JP3529434B2 - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide an LCD of novel constitution which has a high light scattering characteristic, low driving voltage, bright and high contrast ratio and excellent gradation characteristic, does not invert display in spite of gradation display and is extremely wide in visual field angle. CONSTITUTION:This liquid crystal display element consists of substrates 11, 12 with electrode arranged to face each other and a liquid crystal layer 20 consisting of a nematic liquid crystal compsn. held between these substrates. At least one of the substrates of the substrates 11, 12 with the electrodes arranged to face each other have the regions consisting of conductor parts 13a, 14a having the electrode structure specified in the width of the widest parts to <=50mum by each of one pixel and non-conductor parts 13b, 14b specified in the width of the widest part to <=50mum. The conductor parts 13a, 14a and the non-conductor parts 13b, 14b face each other in at least a part of the regions within the pixels for every one pixel between both substrate 11, 12 disposed opposite to each other; in addition, a relation D>=S/2 is satisfied when the width of the narrowest parts of the non-conductor parts 13b, 14b is defined as S and the spacing between the electrodes of both substrates arranged to face each other as D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel liquid crystal display element and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art In recent years, liquid crystal display elements (hereinafter abbreviated as LCD) have been widely used in word processors, personal computers, projection TVs, small TVs and the like. These LCDs display by controlling the change of light and dark. Such light control methods include a method of combining the polarization effect of liquid crystal molecules with a polarizer, a method of scattering and transmitting light by utilizing the phase transition of the liquid crystal, and a method of adding a dye to the liquid crystal to make the dye visible. There is a method of utilizing the change in the light and shade of the color generated by controlling the light absorption amount.

An LCD using a method combining a polarization effect and a polarizer is, for example, a twisted nematic (TN) type LCD having a molecular arrangement twisted by 90 °, and in principle controls polarization with a thin liquid crystal layer thickness and a low voltage. it can. Therefore, the TN LCD has a fast response speed and low power consumption.
It exhibits high contrast ratio characteristics. This TN LCD is
It is applied to clocks and calculators by simple matrix driving, and is applied to full color display liquid crystal TVs in combination with active matrix driving having a switching element for each pixel and a color filter. However, LCDs that combine these polarization effects and polarizers
Since a polarizing plate is used in principle, the amount of light transmitted through the LCD is significantly reduced. That is, since at least one polarizing plate is used, the amount of transmitted light is at least 50% or less. In addition, the display color and the contrast ratio greatly change depending on the viewing angle and direction depending on the orientation of the liquid crystal molecule arrangement, and thus the viewing angle dependence is provided. In addition to this viewing angle dependence, because of the low transmittance indicated by the ratio of the amount of transmitted light to the amount of incident light,
In reality, the TN LCD does not completely exceed the display performance of a cold cathode ray tube (CRT).

On the other hand, LCDs that utilize the phase transition of liquid crystals and LCDs that control the visible light absorption of dyes, for example, change from a cholesteric phase having a molecular arrangement of a helical structure to a nematic phase having a molecular arrangement of a homeotropic structure. PC-type liquid crystal that causes the phase transition of (1) by applying an electric field, and LCD that uses a white Taylor type GH liquid crystal obtained by adding a dye to the liquid crystal molecules. Since these LCDs do not use a polarizing plate in principle, the transmittance does not decrease. Further, since it has a wide viewing angle, it is applied to automobile equipment, projection type display devices and the like.

However, in such an LCD, sufficient light scattering cannot be obtained unless the liquid crystal layer is relatively thick or the helical strength of the liquid crystal molecules is increased. This is because light scattering is due to various liquid crystal molecular alignments. That is, in order to sufficiently scatter light, for example, in the case of a cholesteric phase having a molecular arrangement of a helical structure, it is necessary to have a helical axis in every direction with respect to the incident light direction. As described above, in order to have helical axes in many directions, the liquid crystal layer thickness must be increased.
Therefore, such an LCD requires a high driving voltage,
There was a problem that the response speed was extremely slow, and it was difficult to apply it to a display element with a large display amount (number of pixels). Also,
As the applied voltage increases, the transmittance changes abruptly, making it difficult to display gray scales. Further, since the molecular alignment of the liquid crystal is significantly different between the light scattering state and the light transmitting state, when the mutual change of the light scattering state and the light transmitting state is performed by electric field control, hysteresis occurs in its electro-optical characteristics. The cause of this hysteresis has not been clarified due to various theories, but when the molecular alignment of the liquid crystal is significantly different, or when the electric field is not applied, the light scattering state (the molecular alignment of the liquid crystal is an assembly of fine domains) It is known that when the liquid crystal molecules are formed, it is likely to occur.
As described above, when the applied electric field-transmittance characteristic has hysteresis, there is a practical problem such that it becomes difficult to perform multiplex driving.

A means for obtaining light scattering by applying a high voltage at a low frequency using Nn liquid crystal in which a conductive substance such as an organic electrolyte is dissolved in another LCD utilizing the phase transition of the liquid crystal (generally called the DS effect). ) And LCDs using means for obtaining light scattering by thermo-optic effect have been proposed. However, even in this case, there is the above-mentioned problem.

Further, as shown in FIG. 36 (a), a large number of capsules are formed in a polymer 3 sandwiched between substrates 1 and 2, and a liquid crystal 4 is enclosed in the capsule-shaped structure,
Further, as shown in FIG. 36B, a polymer dispersion type LCD has been proposed which uses a fibrous polymer structure in which a liquid crystal 6 is dispersed between fibrous polymers 5 to enhance the light scattering property.
However, in such a polymer-dispersed LCD, there are restrictions on the shape of the polymer and the mixing ratio of the polymer and the liquid crystal layer due to the manufacturing method and the principle. Further, since the voltage applied from the outside is divided into the polymer and the liquid crystal, only a part of the applied voltage is applied to the liquid crystal. For this reason, under the present circumstances, it is not possible to obtain sufficient light-scattering properties when attempting to satisfy the drive characteristics that require a sufficiently low drive voltage and a high response speed. Also in these methods, since the molecular alignment of the liquid crystal is significantly different between the light scattering state and the light transmitting state, hysteresis occurs in the electro-optical characteristics as described above. On the other hand, the hysteresis can be reduced by controlling the liquid crystal molecule alignment in the light-scattering state to some extent (for example, mixing a polymer with a hydrophobic substance to control the liquid crystal molecule alignment on the inner surface of the capsule). However, this also weakens the light scattering and is not practical. As described above, the polymer-dispersed LCD has the same problem as other LCDs that utilize the phase transition of liquid crystal.

As a method of scattering light, an alignment treatment is performed for each fine region so that liquid crystal molecules are arranged in various directions on the surfaces of two electrode-attached substrates, and liquid crystal is placed in a gap facing each other with these as inner surfaces. It is also conceivable to have it sandwiched. However, it is practically difficult to make the orientation processing direction (for example, the rubbing direction) different for each fine region, and it is not a means for solving the above-mentioned problem of hysteresis.

[0009]

As described above, the conventional LCD has a low transmittance and a narrow viewing angle dependency.
Alternatively, there is a problem that a high driving voltage is required and a response speed is slow. The present invention has been made to cope with such a problem, and has a high light scattering characteristic, a low driving voltage, a bright, high contrast ratio, and excellent gradation characteristics, and the display is inverted even when gradation display is performed. It is an object of the present invention to provide an LCD having a novel structure with a very wide viewing angle.

[0010]

The LCD of the present invention does not require any medium other than liquid crystal as means for scattering light,
Further, the molecular arrangement of the liquid crystal is not significantly different between the light transmitting state and the light scattering state, and a good light scattering state can be obtained. Further, the LCD can be manufactured without a complicated manufacturing process.

[0011] LCD of the present invention includes a substrate having oppositely disposed electrodes, Ri Do and a liquid crystal layer formed of nematic liquid crystal composition held between the substrates, wherein the oppositely disposed electrodes with board electrodes structure the width of the widest portion in each pixel is the width of the widest part and Ru conductive portion der 50 [mu] m or less as
A region comprising a non-conductive portions Ru der 50 [mu] m or less it
In the liquid crystal display device having the above-mentioned structure, the conductive portion and the non-conductive portion face each other in at least a part of a pixel in each pixel between the oppositely arranged substrates, and Let S be the width of the narrowest part of the conductor,
Assuming that the electrode distance between the two substrates arranged to face each other is D,
The relationship of D ≧ S / 2 is satisfied, and the liquid crystal layer is
Molecules that can have two or more tilt directions when a field is applied
The basic constitution is that the liquid crystal composition has an arrangement.
And has a diameter shorter than the electrode distance D in the gap between the two substrates.
It is characterized by being mixed with fine particles . Or the same
A light-transmitting protective film is formed on the electrode with the same basic structure as above.
The refractive index of the light-protective film is 0.9 to 1 of the refractive index of the electrode material.
It is characterized by being 1 time.

[0012] Also, in between the two substrates facing each other,
An oblique electric field is formed in at least two directions in one pixel with respect to the vertical normal direction between the two substrates, and liquid crystal molecules forming the liquid crystal layer form a splay alignment in a state in which no voltage is applied,
In addition, it is characterized by a molecular arrangement that allows two or more degrees of freedom in tilt-up or tilt-down directions when a voltage is applied.

Specifically, in the present invention, at least one of the electrode-attached substrates which are arranged to face each other has a width of the widest portion of 3
0 μm or less, the nematic liquid crystal composition has a means for inducing a tilt alignment to align in the liquid crystal molecule long axis − direction on the substrate surface, and the liquid crystal molecule alignment direction on the two substrates. Let θ (0 ° ≤ θ ≤ 90 °) be the intersection angle of
Ruth ist angle KOR so as to uniform twist orientations of LC by the pretilt angle on the two substrate surface as a [psi, in a state where no electric field is applied to the liquid crystal layer, wherein [psi is ± theta (where twist When the direction is counterclockwise +, and when it is clockwise-, the liquid crystal twist angle ω is ± θ.
+ 180 ° or ± θ−180 °, and ψ is ± (θ−
180 °), the liquid crystal twist angle ω is ± θ (or more, the same order as the compound sign).

Further, as another embodiment of the present invention, the two substrates which are arranged to face each other are such that, when the cross-sectional shape of the both substrate electrodes in the element normal direction is seen, the upper substrate of the conductor portions of the lower substrate is Board
The width of the portion which does not overlap the conductive portions RE, the width of the portion which does not overlap the conductive portions of the inner lower substrate of the conductor portion of the upper substrate F
E, before the width is conductor portion both substrates EE, the width is the substrates with non-conductive portion and SS, at least every pixel
The substrate having the RE or FE width portion
RE ・ SS ・ FE ・ SS ・ RE ・ SS ・ FE ・ SS when the conductors are electrically connected
- ... and an electrode structure which is a cross-sectional shape across the SS RE and FE are sequentially arranged alternately, the pre-Symbol nematic liquid crystal composition, tilt for arranging the liquid crystal molecular long axis in one direction on the substrate surface It has a means for inducing alignment, and the crossing angle of the alignment direction of liquid crystal molecules on the two substrates is θ (0 ° ≤ θ
≦ a 90 °), Ri der Ruth ist angle KOR so as to uniform twist arranged a liquid crystal composition by the tilt orientation on the two substrate surfaces [psi, in a state where no electric field is applied to the liquid crystal composition , Ψ is ± θ (here, when the twist direction is counterclockwise +, and when the clockwise direction is −), the twist angle ω of the liquid crystal is ± θ + 180 ° or ± θ−180 °, and It is characterized in that when ψ is ± (θ-180 °), the twist angle ω of the liquid crystal is ± θ (above compound sign order). This
Here, the electrode structure is RE, EE, FE, EE, RE, E
RE and FE alternate between E, FE, EE, ... and EE
Electrode structure with cross-sectional shapes arranged in order, or RE
FE ・ RE ・ FE ・ RE ・ FE ・ RE ・ FE ・ ... and RE
Structure having a cross-sectional shape in which FE and FE are alternately arranged in order
It can be made.

