JPH09197429A - Liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a display element having high-speed responsiveness and wide visual field angle. SOLUTION: The electrodes 11, 12 (12a, 12b) of upper and lower substrates forming one pixel are formed to a shape obtd. by lining up plural fine stripe conductive parts 11a, 12a apart the spacings of non-conductor parts 11b, 12b and disposing the conductor parts 11a, 12a of the electrodes 11, 12 of the upper and lower substrates by shifting these parts from each other to form a diagonal electric field E in a liquid crystal layer 15 held by the electrodes 11, 12 by which the liquid crystal alignment in the plane direction of the substrates is controlled. Plural layers of such diagonal electric field forming liquid crystal layers 15 are superposed and arranged as guest-host liquid crystal layers including dichromatic dyes.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystal display device controlled by an oblique electric field.

[0002]

2. Description of the Related Art Liquid crystal display devices have the great advantages of thinness, light weight, and low power consumption. Therefore, they are positively used as display devices for personal OA equipment such as Japanese word processors and disk top personal computers. It is used for.
Most of the liquid crystal display elements (hereinafter abbreviated as LCD) use nematic liquid crystal, and the display system is a birefringence mode.
It can be roughly divided into two types, a mode and a rotation mode.

An LCD of a birefringence mode display system using a twisted nematic liquid crystal is, for example, an LCD (called an ST system) having a molecular arrangement twisted by 180 ° or more and has steep electro-optical characteristics. Even if there is no switching element (thin film transistor or diode) for each pixel, a large capacity display can be easily obtained by time division driving.

However, the above-mentioned ST method has a slow response speed of several hundred milliseconds and a narrow viewing angle characteristic, and is not suitable for an application product requiring high display performance.

On the other hand, since the LCD of the optical rotation mode has a molecular arrangement twisted by 90 ° (called the TN system) and exhibits a high contrast ratio, a clock, a calculator, and a switching element are provided for each pixel. Thus, it is possible to realize an LCD (for example, TFT-LCD) having a large display capacity and high contrast and high display performance.

In recent years, this TN type TFT-LCD performs gradation display, but when observed obliquely, such phenomena as display reversal, blackout, and white spots occur. Therefore, the viewing angle characteristic is extremely narrow.

Further, as the TN type TFT-LCD has become higher in quality, it has come to be used also in large-sized and extremely high-definition applied products such as desktop monitors. When applied to such fields and high-definition TV applications, an extremely fast response speed is required, but when the gradation display is performed in the TN method, the response time required for pattern rewriting is 100 ms at maximum. And slow.

In addition, this TN system requires an operating voltage of 4 to 5 v in order to obtain high contrast characteristics, and consumes high power.

As a means for improving the viewing angle characteristics of the above-mentioned TN method, the viewing angle dependence is improved by using a liquid crystal display element in which two regions in which one liquid crystal molecule rises (pretilt direction) is different by 180 ° are provided in one pixel. Method (Two Domain
TN: Abbreviated as TDTN For example, JP-A-64-8852
No. 0) or a domain-divided TN (DDTN abbreviated as Y.Koi) using a spray arrangement to obtain the same effect as TDTN.
ke, et.al., 1992, SID, p798) etc. have been proposed. The purpose of these is to effectively eliminate the above-mentioned extreme value by defining two regions having different viewing angle dependences of the applied voltage-transmittance characteristic as one pixel.

However, in these methods, the resist is patterned in order to change the pretilt direction within a fine region.
Patterning and mask exposure are required to perform rubbing and rubbing, or to form two types of alignment films (surface condition and material) in a fine region, and the number of steps is increased compared to general TN method steps. It is not practical because the cost is extremely high.

Further, although the above-mentioned extreme value can be eliminated in a certain viewing angle range, the viewing angle characteristic is an average characteristic of the individual characteristics of the two regions having different viewing angle dependences, and there is no extreme depending on the viewing angle direction. I can't. As for the contrast, since the bad characteristic and the good characteristic are averaged, the average characteristic is obtained, and the contrast is lower than that of the good characteristic alone. The response speed is the same as that of the conventional TN method.

On the other hand, Y. Yamaguchi et al. Apply a voltage to a nematic liquid crystal layer having a non-twisted splay alignment and, as a bend alignment, generate liquid crystal molecules within the applied voltage range that maintains this bend alignment. Birefringence effect type liquid crystal display mode: OCB in which the tilt state is controlled by the applied voltage value and the phase difference in the liquid crystal layer is controlled by the voltage
Mode (= Optically Compensate
d Birefringence mode (Y. Yamaguchi, et al. SID93 DIGES)
T, pp 277-280). Also, Boss et al. Have proposed a similar liquid crystal display mode (P. Bos, et al. SID'83).
DIGEST, pp30-31).

