaxial or biaxial retardation plate. 15. The liquid crystal display element according to claim 1, or 4 to 12, wherein the liquid crystal layer includes a first substrate vicinity region in the vicinity of one of the two substrates and the other. A second substrate vicinity region in the vicinity of the first substrate and the first substrate
And a third region other than the second substrate vicinity region, the liquid crystal molecule alignment in the first predetermined voltage applied state is such that a part of the liquid crystal molecules included in the third region is The alignment direction of the liquid crystal molecules is substantially parallel to the normal direction of the main surface, and the liquid crystal molecule alignment in the second predetermined voltage applied state is almost the same as that of the liquid crystal molecules included in the third region. A liquid crystal display device, characterized in that all liquid crystal molecules have a liquid crystal molecule alignment in which the alignment direction is substantially parallel to the normal line direction of the main surface. 16. The liquid crystal display element according to claim 15, wherein the part of the liquid crystal molecules is a liquid crystal molecule included in a central region of the third region. 17. The liquid crystal display element according to claim 16, wherein the liquid crystal molecules are arranged symmetrically with respect to the part of the liquid crystal molecules. 18. The liquid crystal display element according to claim 15, wherein the display operation is within an applied voltage range between the first predetermined voltage applied state and the second predetermined voltage applied state. Liquid crystal display device characterized by being performed. 19. The liquid crystal display element according to claim 15, wherein a plurality of optical anisotropic layers forming at least one of the optical anisotropic elements are arranged so that the first predetermined voltage is applied. A liquid crystal display device having an arrangement corresponding to a liquid crystal molecule arrangement in a voltage application state between any one of the states and the second predetermined voltage application state. 20. The liquid crystal display device according to claim 1, wherein the direction of the polarization axis of one of the two polarizing plates and the direction of the polarization axis of the other polarizing plate are , A liquid crystal display device characterized in that the directions are at right angles to each other.