JPH11202300A - Liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display element capable of the display of high contrast. SOLUTION: This element 1 is provided with a substrate 2 forming an electrode 4 on at least one main side, a liquid crystal layer 7 having a liquid crystal microcapsule 6 containing a liquid crystal material 10 with transparent coating while being formed on the side of this substrate where the electrode 4 is formed, and a counter electrode 5 provided on this liquid crystal layer 7. In this case, the liquid crystal material 10 has a laminated structure laminating a first liquid crystal microcapsule layer 8 formed by showing helical structure in the liquid crystal microcapsule 6 and arranging the liquid crystal microcapsule so as to turn the helical axis of the liquid crystal layer 7 in a first direction and a second liquid crystal microcapsule layer 8 formed by arranging the liquid crystal microcapsule 6 so as to turn the helical axis in a second direction, and the first and second directions are practically parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal display device.

[0002]

2. Description of the Related Art Many liquid crystal display elements have been proposed as display elements used in displays of information equipment. Among these liquid crystal display elements, at present, the TN mode (twisted mode) disclosed in JP-A-47-11737 is disclosed.
Nematic mode) and a liquid crystal display device using a nematic liquid crystal, such as a STN mode (super twisted nematic mode) disclosed in JP-A-60-107020, are widely used.

In the TN mode and STN mode liquid crystal display devices, the alignment of liquid crystal molecules is initially
The structure is twisted around 90 ° and around 260 °, respectively. Therefore, the light incident on the element is emitted after receiving a change in the polarization state due to the twisted structure of the liquid crystal molecule arrangement and the birefringence.

When a voltage is applied to the liquid crystal layer, the liquid crystal molecules rearrange in the direction of the electric field, and the above-mentioned twisted structure disappears. As a result, the birefringence is lost, and the incident light exits without changing the polarization state. Therefore, by using a structure in which the element is sandwiched between two linear polarizers, the optical properties of the liquid crystal layer change according to the application / non-application of the voltage, and the change in the intensity of the emitted light is observed. The TN mode and the STN mode are display methods for obtaining a light and dark contrast based on this operation principle.

[0005] The liquid crystal display devices of these display systems are CRTs.
(Cathode ray tube) It has an advantage that it consumes much less power than a display and can be made thinner, and is widely used in office information devices such as personal computers and word processors.

However, since the liquid crystal display device of the above-mentioned display system uses a polarizer, it cannot be said that the incident light is effectively used. Therefore, in many of the above liquid crystal display devices, a light source (backlight) is provided behind the liquid crystal display element in order to secure the intensity of emitted light. Further, in a liquid crystal display device provided with a color filter, since the light transmittance is further reduced, a more powerful light source is required.

However, the power of this light source is comparable to the power consumption of a liquid crystal display device including a drive circuit. Therefore, the liquid crystal display device of the above display method is not suitable for a display of a portable information device powered by a battery.

That is, in the conventional display type liquid crystal display device, the improvement in brightness and the reduction in power consumption have a trade-off relationship regardless of whether the display is a color display or a monochrome display.

Further, in such a liquid crystal display device, since a fluorescent lamp is generally used as a backlight, eyestrain is great when the display is continued for a long time.
Not desirable. Therefore, it is desired to develop a display system which can be applied to a reflection type liquid crystal display element which does not require a backlight and has high light use efficiency.

Also, when the liquid crystal display device is used as a projection type display, it is possible to reduce the size of the device, extend the service life, and save power of the entire device by increasing the light transmittance. Therefore, it is desired to develop a display system with high light use efficiency even in a projection type liquid crystal display device.

In response to such demands, various display systems without using a polarizer have been proposed. For example, as a display method using no polarizer, NCAP (Nematic Curvilinea) is used.
r Aligned Phase) or PDLC (Polymer Disperse)
d Liquid Crystal) is known. In this display method, a nematic liquid crystal having a positive dielectric anisotropy is dispersed in a polymer matrix into particles having a diameter of about several μm to form a liquid crystal layer. The liquid crystal is selected such that the refractive index for ordinary light is almost the same as that of the polymer matrix, and the refractive index for extraordinary light is different from that of the polymer matrix.

According to this display method, in the initial state, the liquid crystal molecules in each liquid crystal particle have a distorted alignment structure, and the alignment direction is different between the liquid crystal particles. There is a difference in the refractive index with the molecular matrix, which results in light scattering like frosted glass.

When a sufficient voltage is applied to the liquid crystal layer, rearrangement of liquid crystal molecules occurs in each liquid crystal particle, and a refractive index between the liquid crystal particles and the polymer matrix with respect to light incident perpendicularly to the liquid crystal layer. Are equal. As a result, there is no refraction or reflection at the interface between the liquid crystal particles and the polymer matrix, and the liquid crystal particles are in a transmission state. The incident light does not need to be linear light.

The above-mentioned display system is different from a display system using a liquid crystal microcapsule described later, in which liquid crystal is dispersed in a medium. The liquid crystal display device of this display type can be easily formed by enclosing the polymer matrix in which the liquid crystal particles are dispersed in a glass cell used for a general liquid crystal display device or by applying the polymer matrix to a substrate. Can be.