The liquid crystal molecule arrangement of this OCB mode is characterized in that the upper half and the lower half of the liquid crystal layer are always symmetrical. Therefore, even if the viewing angle (observation angle) is tilted to the left and right directions of the display screen, the viewing angle characteristics are symmetrical.
Further, by arranging the biaxial retardation plate, the composite refractive index ellipsoid of the liquid crystal layer and the biaxial retardation plate becomes a sphere in a certain voltage state, that is, there is no three-dimensional refractive index anisotropy. Since it is an optical medium, by generating a phase difference in the horizontal direction from this state, it becomes possible to perform voltage control in which the phase difference changes from 0 to ½ wavelength at various viewing angles, and the above-mentioned viewing angle dependence is almost eliminated. There is no display mode.

As described above, the OCB mode is excellent in terms of viewing angle characteristics such as the gradation performance and the contrast performance described above. However, in the OCB mode, it is necessary to transfer the liquid crystal molecule arrangement from the splay arrangement (no voltage applied state) to the bend arrangement by applying a voltage, which requires strong energy, and in fact It was necessary to apply a voltage higher than the driving voltage (after). Although a TFT is required for high-capacity and high-definition display, the voltage cannot be applied by this TFT element, and the OCB mode cannot be used for high-capacity and high-definition display. In addition, the time required for the transfer takes one minute or more, and it takes time to start up the display.

In the OCB mode, it is necessary to maintain the bend arrangement (prevent the transition to the spray arrangement), and for this purpose, it is necessary to constantly apply a certain voltage to all the modulation sections. is there. In order to lower the driving voltage of the device as much as possible, it is necessary to set the voltage for maintaining the bend arrangement to the lower limit of the driving voltage range. In this case, the bend arrangement needs to be stably maintained at this applied voltage.
However, the applied voltage with which the bend arrangement is stably maintained is as high as about 2.5 V, resulting in a high drive voltage.

Further, in order to obtain a sufficient contrast, an operating voltage of 5 to 8 V is required, and the power consumption is extremely high.

Further, there is a problem of temperature characteristics that the display characteristics are deteriorated because the retardation of the liquid crystal phase changes in a high temperature state. Further, in production, it is necessary to control the pretilt angles of the upper and lower substrates completely symmetrically, and the margin of unevenness of the pretilt angle in the plane is narrow. Therefore, there is also a problem that the yield is low.

On the other hand, Oe et al. Formed In-pla on one side of the substrate to form an electrode to which an electric field can be applied in the plane direction of the substrate and change the alignment direction of liquid crystal molecules in the plane direction of the substrate.
By improving the ne mode, we have proposed a TFT array consisting of a simple electrode structure and a TFT-LCD with a 45 ° molecular arrangement change like SSFLC (M, Oh-e, et.al. "Principle
s and Characteristics of Electro-Optical Behaiviou
r In-Plane Switching Mode ", ASIA DISPLAY '95 DIGEST
PAPER p577-580, 1995): IPS mode.

This IPS mode, like SSFLC, changes the alignment direction of liquid crystal molecules in the plane direction of the substrate, and the retarder
Since the optical axis causing the distortion is controlled by the electric field, the viewing angle characteristics of the gradation display performance and the contrast performance described above are extremely wide. However, the response speed is slow because it is strongly influenced by the alignment regulating force (anchoring) of the liquid crystal molecules. Further, the operating voltage is as high as 7 V and the power consumption is extremely high. Further, in principle, liquid crystal molecules on the electrodes cannot be changed, so that the light cannot be deviated on the electrodes, and the electrodes must be made of a light-shielding metal. Therefore, TFT-LCD
As a result, the aperture ratio becomes low and the display brightness becomes extremely dark.

[0020]

As described above, the conventional display mode has problems such as viewing angle characteristics, response speed, driving voltage (power consumption), display brightness, temperature characteristics, etc., all of which are satisfied. There was no LCD to do.

The present invention solves the problems of the conventional display mode, and provides a novel display mode of extremely excellent quality.
The purpose is to propose a configuration of the code.

[0022]

First, the present invention provides a liquid crystal display device in which a plurality of pixels are formed by sandwiching a liquid crystal layer between opposed first and second substrates each having an electrode,
The electrodes of the substrate are formed by juxtaposing a plurality of narrow conductor portions for each pixel with a non-conductor portion interposed therebetween, and the electrodes of the first substrate and the electrodes of the second substrate are formed on one substrate. At least a part of the conductor portion of the electrode and the non-conductor portion of the electrode of the other substrate are arranged to face each other, the liquid crystal layer is at least two liquid crystal layers, and the liquid crystal layer is a dichroic dye. In a guest-host liquid crystal layer or a homogeneously aligned liquid crystal.

FIG. 1 shows a conceptual plan view of an electrode used in the present invention. (A) and (b) are counter substrates serving as upper and lower substrates,
It is a conceptual diagram which shows the electrode structure of 1 pixel of an array substrate. As shown in the figure, the electrode 11 on the counter substrate is the narrow conductor portion 1
1a and non-conductive material portions 11b are alternately arranged, and the conductive material portions 11a have a structure in which the non-conductive material portions 11b are arranged in parallel with each other.