As the liquid crystal composition and the liquid crystal molecular alignment according to the present invention, the liquid crystal composition is composed of a liquid crystal having a positive or negative dielectric anisotropy, and can be taken when an electric field is applied.
The tilt direction equal to or more than the direction is a tilt-up direction in the case of the liquid crystal having the positive dielectric anisotropy, and a tilt-down direction in the case of the liquid crystal having the negative dielectric anisotropy. molecular arrangement is a liquid crystal molecule array of the difference between the pretilt angle of the liquid crystal and 0.5 ° or less, the direction to obtain the pretilt angle α0 is a Ru liquid crystal molecular arrangement name from the bend-shaped alignment in the same direction in the vertical It is characterized by

The electrode structure according to the present invention is characterized in that the electrode structure for each pixel is a striped shape consisting of a conductor portion and a non-conductor portion on at least a part of each pixel on both substrates. . Furthermore, it is preferable to have a switching element for each pixel of at least one of the electrode-attached substrates.

[0017] LCD of the present invention, the shorter projection than the electrodes distance D, characterized by comprising on at least one of the two substrates.

In the liquid crystal display device of the present invention, a means for injecting parallel light to the LCD, a means for controlling the incident parallel light by the LCD, and a part of the controlled light traveling direction. And a means for using an optical system for projecting the light, characterized by using the above-mentioned LCD of the present invention as an LCD.

Further, two or more LCDs of the present invention are used, and each of them is irradiated with a parallel light beam which is split and contains at least one of red, blue, and green, or one LC.
It is preferable to display in color by providing D with two or more color filters.

[0020]

The LCD of the present invention controls light with a novel liquid crystal cell structure. Hereinafter, the principle of controlling light in the present invention will be described. The LCD of the present invention realizes a light transmission state by effectively forming a uniform molecular arrangement in each pixel, and has two or more kinds of electric field directions.
A light scattering state is realized by obtaining a refraction lens effect and a diffraction grating effect. Here, the refraction lens effect refers to an effect of refracting incident light by causing liquid crystal molecules to continuously tilt in the thickness direction of the liquid crystal layer and continuously change the refractive index of the liquid crystal layer. Further, the diffraction grating effect means that the extraordinary refractive index n _e and the ordinary refractive index n _o of liquid crystal molecules regularly and alternately appear in the liquid crystal plane to form a diffraction grating in the liquid crystal layer, resulting in parallel light. Refers to the effect of scattering. Light scattering due to such refraction lens effect and diffraction grating effect is
It can be obtained by forming a wall-shaped molecular array at the boundary of the seeds or more in the direction of the electric field.

An example of the molecular arrangement structure in one pixel of the LCD of the present invention is shown in FIG. 1 (b). The molecular arrangement structure shown in FIG. 1B is a splay arrangement and a twisted molecular arrangement, and is characterized in that the liquid crystal molecule pretilt angles on the upper and lower substrate surfaces are substantially equal in the vertical direction. Also, the molecular arrangement structure when a voltage is applied is shown. That is, the electrodes 13 and 14 forming a plurality of stripes are arranged on the upper and lower substrates 11 and 12 in pixel units, and the conductive portions 13a and 14a and the non-conductive portion 13 of each electrode are arranged.
b and 14b are arranged at equal intervals and are offset by 1/2 pitch so as to face each other. The alignment directions of the upper and lower alignment films 15 and 16 are the same, and the liquid crystal molecules M of the liquid crystal layer 20 are in a splay alignment.

When a voltage is applied to the upper and lower electrodes 13 and 14,
A lateral electric field e is generated. In such a molecular arrangement, the tilt directions of the molecules are two directions as shown in the figure depending on how the electric field is applied. This is because the liquid crystal molecule arrangement in the state where no voltage is applied is symmetrical between the upper half and the lower half of the liquid crystal layer. In other words, it is because the tilt direction of liquid crystal molecules has two or more degrees of freedom. Therefore, when a voltage is applied, as shown in the drawing, a wall line (in the present invention, a discriminant in a general sense having a strong memory property that occurs when an electric field is applied, is generated at a boundary portion (DL in the drawing) of a molecule. A "wall" is generated to distinguish it from a nation, and a function of scattering incident light can be obtained. Thus, in order to give the liquid crystal molecules a tilt direction of two or more degrees of freedom, in addition to the molecular arrangement structure of FIG. 1 (b), for example, a nematic liquid crystal composition having a negative dielectric anisotropy as a liquid crystal composition is used. The same effect can be obtained by using, and the liquid crystal molecule array is a completely vertical array in which the pretilt angles of the upper and lower substrates are 90 °. In this case, the degree of freedom in the tilt-down direction of liquid crystal molecules is 2 or more.

In any case, the liquid crystal molecules have an effectively uniform molecular arrangement in the state where no voltage is applied, and the degree of freedom in the tilt-up direction or the tilt-down direction of the liquid crystal molecules is 2 or more. With respect to a certain liquid crystal molecule arrangement, an electrode in which an oblique electric field is applied so as to be applied in two or more directions which are contradictory to each other in a fine region can obtain excellent display performance by solving the above-mentioned problems.

Here, in order to effectively realize the oblique electric field, when the width of the narrowest part of the non-conductor part is S and the electrode interval between both substrates arranged opposite to each other is D, D ≧ S / 2 The requirement is that the relationship of is satisfied. Hereinafter, the reason will be described with reference to FIG. FIG. 2 is a sectional view of an electrode structure used in the present invention. In FIG. 2, the weakest electric field is Es, and this electric field strength determines the strength of the oblique electric field. The magnitude of the oblique electric field intensity controls the alignment of liquid crystal molecules that affect the refractive lens effect and the diffraction grating effect. As a result of the experiment, the electric field strength of Es is 2 of Ev.
It was found to be effectively optically controlled at ^1/2 / 2 or more. Therefore ^{Es ≧ (2 1/2 / 2)} Ev is required conditions, the D ≧ S / 2 to achieve this. By setting D and S in this range, the liquid crystal molecules in the S region can be controlled sufficiently and sufficiently by the electric field, and the tilt direction and the alignment direction can be controlled.

The present invention is intended to enhance the light scattering effect by utilizing the fact that the orientation of liquid crystal molecules changes depending on the presence or absence of an applied voltage having a lateral electric field component when the liquid crystal is not arranged in a uniform twist arrangement. For this reason, a conductor portion and a non-conductor portion are formed in a minute region of the electrode, and the conductor portion of one electrode and the non-conductor portion of the other electrode which face each other across the liquid crystal layer are separated between the substrates. They are face-to-face.

As a premise for explaining the operation of the present invention, a pretilt angle, a uniform twist arrangement, and a non-uniform twist arrangement will be described. The molecules of nematic liquid crystal are in the shape of elongated rods. When the liquid crystal molecules come into contact with the rubbed alignment film on the substrate, the long axis of the rod-shaped molecule is aligned in a certain direction due to the property of the alignment film surface. For example, when the alignment film is a polyimide alignment film or the like, the long axes of the liquid crystal molecules are aligned along the rubbing direction. Further, in the case of a polystyrene alignment film or the like, the long axes of liquid crystal molecules are aligned in a direction perpendicular to the rubbing direction in the film plane direction. Another method of alignment treatment is to deposit an alignment film on a substrate. When silicon oxide is obliquely vapor-deposited on the substrate surface at an incident angle of 85 °, the long axes of the liquid crystal molecules are oriented in the direction of the vapor deposition source.

However, actually, in these alignment treatments, the liquid crystal molecules M are not aligned parallel to the alignment film surface S, but are tilt-aligned with respect to the alignment film surface, that is, the substrate surface S as shown in FIG. As a result, they are raised and oriented at a predetermined angle α ₀ . This angle α ₀ is about 1 to 15 ° for the polyimide alignment film. The angle α ₀ formed by the long axis LA of the liquid crystal molecules in contact with the substrate surface on this substrate surface is called the pretilt angle. At this time, as shown in FIG. 3A, the end portion of the liquid crystal molecule long axis LA raised from the substrate is the leading portion L, and the end portion closer to the substrate side is the trailing portion T.
Then, for explanation of the aligned liquid crystal molecules M, FIG.
As described above, for example, the arrow R from the T direction to the L direction is represented on the plane of the alignment film.

In the example of FIG. 4A, the molecular arrangement of the front substrate or upper substrate 11 is set to F (solid arrow), and the molecular arrangement of the rear substrate or lower substrate 12 is set to R.
This is the case where the alignment treatment is performed so as to be (the arrow of the broken line), and each array is oriented in the opposite direction, that is, the direction different by 180 ° on the substrate plane. In this structure, when a nematic liquid crystal having a positive dielectric anisotropy such that the liquid crystal molecules have no twist (for example, a chiral agent is not mixed) is filled, the liquid crystal molecules M become as shown in FIG. To lower substrate 12
Over the entire length of the liquid crystal layer 20, the liquid crystal layer 20 is arranged at a constant and uniform angle. Generally, such a molecular arrangement is called a uniform arrangement, which is a basic configuration of a conventional LCD. In the LCD having this configuration, when a voltage equal to or higher than the threshold voltage, that is, a drive voltage is applied to the liquid crystal layer, the liquid crystal molecules M are almost aligned with the substrates as shown in FIG. Arrange uniformly in the vertical direction.

FIG. 6 shows the upper substrate 11 from the state of FIG.
FIG. 6 is a view supposing a case where the lower substrate 12 is twisted at an angle θ (≦ 90 °) with reference to FIG. In order to maintain the uniform molecular alignment at this time, the liquid crystal has an angle ψ between both substrates.
It is necessary to take a twisted arrangement only in the counterclockwise direction (the direction of rotation of the arrow in the figure), and to realize this, the liquid crystal material should be selected so that it can be twisted by an angle ψ. The molecular array thus obtained can be called a twisted uniform array,
In this case, this angle ψ is called the twist angle of the uniform arrangement. By the way, in the conventional ST-LCD,
It has a twisted uniform arrangement of 90 ° to 270 °.

FIG. 7 shows the relationship between the transmittance of the LCD and the applied voltage in the ST-LCD having ψ of 180 °. From this figure, the ST-LCD rapidly changes the transmittance at a certain voltage, that is, at the threshold voltage V _th or more.
From this, it is considered that the ST-type LCD has a molecular arrangement similar to that in which no voltage is applied under the applied voltage of the threshold voltage or less, and the twist angle of the liquid crystal is 90 ° or more like this ST-LCD. When defining the molecular arrangement of the LCD of 270 ° or less, it is defined under the applied voltage state below this threshold voltage (when no voltage is applied). Further, in such a transmittance-applied voltage characteristic (curve in FIG. 7), the steepness of the characteristic is generally expressed as a difference between applied voltages of 90% and 10%. It is represented by the value γ divided by the value of. In the LCD of this configuration, when a voltage equal to or higher than the threshold voltage is applied to the liquid crystal layer (when a voltage is applied) in the same manner as in the case of the twist-free uniform arrangement described above, the liquid crystal molecules in the vicinity of the surfaces of both substrates follow the tilt direction. The liquid crystal molecules M are arranged in a direction substantially perpendicular to the substrate as if twisting the arrangement of FIG.

As can be seen from FIG. 6, the twist angle ψ of the uniform arrangement is based on the trailing portion T _F of the liquid crystal molecules of the orientation F of the upper substrate and up to the leading portion L _R of the liquid crystal molecules of the orientation R of the lower substrate. Represents the angle of. ψ
Can be defined as + θ for counterclockwise rotation and −θ for clockwise rotation as shown in FIG.

On the other hand, an arrangement of liquid crystal molecules as shown in FIG. 9B is also possible. Such an arrangement is shown in FIG.
Similar to the arrangement of (1), it can be achieved by maintaining the nematic liquid crystal composition which does not cause twist in the structure of FIG. 9 (a).

In such a molecular arrangement, the molecular arrangements F and R on the upper and lower substrates are in the same direction. As shown in FIG. 9B, in the molecular arrangement, the tilt angle of liquid crystal molecules is the pretilt angle α _{0 of the} upper substrate 11.
After that, the angle gradually decreases, and after the liquid crystal layer thickness d becomes parallel to the substrate 11 at the midpoint d / 2, the pretilt angle α of the lower substrate 12
It is designed to incline in the opposite angle until it reaches ₀ . That is, the leading portions L _F and L _R are arranged close to each other, and the trailing portions T _F and T _R are arranged apart from each other. Such a non-uniform array is called a spray array.