Similarly, for the electrodes 12 on the array substrate,
The conductor portion 12a and the non-conductor portion 12b are formed. The electrodes shown in the figure are linear arrays, but they may be curved.

When these upper and lower substrates are combined, at least a part of these electrodes has a cell structure in which the conductor portion and the non-conductor portion face each other. Due to the structure, an oblique electric field is applied to the liquid crystal layer. The present invention is basically characterized in that the display is performed by changing the arrangement of liquid crystal molecules by the oblique electric field.

FIG. 2 shows the cell structure of the liquid crystal display device of the present invention. (A) is a perspective view showing a combined arrangement of the electrode structures of the upper and lower substrates 10a, 10b, (b) is a sectional view thereof, (c) is an electric field E applied to the liquid crystal layer 15 by the electrodes, and A cell cross-sectional view showing an arrangement state of the liquid crystal molecules 15a by the electric field is shown. 1 and 2
As shown in (a) and (b), the upper and lower substrates 10a and 10b
The electrodes 11 and 12 of are the fine and narrow conductor portion 1 for each pixel.
1a, 12a and a plurality of non-conductor parts 11b, 12b are formed in parallel, and each electrode has a ladder-type pattern in which the conductor parts are conductively connected at the ends for each pixel. Conductor part 11
The width of a and 12a is EL, and the width of the non-conductor part is SS.

When the upper and lower substrates are opposed to each other and the combined liquid crystal layer is sandwiched to form a cell, the conductor portion 11a of the electrode 11 of the upper substrate 10a becomes the non-conductor portion 12b of the electrode 12 of the lower substrate 10b.
Are arranged in parallel so as to face each other, and are provided so that the conductor portions 11a and 12a of the electrodes on the upper and lower substrates are offset from each other.

Therefore, as shown in FIG. 2C, an oblique electric field E can be applied to the liquid crystal molecules 15a. As shown in (c), the liquid crystal molecules 15a change their alignment state in the direction of the electric field due to the oblique electric field E thereof. When the molecules are aligned in a certain direction on the substrate surface, that is, when the initial alignment state of the homogeneous alignment state is not the direction of the oblique electric field, the liquid crystal molecules rotate at a slight tilt with respect to the cell plane direction from the initial state, as shown in (c). Change to a different state.

FIG. 3 shows an example of a conceptual view of the cell plane of the liquid crystal display device of the present invention. (A) shows the initial alignment state of the liquid crystal layer 15, and (b) shows the state after a sufficient voltage is applied. In order to obtain the initial alignment state, as shown in FIG. 2B, alignment curtains 13, 14 are formed on the upper and lower substrates 10a, 10b.
Is applied and rubbing is performed. In FIG. 3, as shown in FIG. 3A, the substrate surface is rubbed from the lower left side to the upper right side of the figure to align the liquid crystal molecules 15a of the liquid crystal layer 15.

An oblique electric field E (FIG. 2C) is applied to the liquid crystal layer 15 from the conductor portion of one substrate to the conductor portion of the other substrate. Therefore, when observing the liquid crystal cell from the cell normal direction, the liquid crystal molecules rotate in the cell plane as shown in the figure. When a polarizer (polarizing plate) having a crossed Nicols is combined with this liquid crystal cell so as to display black in the initial state, a birefringence effect is produced by applying a voltage. In this case, the highest transmitted light intensity can be obtained by inclining the liquid crystal molecules by 45 ° from the absorption axis of the polarizing plate. Therefore, assuming that the liquid crystal molecules are completely oriented in the direction of the electric field by applying a voltage, the highest transmitted light can be obtained by inclining the orientation direction by 45 ° from the electrode direction in the initial state.

FIG. 4 illustrates the first liquid crystal display element of the present invention. The oblique electric field forming cells 101, 102 described above are shown.
2 shows a liquid crystal display element in which two layers are stacked. The feature of the liquid crystal cell of the present invention is that an oblique electric field is applied as described above. Therefore, as shown in the figure, the conductor parts 11a, 12
The liquid crystal molecules 15a are inclined in the opposite directions a and b for each a. In order to obtain a wide viewing angle, it is necessary to compensate for the tilt. Therefore, as shown in the figure, the cell 101
If the conductor portion 12b of the electrode of the lower substrate is butted against the conductor portion 11a of the electrode of the upper substrate of the cell 102, and the cells 101 and 102 are stacked in two layers so that the inclination is reversed, that is, the inclination direction By setting the direction c to a and the direction d to the tilt direction b, the tilt is compensated and a wide viewing angle is obtained.

The present invention is also characterized in that at least one layer of the liquid crystal cell is mixed with a dichroic dye.