Next, it is considered to obtain a structure in which a twist is added to this splay arrangement as in the uniform arrangement described above. As shown in FIG. 10, the orientation R of the lower substrate 12 is θ with respect to the orientation F of the upper substrate 11 as in the uniform arrangement of FIG.
Considering that the splay alignment on and intersecting only, as shown in FIG. 10, at an angle from the trailing portion T _F of orientation F of the upper substrate 11 and the trailing portion T _R of the orientation R of the lower substrate The liquid crystal molecules must be twisted. Assuming that this twist angle in the splay array is ω, if ω is taken counterclockwise in FIG. 10, ω is positive, so the splay array twist angle ωL is (θ + 180
), And when ω is taken clockwise, ω is negative, so the splay array twist angle ωR is its complementary angle (θ − 180
°). Further, considering the configuration as shown in FIG. 11, when ω is taken clockwise, ω is negative, so the splay array twist angle ωR is (−θ−180 °), and when ω is taken counterclockwise, Since ω is positive, the splay array twist angle ω
L is its complementary angle (-θ + 180 °).

As described above, in the configurations of FIGS. 10 and 11, the splay array twist angle ω is (± θ + 180 °) and (± θ-18).
It can take one of four twist states (0 °). As described above, even in the splay arrangement, corresponding to + θ and −θ of the twist angle ψ in the uniform arrangement,
A twist arrangement can be realized in each case.

Each ω described in FIGS. 10 and 11 is ψ = + θ, −θ, considering the twist angle ψ in the case of uniform twist arrangement, and the angle θ is 0 ≦ θ ≦
In the 90 ° range, in order to realize a twisted splay arrangement when ψ is ± θ, the twist angle ω is (± θ +
180 °), (± θ−180 °), it means that it does not hold. In this case, the range of possible values of ω is ω =
| Θ ± 180 ° | = 90 ° to 270 °, and this twist angle agrees with the practical solution of the conventional ST-LCD. That is, considering that the twist angle is equal to the twist angle of the conventional ST-LCD in the twisted splay arrangement, the twist angle ψ of the uniform arrangement is ± θ and the twist angle ω of the liquid crystal is (± θ + 180 °) or (± θ−180 °)
Becomes This configuration is the first feature of the LCD of the present invention. In such a spray arrangement, the liquid crystal molecules on the surfaces of the upper and lower substrates are tilted (pretilt direction) in opposite directions to each other on the surfaces of the upper and lower substrates. Therefore, in the liquid crystal layer as a whole, there are two tilt directions of liquid crystal molecules when a voltage is applied, because they depend on the tilt direction of the upper or lower substrate surface. Therefore, when the oblique electric field is applied in two directions, the liquid crystal molecules can be easily tilted in two directions, and the light scattering effect which is the effect of the present invention can be easily obtained. is there.

On the contrary, when the uniform arrangement is used, the pretilt directions are effectively the same in the upper and lower substrates, and therefore only one tilt direction can be obtained in the molecular arrangement. Therefore, in order to tilt the liquid crystal molecules in two directions, it is necessary to apply an extremely strong oblique electric field, which is not practical. In the uniform arrangement, according to the results of experiments conducted by the inventors, the electrode configuration of the present embodiment is 60%.
The light scattering effect by the wall cannot be obtained unless a voltage of V or more is applied.

In addition to the above-mentioned splay alignment, there are the following two types in which the liquid crystal molecules have two tilt directions in the liquid crystal molecule alignment. One is a completely vertically aligned liquid crystal molecule arrangement in which the pretilt angles α ₀ of the upper and lower substrates are both 90 °. In this case, a material having a negative dielectric constant anisotropy is used as the liquid crystal composition. When a voltage is applied to the liquid crystal composition exhibiting the negative dielectric anisotropy, the liquid crystal molecules tilt in the direction orthogonal to the electric field direction. Therefore, when an oblique electric field consisting of two directions is applied as in the electrode structure according to the present invention, the liquid crystal molecules are tilted in two directions.
That is, the pretilt angle α ₀ of both the upper and lower substrates is 90 °, which means that the liquid crystal molecules on the surfaces of the upper and lower substrates have no direction in the plane direction of the substrate, and therefore there is no restriction on the tilt direction. In this case, the degree of freedom in the tilt direction of liquid crystal molecules is infinite.

Another case is a case where a liquid crystal composition having a negative dielectric anisotropy is used and the upper and lower substrates have a molecular alignment (generally called a bend alignment) in which the liquid crystal molecules have the same pretilt direction from the vertical direction. . In this case, there are two or more tilt down directions. That is, there are two or more degrees of freedom.

However, even when a liquid crystal composition having a negative dielectric anisotropy is used, when the liquid crystal molecules are slightly tilted from the vertical direction (90 °) and the upper and lower substrates form a uniform tilt arrangement,
The degree of freedom becomes 1, which is outside the scope of the present invention.

The molecular arrangement of the LCD of the present invention is conceptually shown in FIG. The twisting direction and the twisting degree of the liquid crystal molecules can be controlled by the kind and mixing amount of the chiral liquid crystal agent mixed in the liquid crystal. Specific materials include counterclockwise chiral agents and octyl-2-oxy-
4- (4'-n-hexyloxy) -benzol, eg S-811
(Merck Japan), 4-cyano as a clockwise chiral agent
-4 '-(2-methylbutyl) -biphenyl, eg CB-15
(Manufactured by Merck Limited).

12 (a) to 12 (f), the electrode shapes are the same when the alignment directions and pretilt angles α ₀ of the liquid crystal molecules on the surfaces of the upper and lower substrates 11 and 12 are the same and the liquid crystal molecules are not twisted. 12 (a) to 12 (c) show the state when no voltage is applied, and FIGS. 12 (d) to 12 (f) show the influence on the molecular arrangement when they are different.
Indicates the state when voltage is applied. Here, FIG.
12A and 12D show a state in which the upper and lower substrates have the same electrode shape and an electric field is applied only in the liquid crystal layer thickness direction. The liquid crystal molecule has a molecular position d ₀ parallel to the substrate at the midpoint of the liquid crystal layer thickness d, and a voltage is applied from the power supply v ₀ to the electrodes 13 and 14 as shown in FIG. However, its position does not change. FIG. 12B shows the electrode 1 on the lower substrate 12.
4 is formed in the left half in the figure, the right half is an electrodeless area, the other electrode 13 of the upper substrate 11 is formed in the right half in the figure, and the left half is an electrodeless area. , 14 face the electrodeless region.

When the voltage v ₀ is applied, an electric field having a lateral electric field component is applied to the liquid crystal layer due to the mutual displacement of the electrodes, and an electric force line e having an upwardly rising arrow E _R component shown in the drawing is generated. As shown in FIG. 12 (e), the molecule M has a steep and upward molecular arrangement.

On the other hand, FIG. 12C shows the electrode 1 of the lower substrate 12.
4 is formed in the right half of the drawing, the left half is an electrodeless region, the other electrode 13 of the upper substrate 11 is formed in the left half of the drawing, and the right half is an electrodeless region. , 14 face the electrodeless region. When the voltage v ₀ is applied as shown in FIG. 12 (f), an electric field having a lateral electric field component is applied to the liquid crystal layer due to the mutual displacement of the electrodes, and an electric force line having an arrow E _L component rising to the left in the figure is applied. Since e is generated, the orientation of the liquid crystal molecules M is a steep and upward array. That is, the alignment of the liquid crystal molecules when a voltage is applied depends on the formation of the lateral electric field.

Therefore, as shown in FIG. 1A showing the present embodiment, the upper electrode 13 is formed into an electrode pattern in which a plurality of stripe-shaped conductor portions 13a are arranged at equal intervals through non-conductor portions 13b, and The lower electrode 14 has a pattern in which a plurality of stripe-shaped conductor portions 14a are arranged at equal intervals through the non-conductor portion 14b, and when these electrodes are opposed to each other, the conductor portion 13a or 14a of one electrode is formed. Overlap so as to form a gap between the substrates so as to face the non-conductor portion 14b or 13b of the other electrode. In this case, rubbing treatment is performed so that the liquid crystal alignment directions of the upper and lower substrates are the same. As a result, when no voltage is applied, the liquid crystal maintains the splay alignment state in an orderly manner, but when a voltage is applied, the conductor parts are displaced between the upper and lower electrodes, so that an oblique electric field having a transverse electric field component is generated between the electrodes. , The electric force lines e whose inclination directions are alternately changed are formed as shown in the drawing. Since the liquid crystal molecules M are raised and aligned along the lines of electric force, the liquid crystal alignment becomes discontinuous at the boundary between the obliquely upward electric field to the right and the obliquely upward electric field to the left, and a wall line DL is generated.

If a large number of conductive parts and non-conductive parts of electrodes are formed in one pixel, the rising direction of liquid crystal molecules is divided into minute parts, so that many wall lines can be generated in one pixel. It is possible to cause light scattering in this part. The light-scattering region has a width of 5 to 5 around the boundary.
Since the size is 30 μm, light can be scattered over the entire surface of one pixel by dividing the size of the fine regions so as to match within this value range or a value smaller than that. Specifically, set the width of the widest part of the conductor to 50
It is preferable that the width of the widest part of the non-conductive portion is 50 μm or less. Further, in the state where no voltage is applied, since the liquid crystal molecules are continuously arrayed over the entire surface, a light transmitting state can be obtained. Therefore, according to the present invention, it is possible to perform electric field control to obtain a light transmission state when no voltage is applied and a light scattering state when a voltage is applied.

In the present invention, since the tilting direction of the liquid crystal molecules is controlled by the direction of the applied electric field, it is desirable that the upper and lower substrates have the same pretilt angle. It is desirable that the difference be 0.5 ° or less.

Microscopically, the change in the molecular sequence in each region is equal to the change in the molecular sequence, and the response speed takes a value according to this. Therefore, the response speed is TN-LCD or STN of the conventional uniform twist array. -LCDs have been found to be even faster than homogeneously aligned LCDs, and therefore the LCDs of the present invention will also have very fast response speeds.

Further, the LCD of the present invention obtains two states, a light transmitting state and a light scattering state, by a slight change in the alignment of the liquid crystal molecules, so that hysteresis does not occur in the electro-optical characteristics.

Further, since the combination of the molecular alignment states at the boundaries of the above-mentioned regions also differs depending on the twist angle (including 0 °) of the liquid crystal, various combinations are possible,
It is possible to realize various things such as one having steep electro-optical characteristics and one having gentle characteristics. However, if the twist angle is larger than 270 °, the molecular arrangement in the voltage applied state may be memorized when the voltage applied state is switched to the non-applied state. This is not preferable because it results in a hysteresis in the electro-optical characteristics. Therefore, the twist angle of the liquid crystal of the LCD of the present invention is preferably 0 ° to 270 °.

Further, the LCD of the present invention was prepared with a twist angle of 0 °, and each rubbing direction (considering the cell plane, the upper and lower substrates are in the same direction) between two orthogonal polarizing plates and one polarizing plate. When combined so that the absorption axes are parallel, a transmissive display can be obtained even when a scattering light source is used.
In this case, an optical mode utilizing the birefringence effect is obtained, and the above-mentioned transmittance is lowered, but since the light transmission state is realized by the light scattering state of the liquid crystal layer, there is an effect that the viewing angle dependency is small. In particular, since a phenomenon such as display inversion does not occur when gradation display is performed, a display characteristic superior to that of a conventional TN-LCD or the like can be obtained as a direct-view display.

Further, in the LCD of the present invention, since the light scattering state of the liquid crystal layer can be realized by a slight change in the alignment of the liquid crystal molecules, the applied voltage becomes a very small value. Therefore, an advantage that low voltage driving is possible can be obtained.