FIG. 5 shows the structure of the liquid crystal display device of the present invention in which a dichroic dye is mixed in the liquid crystal cell. An optical configuration of Voff when no voltage is applied and Von when no voltage is applied is shown in (a), a plan view of a liquid crystal cell is shown in (b), and a sectional view of a liquid crystal display device of the present invention is shown in (c). The simplest structure of the liquid crystal display device of the present invention containing a dichroic dye as a display device is, as shown in FIG. 5A, one polarizing plate (polarizer) 18 and the oblique electric field liquid crystal cell 20. Composed by. By the absorption of light by the dichroic dye of the liquid crystal cell and the absorption by the polarizing plate 18,
Controls transmitted light. At VOFF, the intersection angle between the liquid crystal alignment direction 20a of the cell 20 and the polarizing plate absorption axis 18a is θ, whereas at Von, the liquid crystal alignment direction 20b becomes parallel and parallel. Reference numeral 16 indicates a retardation plate.

(B) shows the alignment state of liquid crystal molecules. Vof
In the initial state of f, the liquid crystal molecules 15a and the dichroic dyes 15b of the liquid crystal layer 15 are connected to the conductor portion 1 as shown in the figure.
It is oriented in the extension direction of 1a and 12a. When the dielectric anisotropy of the liquid crystal molecules is positive, when a voltage is applied, the liquid crystal molecules 15a are aligned in the electric field E direction like Von, and the liquid crystal molecules are oriented in the direction orthogonal to the conductor direction.

As shown in FIG. 5A, the absorption axis 18a of the polarizing plate and the initial alignment state 20a of the liquid crystal molecules are arranged so as to be orthogonal to each other. In the state Voff where no voltage is applied from the power source V, the light polarized by the polarizing plate 18 is
It is absorbed by the dichroic dye 15b of the liquid crystal cell and, for example, displays black. When a voltage is applied (Von), the liquid crystal layer 1
An oblique electric field is formed at 5 and the liquid crystal molecules rotate 90 °, and are oriented in the same direction as the absorption axis 18a of the polarizing plate 18. for that reason,
One of the polarized components comes to be transmitted, and a bright state is obtained. Thus, the liquid crystal display element of the present invention in which the dichroic dye is mixed can be composed of one liquid crystal cell 20 and one polarizing plate 18.

FIG. 6 shows a liquid crystal molecule 15a and a dichroic dye 15b.
A configuration is shown in which two liquid crystal cells mixed with are combined.
(A) is an upper cell and (b) is a lower cell. As shown in the figure, in the initial state, the orientation directions of the liquid crystal molecules are made orthogonal to each other and the directions of the conductor portions are made to coincide with each other. In the initial state, the liquid crystal molecules are arranged so as to be orthogonal to each other, so that both polarized light components are absorbed, resulting in a dark state,
By applying a voltage, the liquid crystal molecules are aligned in the alignment direction, so that one polarized component is transmitted and becomes a bright state.

The present invention is further characterized in that, among the liquid crystal layers constituting the liquid crystal display element, the molecular arrangement of at least two layers is arranged orthogonally in the cell plane direction.

FIG. 7 shows an optical configuration of the liquid crystal display device of the present invention in which two layers of liquid crystal cells 32 and 33 are stacked between polarizing plates 30 and 31 with absorption axes 30a and 31a orthogonal to each other. (A) shows an initial state and (b) shows a state after voltage application. In the initial state, the liquid crystal layers of the two liquid crystal cells are in the orthogonal alignment state 32a,
33a, the absorption axis 30 of the polarizing plates 30 and 31.
It is arranged orthogonal to or parallel to a and 31a. Therefore, the display is black in the initial state.

In the voltage application state of (b), the alignments 32a and 33a of the liquid crystal layer are parallel to each other and intersect the absorption axes 30a and 31a of the polarizing plate at an angle of 45 °. A bright state can be obtained by adjusting the retardation values of the liquid crystal layer. In this way, it is possible to display on the liquid crystal display element in which the molecular arrangement of the two layers is orthogonal. Also,
This liquid crystal display device has a wider viewing angle by using the structure shown in FIG.

The present invention is further characterized in that a dichroic dye is mixed in two liquid crystal layers arranged orthogonally. FIG. 8 shows a plan view in which a dichroic dye is mixed in the liquid crystal layer of the two-layer cells 40 and 41 in which the stripe directions 11A and 11B of the electrodes are orthogonally arranged. (A) shows the initial state,
The state of voltage application is shown in (b). In the initial state, the liquid crystal molecules in both liquid crystal layers are aligned in one direction, so that light can be transmitted and the light state can be obtained. Further, by applying a voltage, the alignment directions of the liquid crystal molecules are made orthogonal to each other. Since each cell absorbs one polarization component,
It becomes dark.

The present invention is further characterized in that at least three of the liquid crystal layers are liquid crystal layers in which dichroic dyes of yellow (Y), magenta (M) and cyan (C) are mixed.

In the liquid crystal cell of the present invention shown in FIG. 9, (a)
The initial state is shown in (b), and the voltage application state is shown in (b). As shown in the figure, the dichroic dye 15b is rotated by the applied voltage together with the liquid crystal molecules 15a, and the arrangement is changed in parallel to the electrode in the initial state and in the direction orthogonal to the electrode by the voltage application.
Therefore, the transmitted light of the dichroic dye can be controlled.

Green is displayed when Y and C are transmitted, blue is displayed when C and M are transmitted, and red is displayed when M and Y are transmitted. White is displayed when all the transmitted light is transmitted, and black is displayed when all the dichroic dyes are transmitted. Further, by combining the intermediate states, full color display becomes possible.

The present invention is further characterized in that an analyzer for a polarizer is added to the liquid crystal display element for full color display.

The present invention further provides a liquid crystal display element in which a plurality of pixels are formed by sandwiching a liquid crystal layer between two opposed substrates each having an electrode, and in each of the substrates, the electrodes are thinned for each pixel. When the cross-sectional shape of the substrate is viewed, the arrangement is E.
When L, SS, EL, SS ... are alternately arranged, and the conductor portion EL of one substrate and the non-conductor portion SS of the other substrate face each other at least in part and a voltage is applied between the electrodes. Has a cell structure in which an oblique electric field is formed in the liquid crystal layer, and the liquid crystal layer contains a dichroic dye,
In addition, one polarizing plate is arranged.

The liquid crystal display device of the present invention has the cell structure shown in FIG. 5 and one polarizing plate 18 is arranged.

The present invention further provides a liquid crystal display device in which a plurality of pixels are formed by sandwiching a liquid crystal layer between two opposed substrates each having an electrode, and in each of the substrates, the electrode is thin for each pixel. When the cross-sectional shape of the substrate is viewed, the arrangement is E.
L, SS, EL, SS ... Are alternately arranged, and a voltage is applied between electrodes in which the conductor portion EL of one substrate and the non-conductor portion SS of the other substrate are at least partially opposed to each other. The cell structure is such that an oblique electric field is sometimes formed in the liquid crystal layer, and the one substrate is provided with a reflective layer.

The liquid crystal display device of the present invention can be realized without using a polarizing plate by stacking two layers of liquid crystal cells even if it is of a reflective type.

The present invention is further characterized in that in the above liquid crystal display element, one polarizing plate is arranged. When the polarizing plate and the liquid crystal molecule direction of the liquid crystal display device of the present invention are set at an angle of 45 ° with the polarizing plate in the initial state and the retardation thereof is set to λ / 4, a dark state is obtained, and the polarization axis when a voltage is applied. A bright state can be obtained by making the absorption axes of liquid crystal molecules coincide with each other.

The present invention is further characterized in that in the above liquid crystal display element, a dichroic dye is mixed in the liquid crystal layer and one polarizing plate is arranged. Display can be performed if the absorption axis of the polarizing plate and the alignment of the liquid crystal molecules can be changed to 0 or 90 ° under a specific voltage state.

The present invention is further characterized in that the liquid crystal layer is vertically aligned in the initial state.

The present invention is further characterized in that it is an active matrix substrate having switching elements such as TFTs and TFDs on at least one substrate.

At least one of the substrates has a color filter.

As shown in FIG. 10, according to the present invention, since an oblique electric field can be formed on a pixel-by-pixel basis, the lower substrate 10 can be formed.
This is suitable for a structure in which the switching element 17 is arranged using b as an active matrix substrate.

It is also easy to form the color filter 19 on the upper substrate 10a side, for example.

In the present invention, when the refractive index of the conductor portion is n1, the refractive index of the non-conductor portion is n2, and the thickness of the conductor portion is d, 440 ≦ | (n1-n2 ) × d | ≦ 660 (nm), n1, n2, and d are set.

When the refractive index of the conductor portion and the refractive index of the non-conductor portion are different, a diffraction grating is formed. Generally, a transparent conductor is used for the conductor portion, and a liquid crystal layer is inserted in the non-conductor portion, so that the refractive index is different and the diffraction grating is formed.
Therefore, the light is diffracted by the stripe electrode even in the initial state, and the initial transmittance is lowered. At this time, the light intensity of the diffraction grating is I to sin ((n1-n
2) · d / λ · π). (Where n1, n
2 is the refractive index, d is the film thickness, and λ is the wavelength of the transmitted light. Therefore, in order to eliminate light diffraction, (n1-n2) ·
It suffices that d / λ is an almost integer. Practically, (n1−n2) · d = λ (1).

Therefore, as described above, when the refractive index of the conductor portion is n1, the refractive index of the non-conductor portion is n2, and the thickness of the conductor portion is d, the condition of equation (1) is satisfied. If n1, n2 and d are set, no diffraction grating is formed.

Further, in the present invention, in the liquid crystal display device having a color filter, the wavelength of the transmitted light of each pixel is λ1, the refractive index of the conductor portion is n1, the refractive index of the non-conductor portion is n2, When the thickness of the conductor portion is d, n1, n2, and d are set for each pixel so that 0.8 × λ1 ≦ | (n1-n2) × d | ≦ 1.2 × λ1. It is characterized by setting.