Next, from FIG. 13 (a) to FIG. 13 (c) and FIG. 14 (a), the electrode structure and the molecular arrangement structure of the LCD of some embodiments of the present invention shown in claims 4 , 5 and 6 will be described. Figure 1
4 (c) and FIGS. 15 (a) to 15 (c). 13 (a), 14 (a) and 15
13A is a perspective view showing an outline of an electrode structure, and FIG.
(B), FIG. 14 (b) and FIG. 15 (b) are sectional views showing the outline of the electrode structure, and FIG. 13 (c), FIG. 14 (c) and FIG. 15 (c) show a state in which an electric field is applied. It is sectional drawing which shows the outline of a liquid crystal molecule arrangement.

FIG. 16 shows that fine particles are mixed or not.
13 shows the structure of the LCD with short protrusions on the substrate .
16 (c), FIG. 14 (c) and FIG. 15 (c) are diagrams showing a cross-sectional structure of the device when applied to the embodiment shown in FIG.

In each figure, upper and lower substrates 11 and 12 made of glass or the like are provided with stripe-shaped upper and lower electrodes 13 and 14 for each pixel on opposing surfaces. Arrow F
Indicates the rubbing direction of the upper substrate 11, the arrow R indicates the rubbing direction of the lower substrate 12, and the dotted line e indicates the power source 21 (FIG. 13A).
Is a line of electric force generated when a voltage is applied to the upper and lower electrodes 13 and 14, and M indicates the alignment of liquid crystal molecules at that time. D
L indicates the generated wall.

In FIGS. 13B and 15B, the width of the upper electrode 13 when viewed from the upper substrate 11 side in the substrate normal direction is FE, and the width of the lower electrode 14 is RE. The width of the gap is SS. Further, in FIG. 14B, the width of a portion where the upper electrode 13 does not overlap the lower electrode 14 when viewed in the substrate normal direction from the upper substrate 11 side is FE, and the width where the lower electrode 14 does not overlap the upper electrode 13 is FE. Is denoted by RE, and the width of the overlapping portion of these electrodes is denoted by EE. Further, members not directly related to the features of the present invention, such as inter-substrate gap agents (spacers), are omitted in any of the drawings.

Further, FIGS. 13A to 15 of the present invention are shown.
Both (c) and FIG. 1 (b) show the shape when the molecular alignment of the liquid crystal is so-called splay alignment. The configuration of FIG. 1 has a structure in which conductive portions and non-conductive portions are opposed to each other between the upper and lower substrates as shown, and the conductive portions and non-conductive portions are alternately arranged on both substrates (such an electrode). The composition is defined as "nesting".)

FIG. 13A to FIG. 15C are shown in FIG.
As can be seen by comparing with (b), the electrode structure of the present invention is
Compared to the “nested” electrode structure shown in FIG.
In the configuration shown in (b), between the upper and lower substrates, between the portions (FE and RE portions) where the conductive portion and the non-conductive portion face each other,
The upper and lower substrates have an electrode structure in which a non-conductive portion (SS portion) is provided. Therefore, as shown in FIG. 13B, the cross-sectional shape of the electrode structure of the upper and lower substrates is thus FE / SS / RE / SS / FE / SS / R.
Since the electrodes are arranged in the order of E, SS, FE, SS, ... For the sake of convenience, such an electrode configuration is defined as “gap with a gap”.

Further, in the structure shown in FIG. 14B, a portion (FE) in which the conductive portion and the non-conductive portion are opposed to each other between the upper and lower substrates.
(RE portion) and the upper and lower substrates have an overlapping portion (EE portion) which is a conductive portion. Therefore, as shown in FIG. 14B, the cross-sectional shape of the electrode structure of the upper and lower substrates is thus FE / EE / R.
Since the electrodes are arranged in the order of E, EE, FE, EE, RE, EE, FE, EE, ..., For convenience, such an electrode configuration is defined as “overlap nesting”.

Further, the one shown in FIG. 15B corresponds to the one shown in FIG.
It is a variation of the electrode structure of (b), and is an electrode structure in the case where the electrode shape in the element plane direction is a so-called stripe shape. That is, the electrode structure shown in FIG. 15B is an electrode structure in which the conductive portion and the non-conductive portion are linearly arranged in parallel. A similar shape is conceivable for the overlapping nest of FIG. 14, but the illustration is omitted here. This kind of "nesting with a gap",
For convenience, the electrode structure in which the electrode structure is “overlap nest” and the electrode shape in the element plane direction is a so-called stripe shape is described as “stripe nest with gap” and “stripe nest nest”. ".

Conversely, as shown in FIG. 14 (a), the LCD proposed in the present invention has the above-mentioned characteristics in the liquid crystal molecule arrangement, and the portion in which the tilt directions of the molecules are remarkably different is added to this. It is shown that in the case of a large number of electrode structures, the planar shape of the electrode structure does not need to stick to an orderly stripe shape as shown in FIG. Nevertheless, one of the features of the present invention is that the "striped nesting with a gap" and the "overlapping stripe nesting" as shown in FIG. 15A is one of the features of the present invention.
This is because it has been found that it has characteristics different from (a).

Now, each of the features of the electrode configuration having these four features and its action will be described. Figure 1
3 (b) and "nest with gap" shown in FIG. 15 (b),
The "stripe insert with a gap" has a non-conductive portion indicated by SS, so that the oblique electric field strength becomes weaker than that of the "insert".
This makes the electro-optical characteristics a gentle curve, while slightly increasing the driving voltage practically. Therefore, driving becomes easy when fine gradation display is performed. In addition, a margin can be provided for the alignment (alignment) between the upper and lower substrates of the electrodes due to the presence of the non-conductive portion indicated by SS, and the productivity is remarkably improved. Also, "overlap nesting" and "overlap stripe nesting" as shown in FIG. 14 (b) are lower than "gap nesting", "gap stripe nesting" and "nesting". An oblique electric field can be obtained with a voltage. Therefore, the driving voltage can be lowered practically. However, since the electric field component applied in the normal direction is generated in the EE portion, the light scattering intensity is slightly lowered. However, as in the case of the "gap insert with gap" and the "stripe insert with gap", since the conductive portion indicated by EE is provided, a margin can be provided for the alignment (alignment) between the upper and lower substrates of the electrode, and the productivity is remarkably improved. To do.

Further, as compared with "nesting with gap" and "overlapping nest", "stripe nesting with gap" and "overlapping stripe nesting" are walls (FIG. 13 (c), FIG. 14).
The appearance shape of (c) and the alignment discontinuity indicated by DL in FIG. 15C becomes a jagged shape as shown in FIG. This shape enhances the light scattering intensity as compared with the linear shape. We have confirmed by various experiments that such a jagged shape becomes more jagged as the electrode pattern has a more ordered stripe shape. From this,
It can be said that these "striped nesting with a gap" and "overlapping striped nesting" electrode structures have the feature of obtaining strong light scattering intensity as a result.

As described above, these various electrode configurations have respective characteristics and are means for solving the above-mentioned conventional problems. In the description so far, the molecular alignment of the liquid crystal has been described as a splay-like molecular alignment without twisting, but as described above, if the tilt direction of the liquid crystal molecules is a molecular alignment with two or more degrees of freedom, It goes without saying that the same effect can be obtained.

Now, these various electrode configurations of the present invention,
When the above-mentioned wall is generated in the molecular arrangement, the oblique electric fields are configured to be reciprocal in each fine region. Therefore, even if the voltage is continuously applied, the liquid crystal molecules are in the state in which the wall is generated. It is difficult to maintain the molecular arrangement. This is because it is difficult to change the arrangement shape of the liquid crystal molecule array so finely. In other words, the force for maintaining such a difficult molecular arrangement form is insufficient only by the external force such as the electric field and the magnetic field. In order to solve such a problem, fine particles having a length in the liquid crystal layer thickness direction shorter than the liquid crystal layer thickness d are mixed into the gap between both substrates. Alternatively, the height of the liquid crystal layer in the thickness direction is the electrode spacing D (this spacing is substantially the liquid crystal layer thickness d.
We have found that providing a lower protrusion (equal to) on at least one of the two substrates solves the problem.

FIG. 16 shows the outline of this configuration. As shown in the figure, it has a structure in which fine particles 22 smaller than the liquid crystal layer thickness d are added. Thus, when the liquid crystal layer 20 is provided with fine particles or protrusions, if the fine particles or protrusions are present at the locations where the walls appear, the presence of these fine particles causes the finely-arranged shape to be changed, that is, the molecular alignment state, that is, Found that they maintained the molecular arrangement in which many walls appeared. Since such fine particles and projections have a function of maintaining a large number of walls, they are called "wall supports". As means for obtaining such a function, in addition to the method shown in the present invention, fine particles having a size equal to the thickness of the liquid crystal layer are mixed into the liquid crystal layer more than necessary (that is, a substrate gap agent is mixed).
It can also be obtained. However, in this case, in order to maintain a large number of walls, it is necessary to mix a large number of substrate gap agents, which adversely affects the light transmission state. Specifically, it is the influence of light scattering by the substrate interstitial agent and light scattering by the liquid crystal molecule alignment on the surface of the substrate interstitial agent. In the present invention, in order to reduce these influences, it has been decided to use, as the wall support, fine particles or protrusions having a thickness smaller than the liquid crystal layer thickness d. The inventors have confirmed through experiments that the light scattering caused by the fine particles and the projections smaller than the liquid crystal layer thickness d can be brought to a problem-free level.

In order to obtain the function of this wall support, in addition to the above-mentioned fine particles and protrusions, TFT, MI
It has been confirmed that the steps (steps caused by the thickness of the wiring electrodes and the semiconductor layer) inevitably provided on the M substrate have the same function in the vicinity of the steps.

Further, as shown in FIG. 18, FIG. 19 and FIG. 20, the upper transparent insulating film 17 is formed on the upper electrode 13 or the upper electrode 13 and the protrusion, and the lower electrode is formed on the lower electrode or the lower electrode and the protrusion. By forming the translucent insulating film 18, it is possible to improve the transmittance and the contrast when no voltage is applied. The alignment film 1 is formed on these translucent insulating films.
5, 16 are formed. However, in FIG. 20, the lower translucent insulating film is not provided. The electrodes 13 and 14 are made of ITO and have a refractive index of about 1.9, which is about the same as that of the substrate, alignment film and liquid crystal layer.
Higher than 1.5. Therefore, the refractive index of the transparent insulating film is selected to be equal to or close to the refractive index of the electrode material. Practically, it is preferably 0.9 to 1.1 times the refractive index of the electrode material. The reason will be described below. As shown in FIG. 21, ITO and other materials, that is, the substrates 11 and 12,
The difference in the refractive index of the liquid crystal layer 20 is large. On the other hand, the pixel electrode is I
TO conductor portions 13a and 14a and non-conductor portions 13b and 14
Since it is divided into fine regions of b, the optical paths overlap due to the difference in refractive index between the conductor portion and the non-conductor portion in the pixel electrode, resulting in light interference. Therefore, if such light interference can be eliminated, it is possible to improve the transmittance and the contrast when no voltage is applied.

Light interference has a large difference in refractive index between the pixel electrode material and other materials, and since the conductive portion and the non-conductive portion are divided into fine regions within the pixel electrode, incident light is It occurs because the degree of refraction is different between the conductor and non-conductor parts. Therefore, in order to prevent light interference between the pixel electrodes, incident light may be refracted in the same manner between the conductor portion and the non-conductor portion in the pixel electrode. Therefore, if a translucent insulating film having a refractive index substantially the same as that of the pixel electrode material is applied on the pixel electrode, the light incident on the non-conductor portion in the pixel electrode is also changed to the light incident on the conductor portion. Since light is refracted equally, it is possible to suppress light interference. The pixel electrode is made of a translucent conductor, practically ITO. For this reason,
A translucent insulating film having a refractive index almost the same as that of ITO may be used. That is, within the range of 0.9 to 1.1 times the refractive index of the electrode material, there is almost no decrease in transmittance due to optical interference. If the thickness of the translucent insulating film is 1/2 or more of the thickness of the translucent electrode layer such as ITO, a sufficient effect can be obtained.