[0060]

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

(Embodiment 1) FIGS. 1 to 3 show a liquid crystal display device of this embodiment.

A COM substrate I having a black matrix made of chrome formed on the entire non-pixel portion as the upper substrate 10a.
Using a TO patterning glass substrate, a switching element 17 composed of a TFT is used as the lower substrate 10b (see FIG. 1).
The glass substrate with (b)) was used. Pixel electrode 1 on the lower substrate
ITO is used for 2 similarly to the upper substrate. Then, as shown in the drawing, the pixel electrodes 11 and 12 are formed on the conductor portion 11 on both substrates.
a and 12a and non-conductor parts 11b and 12b are patterned in a stripe shape. The electrode interval is 5 μm for the width EL of the conductor and 15 μm for the width SS of the non-conductor.
Is a striped electrode.

Using such a substrate, the alignment films 13 and 14 are formed.
Polyimide (AL-3046 manufactured by Nippon Synthetic Rubber Co., Ltd.)
(Pretilt angle measurement value 3 °)) was applied and formed, and a rubbing process was performed in the stripe electrode direction. At this time, the rubbing directions of the upper and lower substrates were antiparallel. Then, as a substrate spacing agent on the lower substrate side, the liquid crystal layer thickness was 8.0 μm, and microparticles (particle size 8.0 μm) manufactured by Sekisui Fine Chemical Co., Ltd. were dispersed at a density of 100 particles / mm ^2. A liquid crystal layer 1 made of a nematic liquid crystal material (ZLI-1132 (Δn = 0.14) manufactured by Merck Japan Co., Ltd.) having positive dielectric anisotropy between the substrates, which is sprayed by a dry spraying method.
5 was sandwiched to obtain a liquid crystal cell. Black 2 for this liquid crystal material
2 wt% of color dye (LA103 / 4: manufactured by Mitsubishi Chemical Co., Ltd.)
Is mixed in.

Next, one polarizing plate 18 was placed above the cell. At this time, the absorption axis of the polarizing plate is oriented in a direction forming an angle of 90 ° with the electrode direction.

The model of the molecular arrangement viewed from the substrate normal direction is as shown in FIG. (A) shows the initial state, and (b) shows the molecular alignment state after voltage application. The rubbing direction is a homogeneous arrangement in the electrode direction.

As shown in FIG. 5, in the initial state of the liquid crystal array 20a, the liquid crystal array 20a is uniformly aligned in the direction orthogonal to the absorption axis 18a of the polarizing plate. Therefore, the transmitted light polarized by the polarizing plate is absorbed by the liquid crystal layer 15, and the transmitted light intensity becomes almost zero.

When a voltage is applied to this cell, the liquid crystal is aligned in the direction of the electric field, and when a sufficient voltage is applied, the array state 20b as shown in FIG. 5B is obtained.
As shown in (b), when a voltage is applied to the liquid crystal molecules, the oblique electric field of the liquid crystal molecules is 0 ° from the extension direction of the conductor parts in the non-conductor parts, but it goes toward 90 °. . The absorption axis 18a of the polarizing plate 18 is 90 degrees with respect to the electrodes.
Since the angle is in the direction of °, the absorption axis of the polarizing plate and the absorption direction of the liquid crystal layer coincide with each other as a voltage is applied, and light of one polarization direction is transmitted. Then, the maximum contrast is obtained when a sufficient voltage is applied and the arrangement state as shown in FIG.

A voltage was applied to the thus obtained liquid crystal display device of this embodiment through the TFT 17 to measure the electro-optical characteristics (transmittance-applied voltage curve), and the viewing angle characteristics were measured. Also, when the viewing angle of this liquid crystal display device was measured, a contrast of 10: 1 or more was obtained in a region of 50 ° in all directions.

When the response time was measured, a high-speed response with a rising time of 6 ms and a falling time of 9 ms could be obtained.

As described above, the liquid crystal display element of this embodiment can provide a liquid crystal display element having a high-speed response, a high contrast and a wide viewing angle.

(Embodiment 2) Two liquid crystal cells were stacked as shown in FIG. 6 to form a liquid crystal display element of this embodiment. The cell was manufactured in the same manner as in Embodiment 1, and the angle was set to 45 ° with respect to the electrode direction only in the rubbing direction. The molecular sequence model is as shown in the conceptual diagram of FIG. (A) shows an upper cell and (b) shows a lower cell. As shown in the figure, in the initial state, the liquid crystal molecules are arranged in two cells in the orthogonal direction. Therefore, one polarization direction is absorbed by one cell, and the transmitted light intensity becomes zero.

When a voltage is applied to this cell, the liquid crystal molecules are switched in the directions shown by the arrows in FIG. Therefore, the liquid crystal molecules 15a are arranged so that both upper and lower cells form an angle of 90 ° with respect to the electrodes 11 and 12. Therefore, light is transmitted.

A voltage was applied to the thus obtained liquid crystal display element of the present embodiment through the TFT in the same manner as above, and various characteristics were measured. The transmittance, contrast, viewing angle and response time were measured. Good characteristics were obtained.

(Embodiment 3) As an alignment film, an alignment agent for vertical alignment (ODS-E: manufactured by Chisso) was formed on both substrates, and a liquid crystal display element was formed in the same manner as in Embodiment 1 above.

A voltage was applied to the thus obtained liquid crystal display device of the present embodiment through the TFT in the same manner as described above, and various characteristics were measured. With respect to the transmittance, the contrast, the viewing angle and the response time, Good characteristics were obtained.

(Embodiment 4) As an alignment film, an alignment agent for vertical alignment (ODS-E: manufactured by Chisso) is formed on both substrates, and two cells are laminated so that electrodes are orthogonal to each other, and other conditions are applied. A liquid crystal display device was manufactured in the same manner as in the above example.

A voltage was applied to the thus obtained liquid crystal display device of the present embodiment through the TFT in the same manner as described above, and various characteristics were measured. With respect to the transmittance, the contrast, the viewing angle, and the response time, Good characteristics were obtained.

(Embodiment 5) As a dichroic dye, a liquid crystal display element of the present embodiment was constructed by stacking three cells each using three colors of yellow, magenta and cyan as liquid crystal cells. The cell was manufactured in the same manner as in Embodiment 1, and only the rubbing direction was at an angle of 0 ° with respect to the electrode direction. Further, no color filter is formed on the counter substrate. Then, the absorption axis of the polarizing plate was aligned with the electrode direction.

As a material for the yellow dichroic dye, G-23
2 (manufactured by Nippon Senshoku Co., Ltd.) was used to mix 1 w% into nematic liquid crystal.

As a material for the magenta dichroic dye, G-17
6 (manufactured by Japan Sensitive Dye) was used to mix 1% by weight into nematic liquid crystal.

SI-49 is used as a material for cyan dichroic dye.
7 (manufactured by Mitsui Toatsu Co., Ltd.) was used to mix 1% by weight into nematic liquid crystal.

A voltage was applied to the thus obtained liquid crystal display device of this embodiment through a TFT in the same manner as described above, and various characteristics were measured. The transmittance, contrast, viewing angle and response time were measured. Good characteristics were obtained.

(Embodiment 6) The film thickness of the conductor portion is set to 1250.
The liquid crystal display element was manufactured in the same manner as in Embodiment 1 except that the thickness was set to nm. Since ITO is used for the conductor portion and the refractive index n1 is 2.0 and the non-conductor portion is a liquid crystal material, the average refractive index n2 is 1.56. At this time (n1-n
2) × d becomes 550, and the transmitted light wavelength λ1 (620 in red)
nm, blue and 450 nm).

A voltage was applied to the thus obtained liquid crystal display device of the present embodiment through the TFT in the same manner as above, and various characteristics were measured. As a result, light scattering in the initial state was reduced and contrast High good characteristics were obtained.

In the embodiment, the liquid crystal display element of the present invention is manufactured by using a unique material and a unique manufacturing method. However, similar effects can be obtained as long as the material and the conditions are such that the function of the present invention can be obtained. Needless to say, the same effect can be obtained even if the switching element to be used is another element such as MIM or a display element having a simple matrix electrode structure not using the element. .

[0086]

According to the present invention, it is possible to obtain a liquid crystal display element having a wide viewing angle and a high speed response.

[Brief description of drawings]

1A and 1B are views for explaining an electrode structure constituting a liquid crystal display element of the present invention, in which FIG. 1A is a plan view of a common electrode, and FIG. 1B is a plan view of a pixel electrode.

2A and 2B are views for explaining the structure of the liquid crystal display device of the present invention, where FIG. 2A is a perspective view showing a substrate and electrode configuration, FIG. 2B is a sectional view showing the electrode configuration, and FIG. Cross section showing

3A and 3B are diagrams for explaining the operation of the liquid crystal display element of the present invention, FIG. 3A is a plan view showing an initial state, FIG. 3B is a plan view showing a voltage application state,

FIG. 4 is a cross-sectional view illustrating an alignment of liquid crystal molecules of a liquid crystal display device of a two-layer cell of the present invention,

FIG. 5 is a view for explaining the constitution of the liquid crystal display element of the present invention, (a) is a diagram showing an optical constitution of Voff, Von,
(B) is a plan view showing the electrode configuration and the molecular arrangement, (c) is a cross-sectional view showing the electric field and the molecular arrangement,

6A and 6B are views for explaining the molecular arrangement of the liquid crystal display device of the present invention, where FIG. 6A is a plan view of an upper cell, FIG. 6B is a plan view of a lower cell,

7A and 7B are views for explaining the configuration of the liquid crystal display element of the present invention, FIG. 7A is an exploded perspective view of an initial state, FIG. 7B is an exploded perspective view of a voltage applied state,

8A and 8B are views for explaining the configuration of the liquid crystal display element of the present invention, FIG. 8A is an exploded perspective view of an initial state, FIG. 8B is an exploded perspective view of a voltage applied state,

9A and 9B are diagrams for explaining the operation of another liquid crystal display element of the present invention, in which FIG. 9A is a plan view showing an initial state, FIG. 9B is a plan view showing a voltage application state,

FIG. 10 is a cross-sectional view illustrating another liquid crystal display element of the present invention.