[0070]

Embodiments of the LCD of the present invention will be specifically described below with reference to the drawings. Example 1 FIG. 1A is a perspective view showing a pattern of upper and lower electrodes of this example, and FIG. 1B is a schematic sectional view of a liquid crystal cell in which electrodes are opposed to each other. A transparent common electrode 13 made of ITO is formed on the entire surface of one surface of an upper substrate 11 made of glass, and an upper alignment film of polyimide (AL-3046, made by Japan Synthetic Rubber) on the surface 1
5 is laminated. A pixel electrode 14 made of ITO is formed on one surface of the lower electrode 12 made of the other glass, and a lower alignment film of polyimide (AL-3046, made by Japan Synthetic Rubber) 16 is formed on the surface thereof.
Are stacked. Pixel electrodes 14 each having a size of 300 μm × 300 μm are arranged in a mosaic pattern on a pixel-by-pixel basis. The pretilt angle of the upper and lower alignment films 15 and 16 is 3 °.

The upper electrode 13 is a pattern in which a plurality of slits each having a width of 20 μm, that is, a non-conductive portion 13b, and conductive portions 13a having a width of 20 μm are arranged in a stripe pattern at a pitch of 40 μm, and each pixel has a width of 300 μm. 6 conductive parts in 1
3a is formed. The lower electrodes 14 facing each other also have a pattern in which a conductive portion 14a having a width of 20 μm and a non-conductive portion 14b having a width of 20 μm are arranged at equal intervals, and six conductive portions 14a are formed within a width of 300 μm.

The conductive parts of these electrodes are offset from each other by 20 μm with the upper and lower substrates facing each other, and the conductive part 13a or 14a of one electrode faces the non-conductive part 14b or 13b of the other electrode. The lower electrode 14 has a TFT switching element 19 and is connected to the gate line 23 and the signal line 24.

The alignment directions F and R of the upper and lower alignment films 15 and 16 are set so as to be orthogonal to the conductive parts of the electrodes as shown and to be in the same direction. In addition, the gap between the upper and lower substrates is 10μ
m to form a liquid crystal cell. A nematic liquid crystal (ZLI-3926, manufactured by Merck Japan) having a positive dielectric anisotropy is filled in the gap between the substrates to form a liquid crystal layer 20. This liquid crystal has a large birefringence (Δn) of 0.2030. By increasing the birefringence (Δn) and selecting a liquid crystal layer having a large thickness of 10 μm, the light scattering property of the LCD can be enhanced.

A voltage was applied from the power source 21 to the LCD of the present invention thus obtained through the TFT 19 to measure the electro-optical characteristics (transmittance-applied voltage curve). When a voltage is applied, an electric field having a lateral electric field component is generated between the electrodes, and the direction of the lateral electric field component changes in a minute range of one pixel. Therefore, the liquid crystal molecules M of the liquid crystal layer 20 change their arrangement according to the electric field. .
Therefore, a large number of wall lines DL are arranged at the boundary of the liquid crystal alignment.
Occurs and creates a light scattering state.

To obtain the transmittance-applied voltage curve, L
A He-Ne laser beam was incident on the CD and the transmittance was measured. The measurement result is shown in FIG. The spot diameter of light is 2m
At m 2, the transmitted laser light was detected by a photodiode at a distance of 20 cm from the LCD. The applied voltage was gradually increased from 0V to 5V, and then gradually decreased from 5V to 0V. When no voltage was applied (0 V was applied), the transmittance was about 80%, showing a bright transmittance characteristic. At an applied voltage of 2.8 V, the minimum transmittance is 0.4%.
Then, a good light scattering state was obtained. Further, as is clear from FIG. 23, there was no hysteresis in the electro-optical characteristics. Further, when the response speed was measured at applied voltages of 2.8 V and 0 V, a very fast value of 7 msec for rising and 25 msec for falling was obtained.

Example 2 This example is shown in FIGS. 22 (a) and 22 (b). As shown in FIG. 22A, the patterns of the conductive portion 13c and the non-conductive portion 13d of the upper electrode 13 and the conductive portion 14a and the non-conductive portion 14b of the lower electrode 14 are orthogonal to each other in one pixel. The structure is the same as that of the first embodiment except for the pattern of the conductive portion. Here, the parts having the same numbers as in Example 1 represent the same parts. However, the liquid crystal layer has a positive dielectric constant anisotropy (ZLI-39
26, manufactured by Merck Japan Ltd., a left-handed chiral agent (S-81
1, a product of Merck Japan) was used. In addition, as shown in FIG. 22B, the alignment directions F and R of the upper and lower substrates were shifted by 180 °, and the liquid crystal molecules were arranged in a splay arrangement in which they were twisted by 180 °.

In this structure, the upper and lower electrodes 13, 14
Area where the conductive portions 13c and 14a overlap with each other, and the conductive portion 13c or 14a of one electrode is a non-conductive portion 14b of the other electrode.
Alternatively, a region facing 13d is generated. However, a lateral electric field component generated when a voltage is applied is complicatedly generated and acts to disturb the alignment of liquid crystal molecules. Therefore, sufficient light scattering can be obtained in a very small area of one pixel with a very fast response.

Example 3 FIG. 24 (a) is a schematic sectional view of a liquid crystal cell in which electrodes are opposed to each other in this example, FIG. 24 (b) shows an upper electrode pattern of one pixel region, and FIG. Shows the lower electrode pattern of one pixel area. As shown in FIGS. 24A and 24B, as the upper substrate 11, a glass substrate in which a common electrode 13 of ITO including a non-conductive portion 13b having a bent stripe pattern and a conductive portion 13a is formed in each pixel is used. A black matrix made of chrome is formed over the entire non-pixel portion. As shown in FIGS. 24 (a) and 24 (c), a common electrode 1 of ITO, which is composed of a non-conductive portion 14b and a conductive portion 14a having a bent stripe pattern in each pixel as the lower substrate 12, is formed.
4 and a glass substrate on which a switching element composed of TFT is formed is used. The upper electrode pattern shown in FIG. 24B has the width of the conductive portion in the direction orthogonal to the stripe extension direction.
The width between the peaks of the conductive portion was 10 μm, and the width of the non-conductive portion was 10 μm. In the lower electrode pattern shown in FIG. 24 (c), the width of the conductive portion was 5 μm and the width of the non-conductive portion was 10 μm.

On the electrode pattern of this substrate, an alignment film 15,
16 (trade name SE-7120, manufactured by Nissan Chemical Industries, Ltd.) (measurement value of pretilt angle 6 °) is formed, and its surface is subjected to rubbing treatment in directions F and R shown in the figure. Next, dry particles were sprayed on the lower substrate side as a substrate gap agent so that the liquid crystal layer thickness was 7.5 μm (trade name Micropearl SP, manufactured by Sekisui Fine Chemical Co., Ltd.) (particle size 7.5 μm) to a dispersion density of 100 particles / mm ^2. Liquid crystal composition with positive dielectric anisotropy between these substrates after spraying by the method (trade name ZLI-3926, manufactured by Merck Japan)
By sandwiching (Δn = 0.3030), an LCD of this example having the above-mentioned “nested insert” electrode configuration was obtained. Here, the reason why the liquid crystal layer thickness is increased and the dielectric anisotropy of the liquid crystal composition is increased is to enhance the light scattering property in the light scattering state.

A voltage was applied to the LCD thus obtained through a TFT, and the electro-optical characteristics (transmittance-applied voltage curve) were measured by the method shown in Example 1. The measurement result is shown in FIG. When no voltage was applied (0 V was applied), the transmittance was about 80%, showing a bright transmittance characteristic. Also,
When the applied voltage was 3.1 V to 3.9 V, the minimum transmittance was 0.4%, and a good light scattering state was obtained. Further, as is clear from the figure, there was no hysteresis in the electro-optical characteristics. Further, when the response speed was measured at an applied voltage of 3.1 V and 0 V, a very fast value of 6 msec for rising and 18 msec for falling was obtained.

Next, a voltage was applied through the TFT of the lower substrate, and the maintenance state of the above-mentioned wall was examined by observing the molecular arrangement by a polarization microscope and measuring the light scattering state by the transmittance measurement. In this example, when the applied voltage of 3.1 V was continuously applied, it was confirmed that the initial wall arrangement was maintained even after 1 hour.

Example 4 Using the same substrates 11 and 12 as in Example 3, alignment films 15 and 1 were used.
6 is a treatment agent for vertical alignment treatment (trade name ODS-E (Octadecylt
rietoxysilane alcohol solution), made by Chisso),
The substrate was vertically aligned. Here, the vertical alignment treatment is performed by immersing each substrate in the above alcohol solution.
The obtained pretilt angle was 90 ° for both the upper and lower substrates. This example was carried out under the same conditions and materials as in Example 3, except that a nematic liquid crystal material having a negative dielectric anisotropy (ZLI-4850 (Δn = 0.208), manufactured by Merck Japan) was used as the liquid crystal composition. An example LCD was obtained. When various characteristics were measured in the same manner as in Example 3, excellent results substantially equivalent to those in Example 3 were obtained as shown in FIG. Example 5 FIG. 25A shows an upper substrate electrode pattern, and FIG. 25B shows a lower electrode pattern diagram. A black matrix made of chromium was formed on the entire non-pixel portion as an upper substrate, and a common electrode 13 in which a conductive portion 13a of a wavy stripe and a non-conductive portion 13b narrower than this were formed for each pixel was deposited by ITO patterning. A glass substrate is used. As the lower substrate, a glass substrate with a switching element including a lower electrode 14 having a conductive portion 14a having a non-conductive portion 14b narrower than the non-conductive portion 13b of the upper substrate and a TFT (not shown) was used. An area 14c surrounding the lower substrate is a wiring and TFT forming area. Using these substrates, the LCD of the present invention having the above-mentioned "double nesting" electrode configuration was prepared using the same conditions and materials as in Example 3. The electro-optical characteristics (transmittance-applied voltage curve) of the LCD in this example were measured under the same method and conditions as in Example 3. The result is shown in FIG.

When no voltage was applied (0 V was applied), the transmittance was about 80%, which was a bright transmittance characteristic. Also,
A favorable light scattering state was obtained with a minimum transmittance of 0.5% at an applied voltage of 2.5 V to 3.3 V and a lower voltage than Example 3. Further, as is clear from the figure, there was no hysteresis in the electro-optical characteristics. When the response speed was measured at an applied voltage of 2.5 V and 0 V, a very fast value of 5 msec for rising and 12 msec for falling was obtained.

Next, a voltage was applied to the LCD of this example through the TFT, and the maintenance state of the above-mentioned wall was examined by observing the molecular arrangement by a polarization microscope and measuring the light scattering state by measuring the transmittance. In this example, when the applied voltage of 2.5 V was continuously applied, it was confirmed that the initial wall arrangement was maintained even after 1 hour.

Example 6 FIG. 26A shows an upper substrate electrode pattern, and FIG. 26B shows a lower electrode pattern diagram. A black matrix made of chrome is formed on the entire non-pixel portion as an upper substrate, and a linear stripe conductive portion 13a and a non-conductive portion 13 are formed for each pixel.
A glass substrate is used in which the common electrode 13 formed with b is formed by patterning ITO. As the lower substrate, a lower electrode 14 including a linear stripe conductive portion 14a and a non-conductive portion 14b, and a glass substrate with a switching element including a TFT are used for each pixel. The width of the conductive part of the upper and lower electrodes is 5 μm, and the width of the non-conductive part is 10 μm.

Using these substrates, using the same conditions and materials as in Example 3, the above-mentioned "stripe nesting member with a gap" was used.
An LCD of this example having the above electrode configuration was produced. The electro-optical characteristics (transmittance-applied voltage curve) of the LCD in this example were measured under the same method and conditions as in Example 3. The result is shown in FIG.