[Explanation of symbols]

 10a, 10b ... Substrate 11, 12 ... Electrode 11a, 12a ... Conductor part 11b, 12b ... Non-conductive part 13, 14 ... Alignment film 15 ... Liquid crystal layer 15a ... Liquid crystal molecule 15b ... Dichroic dye 16 ... Retardation plate 17 ... Switching element 18 ... Polarizing plate (polarizer) 19 ... Color filter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Shohara 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Incorporated in Toshiba Yokohama Works (72) Inventor Ren Hato 8-Shin-Sugita-cho, Isogo-ku, Yokohama, Kanagawa Company Toshiba Yokohama Office

Claims (15)

[Claims] 1. A liquid crystal display device, wherein a liquid crystal layer is sandwiched between opposing first and second substrates each having an electrode to form a plurality of pixels, wherein the electrodes of the substrate have a plurality of narrow widths for each pixel. Of the first substrate and the electrode of the second substrate are formed by juxtaposing the non-conductor part of the conductor part of the electrode of the one substrate and the electrode of the other substrate of the second substrate. The non-conductor parts are arranged to face each other in at least a part,
A liquid crystal display device, wherein the liquid crystal layer is at least two liquid crystal layers, and the liquid crystal layer is a guest-host liquid crystal layer mixed with a dichroic dye or a homogeneously aligned liquid crystal. 2. The liquid crystal display element according to claim 1, wherein a dichroic dye is mixed in at least one layer of the liquid crystal layer. 3. The liquid crystal display element according to claim 1, wherein the molecular arrangements of at least two layers of the liquid crystal layer are arranged orthogonal to each other in the plane direction of the substrate. 4. The liquid crystal display element according to claim 3, wherein a dichroic dye is mixed in two liquid crystal layers arranged orthogonally. 5. The liquid crystal display element according to claim 1, wherein at least three of the liquid crystal layers are liquid crystal layers in which dichroic dyes of yellow, magenta and cyan are mixed. 6. The liquid crystal display device according to claim 5, further comprising a polarizer, which is an analyzer. 7. A liquid crystal display device in which a liquid crystal layer is sandwiched between two opposing substrates each having an electrode to form a plurality of pixels, wherein electrodes are provided for each pixel on both substrates.
When the cross-sectional shape of the substrate is viewed, the arrangement is EL / SS / EL.
When alternately arranged with SS ... And the conductor portion EL of the electrode on one substrate and the non-conductor portion SS of the electrode on the other substrate face each other at least in part and a voltage is applied between the electrodes. The liquid crystal layer has a cell structure in which an oblique electric field is formed, and the liquid crystal layer contains a dichroic dye,
In addition, a liquid crystal display element characterized by disposing one polarizer. 8. A liquid crystal display device, wherein a liquid crystal layer is sandwiched between two opposing substrates each having an electrode to form a plurality of pixels, wherein electrodes are provided for each pixel on both substrates.
When the cross-sectional shape of the substrate is viewed, the arrangement is EL / SS / EL.
When alternately arranged with SS ... And the conductor portion EL of the electrode on one substrate and the non-conductor portion SS of the electrode on the other substrate face each other at least in part and a voltage is applied between the electrodes. A liquid crystal display device having a cell structure in which an oblique electric field is formed in the liquid crystal layer, and a reflective layer being provided on the one substrate. 9. The liquid crystal display device according to claim 8, wherein one polarizer is arranged. 10. A liquid crystal layer containing a dichroic dye,
The liquid crystal display element according to claim 8, wherein one polarizer is arranged. 11. The liquid crystal display element according to claim 1, wherein the liquid crystal layer is vertically aligned in the initial state. 12. The liquid crystal display element according to claim 1, wherein at least one of the substrates is an active matrix substrate having a switching element. 13. The liquid crystal display device according to claim 1, wherein at least one of the substrates has a color filter. 14. When the refractive index of the conductor portion of the electrode is n1, the refractive index of the non-conductor portion is n2, and the thickness of the conductor portion is d, 440 ≦ | (n1-n2) × d 9. The liquid crystal display device according to claim 1, wherein n1, n2 and d are set so that | ≦ 660 (nm). 15. When the wavelength of the transmitted light of each pixel is λ1, the refractive index of the conductor portion is n1, the refractive index of the non-conductor portion is n2, and the thickness of the conductor portion is d. 14. The liquid crystal display according to claim 13, wherein n1, n2 and d are set for each pixel so that 8 × λ1 ≦ | (n1-n2) × d | ≦ 1.2 × λ1. element.