When no voltage was applied (0 V applied), the transmittance was about 80%, which was a bright transmittance characteristic. Also,
A minimum transmittance of 0.2% was obtained at an applied voltage of 3.2 V to 3.9 V, and a good light scattering state of Example 3 or higher was obtained. Further, as is clear from the figure, there was no hysteresis in the electro-optical characteristics. Also, when the response speed was measured at an applied voltage of 3.2 V and 0 V, the rising edge was 6 msec and the falling edge was 18 msec.
And got an extremely fast value. Next, a voltage was applied to the LCD of this example through the TFT, and the maintenance state of the above-mentioned wall was examined by observing the molecular arrangement by a polarization microscope and measuring the light scattering state by the transmittance measurement. In this example, when the applied voltage of 3.2 V was continuously applied, it was confirmed that the initial wall arrangement was maintained even after 1 hour. Example 7 After using the same upper and lower substrates as in Example 3 and carrying out an alignment treatment by the same method and material, fine particles (trade name: Micropearl, manufactured by Sekisui Fine Chemical Co., Ltd.) (grains) as the wall support described above on the upper substrate side. 5.0 μm diameter) was dispersed by a dry spraying method so that the dispersion density was 1000 pieces / mm ^2, and the subsequent steps were carried out in the same manner as in Example 1.
The LCD of the present invention was manufactured by the same method and material. When various characteristics were measured under the same method and conditions as in Example 3, FIG.
As shown in FIG. 7, excellent results almost equal to those in Example 3 were obtained.

Further, as in Example 3, a voltage was applied to the LCD through the TFT, and the maintenance state of the above-mentioned wall was examined by observing the molecular arrangement by a polarization microscope and measuring the light scattering state by the transmittance measurement. In this example, when the applied voltage of 3.1 V was continuously applied, it was confirmed that the initial wall arrangement was maintained even after 10 hours.

Example 8 FIG. 28 (a) is a schematic sectional view of a liquid crystal cell in which electrodes are opposed to each other, FIG. 28 (b) shows an upper electrode pattern of one pixel region, and FIG. 28 (c) shows one pixel region. The lower electrode pattern is shown. The electrode patterns on the upper and lower substrates are the same as in Example 3. The transparent insulating films 17 and 18 are formed on the pixel electrodes 13 and 14 on both the upper and lower substrates.
As a translucent insulating material with a refractive index of 1.9 (trade name RTZ-206,
(Catalyst Chemical Co., Ltd.) was overcoated to form a transparent layer having a thickness of 1.0 μm to obtain a substrate having a structure shown in FIG.
LCD using this substrate under the same method and conditions as in Example 3
Got The electro-optical characteristics (transmittance-applied voltage curve) of the obtained LCD were measured by the method shown in Example 1. The measurement result is shown in FIG.

When no voltage was applied (0 V was applied), the transmittance was about 85%, which was a bright transmittance characteristic. Also,
When the applied voltage was 3.3V, the minimum transmittance was 0.4%, and a good light scattering state was obtained. Further, as is clear from the figure, there was no hysteresis in the electro-optical characteristics. Also, the applied voltage
When the response speed was measured at 3.1 V and 0 V, a very fast value of 6 msec for rising and 18 msec for falling was obtained. Next, a voltage is applied through the TFT on the lower substrate,
The maintenance state of the above-mentioned wall was examined by observing the molecular arrangement by a polarization microscope and measuring the light scattering state by measuring the transmittance. In this example, when the applied voltage of 3.1 V was continuously applied, it was confirmed that the initial wall arrangement was maintained even after 1 hour.

Example 9 Using the upper and lower substrates having the electrode patterns shown in Example 4,
The pixel electrode is overcoated with a translucent insulating material (trade name RTZ-606, made by Catalysts & Chemicals Industry) with a refractive index of 1.90.
A substrate having a transparent layer having a thickness of 1.0 μm was obtained. An LCD was obtained using this substrate under the same method and conditions as in Example 4.
The electro-optical characteristics (transmittance-applied voltage curve) of the obtained LCD were measured by the method shown in Example 1. Figure 2 shows the measurement results
9 shows.

As shown in FIG. 29, excellent results almost equivalent to those of Example 8 were obtained. Further, the response speed and the maintained state of the wall were almost as good as those in Example 8. Further, even with respect to incident light, no optical interference was caused by the electrodes when no voltage was applied, the transmittance was improved when no voltage was applied, and the effect of improving contrast was observed.

Example 10 Using the upper and lower substrates having the electrode patterns shown in Example 5,
The pixel electrode is overcoated with a translucent insulating material (trade name RTZ-606, made by Catalysts & Chemicals Industry) with a refractive index of 1.90.
A substrate having a transparent layer having a thickness of 1.0 μm was obtained. An LCD was obtained using this substrate under the same method and conditions as in Example 5.
The electro-optical characteristics (transmittance-applied voltage curve) of the obtained LCD were measured by the method shown in Example 1. Figure 2 shows the measurement results
9 shows.

As shown in FIG. 29, excellent results almost equivalent to those of Example 8 were obtained. Further, the response speed and the maintained state of the wall were almost as good as those in Example 8. Further, even with respect to incident light, no optical interference was caused by the electrodes when no voltage was applied, the transmittance was improved when no voltage was applied, and the effect of improving contrast was observed.

Example 11 An LCD was obtained by the same method and conditions as in Example 8 except that the upper and lower substrates having the electrode patterns shown in Example 6 were used. Electro-optical characteristics of the obtained LCD (transmittance-applied voltage curve)
Was measured by the method shown in Example 1. The measurement result is shown in FIG.

As shown in FIG. 29, excellent results almost equivalent to those of Example 8 were obtained. Further, the response speed and the maintained state of the wall were almost as good as those in Example 8. Further, even with respect to incident light, no optical interference was caused by the electrodes when no voltage was applied, the transmittance was improved when no voltage was applied, and the effect of improving contrast was observed.

Example 12 An LCD was obtained by the same method and conditions as in Example 8 except that the upper and lower substrates having the electrode patterns shown in Example 7 were used. Electro-optical characteristics of the obtained LCD (transmittance-applied voltage curve)
Was measured by the method shown in Example 1. The measurement result is shown in FIG. As shown in FIG. 29, excellent results almost equivalent to those in Example 8 were obtained. Further, the response speed and the maintained state of the wall were almost as good as those in Example 8. Further, even with respect to incident light, no optical interference was caused by the electrodes when no voltage was applied, the transmittance was improved when no voltage was applied, and the effect of improving contrast was observed.

Example 13 As shown in FIG. 30, using a substrate in which an upper electrode 13 was formed on an upper substrate 11 and a lower electrode 14 was formed on a lower substrate 12 by the electrode pattern shown in Example 6, both substrates were formed. Particle size on the electrode side surface
Fine particles 22 of 1.5 μm (trade name: Micropearl SP, manufactured by Sekisui Fine Chemical Co., Ltd.) were sprayed at a dispersion density of 1000 particles / mm ² . A transparent insulating film (trade name RTZ-206, made by Catalysts & Chemicals Industry) 17, 1 on top of these electrodes and particles
8 was overcoated to finish the surfaces of both substrates into uneven surfaces. An LCD was obtained by the same method and conditions as in Example 8 except that the upper and lower substrates were used. The LCD obtained is from Example 8.
Excellent electro-optical characteristics, response speed, and wall maintenance were obtained. In addition, the translucent insulating film optically eliminated the break in the conductor portion of the electrode and prevented optical interference.

Example 14 FIG. 31 (a) is a schematic sectional view of a liquid crystal cell in which the electrodes of this example are opposed to each other, FIG. 31 (b) shows the upper electrode pattern of one pixel region, and FIG. 31 (c) shows FIG. 31D shows the lower electrode pattern of one pixel area and shows the alignment of liquid crystal molecules when a voltage is applied. As the upper electrode 13, an ITO solid electrode was used as shown in FIG. No black matrix for shielding the non-pixel portion is provided. The size of one pixel of the lower electrode 14 is 30 μm × 40 μm as shown in FIG.
A spray pattern in which O is 4.5 μm wide and the non-conductor portion is 7 μm wide is formed for each pixel. The TFT switching element 19 is formed for each pixel to obtain a lower substrate having 1280 × 1024 pixels.

Alignment film 15, on the electrode pattern of this substrate,
16 (trade name SE-7120, manufactured by Nissan Chemical Industries, Ltd.) (measurement value of pretilt angle 6 °) is formed, and its surface is subjected to rubbing treatment in directions F and R shown in the figure. Next, dry particles were sprayed on the lower substrate side as a substrate spacing agent to a liquid crystal layer thickness of 6.0 μm (trade name Micropearl SP, manufactured by Sekisui Fine Chemical Co., Ltd.) (particle size 6.0 μm) to a dispersion density of 100 particles / mm ^2. Liquid crystal composition with positive dielectric anisotropy between these substrates after spraying by the method (trade name: ZLI-4792, manufactured by Merck Japan)
The LCD of this example was obtained by sandwiching (Δn = 0.094).

The features of the cell structure of this embodiment are shown by the following three features. First, the liquid crystal molecule array is aligned parallel to the electrode stripe direction in the state where no voltage is applied. That is, the liquid crystal molecule alignment is orthogonal to the oblique electric field direction when a voltage is applied. Therefore,
When a voltage is applied, an oblique electric field is formed in a direction orthogonal to the liquid crystal molecule array, and the liquid crystal molecules tilt while twisting in this direction. As a result, the liquid crystal molecule alignment in the state in which the voltage is applied is as shown in FIG. 31 (a) when seen from the cross section and as shown in FIG. 31D when seen in the plane. Due to such an arrangement of liquid crystal molecules, the refractive index with respect to the polarization component in the electrode stripe direction and the direction orthogonal thereto is such that the extraordinary refractive index n _e and the ordinary light refractive index n _o of the liquid crystal molecules are regularly alternated in the direction orthogonal to the electrode stripe direction. To array. Therefore, a diffraction grating is formed in the liquid crystal layer and parallel light can be scattered.

Secondly, in order to effectively obtain the oblique electric field, the electrode distance D between the two substrates arranged to face each other is set to satisfy the relationship of D ≧ S / 2. Here, S is the width of the narrowest part of the non-conductor part in the electrode part. In this embodiment, the width S between the stripe electrode patterns (FIG. 31 (c)) is 7 μm, and the electrode spacing D between the two substrates arranged to face each other is 6 μm. Therefore, the above relational expression is satisfied. There is.

Thirdly, the Δnd of the liquid crystal layer is set to 564 nm. This value is smaller than in the above-mentioned embodiment. This is because the light scattering effect of the diffraction grating depends on Δnd. The light scattering effect of the diffraction grating is GALE, M. et al .: 19
According to 79, J.appl.Photogr.Engng, 4,41, it is shown by the following formula. T = cos ² (πΔnd / λ) where T is the intensity of scattered light (intensity with respect to the incident light), and λ is the wavelength of the incident light. From this equation, the light scattering effect of the diffraction grating depends on Δnd. In the configuration of the liquid crystal cell of this embodiment, this Δnd changes depending on the applied voltage. The range of change is from 0 to the value after the set liquid crystal layer Δnd (564 nm). From the above equation, the light scattering effect of the diffraction grating has an extreme value with respect to Δnd. Therefore, if the set value of Δnd is significantly larger than the extreme value of the above equation, the extreme value occurs in the electro-optical characteristics of the liquid crystal cell. This makes gradation expression using an analog signal difficult. Therefore, in this embodiment, Δnd of the liquid crystal layer is set to 564 nm in consideration of this. As described above, this embodiment is similar to the other embodiments in that the refractive lens effect formed by the liquid crystal molecule arrangement (the above-mentioned wall arrangement: the liquid crystal molecules continuously change their inclination in the thickness direction of the liquid crystal layer and the refractive index changes continuously). In addition to the effect of refracting incident light by changing it, the structure is such that a diffraction grating effect can be clearly obtained.

A voltage was applied to the LCD thus obtained through a TFT, and the electro-optical characteristics (transmittance-applied voltage curve) were measured by the method shown in Example 1. The measurement result is shown in FIG. When no voltage was applied (0 V was applied), the transmittance was about 80%, showing a bright transmittance characteristic. Also,
When the applied voltage was 3.2 V or more, the minimum transmittance was 0.2%, and a good light scattering state was obtained. Further, as is clear from the figure, there was no hysteresis in the electro-optical characteristics. Further, when the response speed was measured at an applied voltage of 3.2 V and 0 V, a very fast value of 7 msec for rising and 23 msec for falling was obtained.

Example 15 As alignment films, alignment films 15 and 16 exhibiting vertical alignment (trade name JALS-204-R14, manufactured by Japan Synthetic Rubber Co., Ltd.), and liquid crystal composition having negative dielectric anisotropy Liquid crystal composition (Product name ZL
LCD was obtained in the same manner as in Example 14 except that I-4318 (manufactured by Merck Japan) (Δn = 0.1243) was used.

FIG. 33 shows the alignment of the liquid crystal molecules in the plan view of the LCD of this example when no voltage is applied and when a voltage is applied.
(A), It shows in FIG.33 (b). No voltage applied (Fig. 33)
In (a)), the liquid crystal molecules are uniformly arranged (vertically aligned). On the other hand, in the voltage applied state (FIG. 33 (b)), the ITO tilts down to the rubbing direction where the upper and lower substrates are opposed to each other, and conversely, the oblique electric field is generated in the electrode stripe direction in the region of the TFT substrate where there is no ITO. Since it occurs in a direction orthogonal to, tilt down in that direction. Therefore, as shown in the figure, the LCD of the present embodiment is similar to the LCD of the fourteenth embodiment in that the refractive index with respect to the polarization components in the electrode stripe direction and the orthogonal direction thereof is the extraordinary refractive index n _{e of the} liquid crystal molecules when a voltage is applied. The ordinary light refractive index n ₀ is regularly and alternately arranged in the direction orthogonal to the electrode stripe direction. As a result, a diffraction grating is formed in the liquid crystal layer, and parallel light can be scattered.

The present embodiment has a structure for obtaining the diffraction grating effect and the refraction lens effect as in the case of the fourteenth embodiment. Compared to the fourteenth embodiment, the molecular arrangement when no voltage is applied is reversed (with respect to the horizontal alignment). Vertical alignment) and the dielectric anisotropy of the liquid crystal composition used is opposite (negative to positive). As described above, in the LCD of the present invention, when a voltage is applied, the refractive index with respect to the polarization component in the electrode stripe direction and the direction orthogonal thereto is such that the extraordinary light refractive index n _e and the ordinary light refractive index n _{0 of the} liquid crystal molecules are constant (in one direction or more). ), The diffraction grating is formed in the liquid crystal layer, and the effect of scattering parallel light can be obtained. If this effect is obtained for polarized light components in two orthogonal directions, unpolarized light can be scattered and high contrast characteristics can be obtained. Such a structure can be easily realized by using a liquid crystal composition having a negative dielectric anisotropy for initial vertical alignment in which the degree of freedom of liquid crystal molecules in the tilt direction (tilt direction and tilt down direction) is infinite. .

A voltage was applied to the LCD thus obtained through a TFT, and the electro-optical characteristics (transmittance-applied voltage curve) were measured by the method shown in Example 1. The measurement result is shown in FIG. When no voltage was applied (0 V was applied), the transmittance was about 80%, showing a bright transmittance characteristic. Also,
When the applied voltage was 3.8 V or higher, the minimum transmittance was 0.2%, and a good light scattering state was obtained. Further, as is clear from the figure, there was no hysteresis in the electro-optical characteristics. Also, when the response speed was measured at an applied voltage of 3.8 V and 0 V, a very fast value of 10 msec for rising and 20 msec for falling was obtained.

Example 16 A projection type liquid crystal display device was produced using the LCD obtained in Example 15. The structure is shown in FIG. The light source light from the metal halide lamp 25 is converted into parallel light by the schlieren lens 26, and the liquid crystal cell 27 and the condenser lens 28.
After that, the image is projected on the screen 31 by the projection lens unit 30. Drive device 32 and video signal output device 3
The image input to the liquid crystal cell 27 by the screen 3 is displayed on the screen 3
It is enlarged to 1 and displayed. The LCD of the present invention can control the optical path of parallel light by going straight or by scattering and electric field.
Therefore, as shown in the figure, an arbitrary image can be displayed on the screen 31 by using the Schlieren optical system.
In the present embodiment, a diaphragm (5 mmφ) 29 is provided at the focus position of the condenser lens 28 to project only the straight light of the parallel light incident on the liquid crystal cell 31, and the light scattered by the liquid crystal cell 31 is The configuration is cut off.

When a monochrome video signal image was projected about 30 times by using the obtained projection type liquid crystal display device, it was found that the contrast ratio was an extremely high value of about 200: 1. Also, an extremely bright display was obtained.

Example 17 A projection type liquid crystal display device was produced using the three LCDs obtained in Example 15. The structure is shown in FIG. In this embodiment, a white light source 37 including three wavelengths of RGB is used as a light source. The white light source 37 is divided into RGB wavelengths by using dichroic mirrors 34 and 35 and a total reflection mirror 36, and three liquid crystal cells are used. It is incident on 27a, 27b, and 27c. By doing so, it becomes possible to control the optical path for each wavelength. Therefore, color display can be realized. The dichroic mirror 34 transmits the red wavelength and totally reflects the green and blue wavelengths, and the dichroic mirror 35 transmits the blue wavelength and totally reflects the red and green wavelengths.

When a full-color video signal image was projected about 30 times by using the obtained projection type liquid crystal display device, it was found that the contrast ratio was an extremely high value of about 180: 1. Also, an extremely bright display was obtained.

Example 18 An LC was prepared in the same manner as in Example 15 except that as the upper substrate, a solid-state electrode made of ITO was formed on a color filter and a color filter substrate made of RGB was used.
I got D. Using this LCD, a projection type liquid crystal display device was produced in the same structure as in Example 16. Color display can be realized by providing a color filter.

When a full-color video signal image was projected about 30 times using the obtained projection type liquid crystal display device, it was found that the contrast ratio was an extremely high value of about 160: 1. Also, an extremely bright display was obtained.

[0115]

L comprising the nematic liquid crystal layer of the present invention
In the CD, the conductor portion and the non-conductor portion are made to face each other in a partial area in each pixel, and the width of the narrowest portion of the non-conductor portion is set to be S, and the CDs of both substrates arranged to face each other are arranged. Since the relationship of D ≧ S / 2 is satisfied when the electrode interval is D, the light transmission state is set by applying a uniform liquid crystal molecule arrangement, and the electric field direction of two or more directions is applied. A light scattering state can be realized by the refraction lens effect and the diffraction grating effect. As a result, without the need for media other than liquid crystal,
An LCD having excellent light scattering characteristics can be obtained. Particularly, when the liquid crystal molecules forming the liquid crystal layer form a splay alignment in the state where no voltage is applied, and when the tilt direction when the electric field is applied to the liquid crystal layer can be two or more directions, excellent scattering characteristics can be obtained.

The LCD of the present invention has an electrode structure of "nested structure", "nested structure with gap", "overlapping nest", "stripe nest with gap" or "overlapping stripe nest" so that it is slanted. The electric field can be easily formed so as to be contradictory for each fine region. As a result, an LCD having a high light scattering property, a low driving voltage, a bright, high contrast ratio, and an excellent gradation property, and an LCD having an extremely wide viewing angle dependency without a viewing angle inversion even when gradation display is performed.
Is obtained.

Such an effect is practically maintained by mixing fine particles having a diameter shorter than the electrode interval D into the gap between the substrates or providing a projection shorter than the electrode gap D on at least one of the substrates. be able to. Further, by forming a light-transmitting protective film having a refractive index of 0.9 to 1.1 times the refractive index of the electrode material on the electrode, it is possible to improve the transmittance and the contrast when no voltage is applied.

In the liquid crystal display device of the present invention, particularly by applying the above-mentioned LCD to the projection type liquid crystal display device, an extremely high contrast ratio and an extremely bright display can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention, in which (a) is a perspective view of an electrode and (b) is a cross-sectional view of a liquid crystal cell.

FIG. 2 is a diagram for explaining an electrode structure of the present invention.

3A and 3B are views for explaining a pretilt angle, where FIG. 3A is a schematic sectional view and FIG. 3B is a schematic plan view.

FIG. 4 is a diagram for explaining a uniform arrangement,
(A) is a schematic plan view, and (b) is a schematic cross-sectional view.

FIG. 5 is a schematic cross-sectional view illustrating the behavior of liquid crystal molecules in a uniform twist alignment when a voltage is applied.

FIG. 6 is a schematic plan view illustrating a uniform twist arrangement.

FIG. 7 is a curve diagram illustrating the relationship between applied voltage and transmittance.

FIG. 8 is a schematic plan view illustrating a uniform twist arrangement.

9A and 9B are views for explaining a spray arrangement, in which FIG. 9A is a schematic plan view and FIG. 9B is a schematic cross-sectional view.

FIG. 10 is a schematic plan view illustrating a splay twist arrangement.

FIG. 11 is a schematic plan view illustrating a splay twist arrangement.

FIG. 12 is a schematic cross-sectional view illustrating the behavior of liquid crystal molecules in a splay alignment depending on the presence / absence of an applied voltage, (a) to (c) showing no voltage applied, and (d) to (f) showing no voltage applied. .

FIG. 13 is a diagram illustrating an LCD according to an embodiment,
(A) is a perspective view of an electrode structure, (b) is X in (a).
A schematic cross-sectional view taken along the line -X ', (c) is a schematic view showing a state of liquid crystal molecules when a voltage is applied.

FIG. 14 is a diagram illustrating an LCD of another embodiment,
(A) is a perspective view of an electrode structure, (b) is X in (a).
A schematic cross-sectional view taken along the line -X ', (c) is a schematic view showing a state of liquid crystal molecules when a voltage is applied.

FIG. 15 is a diagram illustrating an LCD of another embodiment,
(A) is a perspective view of an electrode structure, (b) is X in (a).
A schematic cross-sectional view taken along the line -X ', (c) is a schematic view showing a state of liquid crystal molecules when a voltage is applied.

FIG. 16 is a schematic view for explaining an LCD of another embodiment and showing a state of liquid crystal molecules when a voltage is applied.

FIG. 17 is a plan view illustrating the appearance shape of the wall shown in FIG. 13 (c).

FIG. 18 is a cross-sectional view of a liquid crystal cell for explaining the LCD of the embodiment.

FIG. 19 is a cross-sectional view of a liquid crystal cell for explaining an LCD of another embodiment.

FIG. 20 is a sectional view of a liquid crystal cell for explaining an LCD of another embodiment.

FIG. 21 is a diagram for explaining the function of a translucent insulating film.

FIG. 22 is a view for explaining an LCD of one embodiment, (a)
Is a perspective view of the electrodes, and (b) is a schematic view showing the orientation directions of the upper and lower substrates.

FIG. 23 is a diagram showing the relationship between the transmittance and the applied voltage curve of Example 1.

FIG. 24 is a view for explaining an LCD of one embodiment, (a)
Is a schematic diagram illustrating the electrode structure arrangement and the state of liquid crystal molecules,
(B) is a plan view of an upper electrode (common electrode), and (c) is a plan view of a lower electrode.

FIG. 25 is a view for explaining an LCD of another embodiment,
(A) is a plan view of an upper electrode (common electrode), and (b) is a plan view of a lower electrode.

FIG. 26 is a view for explaining an LCD of another embodiment,
(A) is a plan view of an upper electrode (common electrode), and (b) is a plan view of a lower electrode.

FIG. 27 is a diagram showing the relationship between the transmittance and the applied voltage curve in Examples 3 to 7.

28A and 28B are diagrams for explaining an LCD using a translucent insulating film, in which FIG. 28A is a schematic diagram illustrating an electrode structure arrangement and a state of liquid crystal molecules, and FIG. 28B is a plan view of an upper electrode (common electrode). , (C)
[Fig. 4] is a plan view of a lower electrode.

FIG. 29 is a diagram showing the relationship between the transmittance and the applied voltage curve in Examples 8 to 12.

FIG. 30 is a schematic diagram illustrating an electrode structure arrangement and a state of liquid crystal molecules of an example in which fine particles are formed on a substrate surface.

FIG. 31 is a view for explaining an LCD of one embodiment, (a)
Is a schematic diagram illustrating the electrode structure arrangement and the state of liquid crystal molecules,
(B) is a plan view of an upper electrode (common electrode), (c) is a plan view of a lower electrode, and (d) is a schematic view for explaining a state of liquid crystal molecules.

FIG. 32 is a diagram showing a relationship between transmittance-applied voltage curves of LCDs of Example 14 and Example 15.

FIG. 33 is a view for explaining the LCD of Example 15;
(A) is a figure which shows the liquid crystal molecule arrangement | positioning planarly viewed when a voltage is not applied, (b) is a figure which shows the liquid crystal molecule arrangement | positioning planarly viewed when a voltage is applied.

FIG. 34 is a diagram showing a projection type liquid crystal display device in Example 16;

FIG. 35 is a diagram showing a projection type liquid crystal display device in Example 17;

36A and 36B are views for explaining a conventional LCD, wherein FIG. 36A is a schematic cross-sectional view of a capsule-like structure, and FIG. 36B is a schematic cross-sectional view of a fibrous polymer structure.

[Explanation of symbols]

1, 2 ... substrate, 3 ... polymer, 4, 6 ... liquid crystal, 5 ... fibrous polymer, 11 ... upper substrate, 12
……… Lower substrate, 13 ……… Upper electrode, 14 ……… Lower electrode,
15 ... upper alignment film, 16 ... lower alignment film, 17 ...
... upper translucent insulating film, 18 lower translucent insulating film, 19
...... Switching element, 20 ………… Liquid crystal layer, 21 …………
Power supply, 22 ......... Particles, 23 ......... Gate lines, 24 ...
…… Signal line, 25 ……… Metal halide lamp, 26…
…… Schlieren lens, 27 ………… Liquid crystal cell, 28…
...... Condensing lens, 29 ………… Aperture, 30 ………… Projection lens unit, 31 ………… Screen, 32 ………… Drive device, 33 ………… Video signal output device, 34, 35 ……
Diochroic mirror, 36 ......... Total reflection mirror, 3
7 ... White light source.

Front page continued (72) Inventor Hitoshi Hato 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Toshiba Yokohama Works (72) Inventor Masumi Okamoto 8 Shinsita-cho, Isogo-ku, Yokohama, Kanagawa Toshiba Toshiba Corporation In-house (72) Inventor Tsuyoshi Oyama 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Toshiba Yokohama Works (56) References JP-A-4-119321 (JP, A) JP-A-6-194656 (JP, A) ) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/13-1/141

Claims (11)

(57) [Claims] 1. A and the substrate with opposing electrodes arranged, the substrate Ri Do from the liquid crystal layer and composed of sandwiched nematic liquid crystal composition between the oppositely disposed electrodes with board is for each pixel as an electrode structure The width of the widest part is 50 μm or less
The liquid crystal display of the width of the widest part and der Ru conductor portions each having a region comprising a non-conductive portions Ru der <br/> 50 [mu] m or less
In the element, between the substrates arranged opposite to each other, the conductor portion and the non-conductor portion are opposed to each other in at least a part of the pixel in each pixel, and the non-conductor portion is Supposing that the width of the narrowest part is S and the electrode interval between the two substrates arranged to face each other is D, the relationship of D ≧ S / 2 is satisfied .
Ri, the liquid crystal layer, the tilt directions in two directions when an electric field is applied
Fine particles composed of a liquid crystal composition having a molecular arrangement that can be taken as described above and having a diameter shorter than the electrode interval D in the gap between both substrates.
A liquid crystal display device characterized by being mixed with a child . 2. The liquid crystal display element according to claim 1, wherein an oblique electric field is at least within one pixel between the two substrates arranged to face each other with respect to a vertical normal direction between the two substrates.
The liquid crystal molecules are formed in two or more directions, and the liquid crystal molecules forming the liquid crystal layer are in a splay arrangement when no voltage is applied, and have a tilting up or tilting down degree of freedom in two or more directions when a voltage is applied. Liquid crystal display device characterized by. In the liquid crystal display device 3. A process according to claim 1 or claim 2 Symbol mounting, at least one electrode substrate with the oppositely disposed,
The width of the widest part is 30 μm or less, the nematic liquid crystal composition has a means for inducing a tilt alignment to be aligned in the long-axis direction of liquid crystal molecules on the surface of the substrate, and the two substrates the crossing angle of the liquid crystal molecular alignment direction of the above and θ (0 ° ≦ θ ≦ 90 °), Ruth ist angle KOR so as to uniform twist orientations of LC and ψ by the pretilt angle on the two substrate surface Then , with no electric field applied to the liquid crystal layer, ψ is ± θ (where,
When the twist direction is counterclockwise, it is +, and when it is clockwise, it is −. )
, The liquid crystal twist angle ω is ± θ + 180 ° or ± θ
A liquid crystal display device, characterized in that the liquid crystal twist angle ω is ± θ (the above is the same order as the compound sign) when −180 ° and ψ is ± (θ−180 °). 4. A liquid crystal display device according to any one of claims 1 to 3, the substrates which are the opposite arrangement, when viewing the cross section of the element normal direction of the two substrates electrodes , conductive portions of the lower substrate
As not to overlap the width of the portion which does not overlap the conductive portions of the upper Chi substrate RE, the conductor portion of the inner lower substrate of the conductor portion of the upper group <br/> plate
Is FE, the width of both substrates is a conductor portion is EE, the width of both substrates is a non-conductor portion is SS, and at least each pixel has a portion of the width of RE or FE of both substrates.
When the conductor parts are electrically connected to each other, RE, SS, FE, SS, RE, SS, FE, SS, ...
And across the SS RE and FE are electrode structures comprising a cross section that is arranged in order to alternately, before Symbol nematic liquid crystal composition, a tilted alignment to align the liquid crystal molecules long axis in one direction on the substrate surface It has a means for inducing, the crossing angle of the liquid crystal molecule alignment direction on the two substrates is θ (0 ° ≤ θ ≤ 90 °), and the liquid crystal composition by the tilt alignment on the surface of the two substrates. things and Ri der Ruth ist angle ψ KOR so as to uniform twist arrangement,
In a state where no electric field is applied to the liquid crystal composition, wherein ψ is ± theta
(Here, when the twist direction is counterclockwise +, and when it is clockwise-), the twist angle ω of the liquid crystal is ± θ + 180 ° or ± θ−180 °, and ψ is ± (θ− 180 °)
At the time, the liquid crystal display element is characterized in that the twist angle ω of the liquid crystal is ± θ (the same as above in the double sign order). 5. Any one of claims 1 to 3
In the described liquid crystal display element , The oppositely arranged groups
Check the cross-sectional shape of the plate in the element normal direction of both substrate electrodes.
Of the conductors on the lower board,
The width of the part that does not become RE is the lower part of the conductor part of the upper substrate.
The width of the part that does not overlap the conductor part of the plate is FE, and both boards are
The width of the conductor portion is EE, and both substrates are non-conductor portions.
The width is set to SS, and at least for each pixel,
The conductor part having a portion of the width of RE or FE is
When each is electrically connected, RE ・ EE ・ FE ・ EE ・ RE ・ EE ・ FE ・ EE ・ ...
And EE sandwiched between RE and FE are alternately arranged in order
It is a shape electrode structure, The nematic liquid crystal composition is a liquid crystal on the substrate surface.
A hand that induces a tilt alignment that aligns the molecular long axis in one direction.
Has steps,  2 Of the alignment direction of liquid crystal molecules on a single substrate
The intersection angle is θ (  0 ° ≤ θ ≤ 90 °),  2 The surface of the substrate
The liquid crystal composition is made uniform by the tilt alignment above.
The twist angle that is decided to be arranged in the twist is ψ,
In the state where no electric field is applied to the liquid crystal composition, ψ is ± θ
(Here, when the twist direction is counterclockwise +, and when it is clockwise-
To do. ), The liquid crystal twist angle ω is ± θ + 180 °
Or ± θ- 180 And ψ is ± (θ− 180 °)
When, the twist angle ω of the liquid crystal is ± θ (above compound number same order)
A liquid crystal display element characterized by the following. 6. Any one of claims 1 to 3
In the liquid crystal display element described, The two substrates arranged opposite to each other are the element method of the both substrate electrodes.
When looking at the cross-sectional shape in the line direction,
The width of the part that does not overlap the conductor part of the upper substrate is RE,
A part of the conductor part of the board that does not overlap the conductor part of the lower board
Is FE, the width of both boards is the conductive part, EE,
The width of the non-conductor part of the plate is SS, and at least each image is
Each substrate has a part of the width of the RE or FE of both the boards.
The conductive parts are electrically connected to each other.
When RE ・ FE ・ RE ・ FE ・ RE ・ FE ・ RE ・ FE ・ ...
And RE and FE have a cross-sectional shape in which they are alternately arranged in order.
Electrode structure, The nematic liquid crystal composition is a liquid crystal on the substrate surface.
A hand that induces a tilt alignment that aligns the molecular long axis in one direction.
Has steps,  2 Of the alignment direction of liquid crystal molecules on a single substrate
The intersection angle is θ (  0 ° ≤ θ ≤ 90 °),  2 The surface of the substrate
The liquid crystal composition is made uniform by the tilt alignment above.
The twist angle that is decided to be arranged in the twist is ψ,
In the state where no electric field is applied to the liquid crystal composition, ψ is ± θ
(Here, when the twist direction is counterclockwise +, and when it is clockwise-
To do. ), The liquid crystal twist angle ω is ± θ + 180 °
Or ± θ- 180 And ψ is ± (θ− 180 °)
When, the twist angle ω of the liquid crystal is ± θ (above compound number same order)
A liquid crystal display element characterized by the following. 7. The liquid crystal display device according to any one of claims 1 to 6, wherein the liquid crystal composition a liquid crystal having a positive or negative dielectric anisotropy, when an electric field is applied to The tilt directions of two or more possible directions are a tilt-up direction in the case of the liquid crystal having the positive dielectric anisotropy, and a tilt-down direction in the case of the liquid crystal having the negative dielectric anisotropy. liquid crystal molecular alignment in the substrate, the difference in the pretilt angle of the liquid crystal is a liquid crystal molecule array to 0.5 ° or less, the liquid direction to obtain the pretilt angle α0 is ing from the bend-shaped alignment in the same direction at upper and lower crystal molecules A liquid crystal display element, which is an array. 8. The liquid crystal display device according to any one of claims 1 to 7, at least the conductive portion is a portion and the non-conductive portion of each pixel electrode structure both the two substrates for each pixel A liquid crystal display element having a striped shape. 9. Any one of claims 1 to 8.
In the liquid crystal display element described, A protrusion shorter than the electrode interval D is provided on at least one of the both substrates.
A liquid crystal display device characterized by being provided in. 10. A substrate with electrodes arranged to face each other, and
Liquid consisting of nematic liquid crystal composition sandwiched between substrates
Crystal layer, and the substrate with electrodes arranged oppositely is electrically charged.
The width of the widest portion in each pixel as a pole structure 50 mu m or more
The width of the widest portion and the conductor portion is below the following 50 mu m
A liquid crystal surface having regions each consisting of a certain non-conductor part
In the element shown in the figure , at least one screen is placed between the two substrates arranged to face each other.
For each element, the conductive portion and the non-conductive portion are partially formed in the pixel.
The body part is opposite, and the non-conductor part is the narrowest
The width of the portion is S, and between the electrodes of the two substrates arranged to face each other.
When the distance is D, the relation of D ≧ S / 2 is satisfied.
Ri, the liquid crystal layer, the tilt directions in two directions when an electric field is applied
It is composed of a liquid crystal composition having a molecular arrangement that can be taken as described above, and a transparent protective film is formed on the electrode, and the refractive index of this transparent protective film is 0.9 to 1.1 times the refractive index of the electrode material. Liquid crystal display device characterized by. 11. A liquid crystal display element, means for injecting parallel light to the liquid crystal display element, means for controlling the incident parallel light by the liquid crystal display element, and means for controlling the traveling direction of the controlled light. 11. A projection type liquid crystal display device comprising a means for using an optical system for projecting light in a part of the directions, wherein the liquid crystal display element is the liquid crystal display element according to any one of claims 1 to 10. And a liquid crystal display device.