However, when the orientation of the liquid crystal is adjusted by post-processing such as stretching to enhance the contrast, or when the film is laminated with a conductive polymer film, the strength of the liquid crystal layer cannot be said to be sufficient. In addition, there is no problem when performing display by generating a white-black change by adding a transparent-opaque change or a black dichroic dye, but a color filter is required when performing a color display. Therefore, the light use efficiency cannot be increased.

Another display method without using a polarizer is as follows.
A display method using a guest-host liquid crystal in which a guest dichroic dye is added to a host liquid crystal material is known. According to this display method, the light transmittance is controlled by changing the orientation direction of the dichroic dye. That is, by applying a voltage to the liquid crystal layer, the liquid crystal molecules arranged in parallel with the substrate surface in the initial state are arranged vertically with respect to the substrate surface, and the direction of the dichroic dye is changed accordingly. The transmittance is controlled.

According to the above-mentioned display system, it is possible to make a transparent-color change without using a polarizing plate. Also,
According to this display method, for example, color display can be performed without using a color filter by laminating cyan, magenta, and yellow liquid crystal layers with an intermediate substrate interposed therebetween.

However, since the dichroic dye has a uniaxial light absorption axis, it cannot absorb a polarized light component perpendicular to the light absorption axis. The dichroic dye has low solubility in the host liquid crystal material and low molar extinction coefficient. Therefore, in the above display method, it is impossible to display with high contrast.

In order to realize a liquid crystal display device capable of displaying with higher contrast by using a guest / host liquid crystal,
Various attempts have been made. For example, Journal of Applied Physics (J. Appl. Phys.), 45
Vol., 4718-4723 (1974).
A hit-Taylor type guest-host liquid crystal display device is disclosed. In this liquid crystal display device, a mixture of a liquid crystal exhibiting a chiral nematic phase and a dichroic dye is used for a liquid crystal layer. In this device, light absorption by the dye occurs efficiently due to the twisted structure caused by the chiral nematic phase, so that high display contrast can be obtained in principle without a polarizer.

However, in order to achieve high contrast in this liquid crystal display device, it is necessary to make the helical pitch of the liquid crystal molecule arrangement exhibiting a chiral nematic phase on the order of the wavelength of light. When the helical pitch is shortened in this way, a large number of discrimination lines are generated, thereby deteriorating the display quality, and at the same time, a hysteresis phenomenon occurs, so that the response speed to voltage application becomes extremely slow. Therefore, the above-described TN mode and ST
Compared to N-mode liquid crystal display devices, they are less practical.

As another display device using a guest-host liquid crystal, a liquid crystal display device using a liquid crystal microcapsule is known. Attempts have been made to obtain a color liquid crystal display device having high light use efficiency by using the guest-host liquid crystal microcapsules. For example, guest-host liquid crystal microcapsules having different absorption wavelengths are prepared and mixed to form a liquid crystal layer (Japanese Patent Laid-Open No. 58-148885). (Japanese Patent Application No. 7-56086) is known in which the liquid crystal layers are laminated without using an intermediate substrate such as glass or plastic.

Thus, in a liquid crystal display device using liquid crystal microcapsules, it is not necessary to use a polarizer or the like. Therefore, light use efficiency is increased, and high display contrast is expected. However, at the moment,
In a liquid crystal display device using liquid crystal microcapsules,
High display contrast has not yet been obtained.

[0023]

As described above, in a liquid crystal display device using a guest-host liquid crystal, high display contrast has not been obtained. SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device capable of displaying with high contrast.

[0024]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has a substrate having electrodes formed on at least one main surface thereof, and a substrate formed on the surface of the substrate having electrodes formed thereon. It comprises a liquid crystal layer having a liquid crystal microcapsule containing a liquid crystal material in a transparent film, and a counter electrode provided on the liquid crystal layer, wherein the liquid crystal material exhibits a helical structure in the liquid crystal microcapsule, The liquid crystal layer
A first liquid crystal microcapsule layer in which the liquid crystal microcapsules are arranged so that the spiral axis is oriented in a first direction; and a liquid crystal microcapsule in which the liquid crystal microcapsules are arranged so that the spiral axis is oriented in a second direction. And a second liquid crystal microcapsule layer, wherein the first and second directions are substantially parallel.

Preferred embodiments of the above liquid crystal display device will be described below. (1) The first and second directions are substantially parallel to a substrate surface.

(2) The liquid crystal microcapsules have an anisotropic shape. The present invention also provides a substrate having electrodes formed on at least one main surface thereof, a liquid crystal layer provided on a surface of the substrate having electrodes formed thereon, the liquid crystal layer including a liquid crystal material, and a counter electrode provided on the liquid crystal layer. Wherein the liquid crystal layer is provided with a first liquid crystal region in which a liquid crystal material is aligned in a first alignment direction and a liquid crystal material adjacent to the first liquid crystal region in a direction parallel to a substrate surface. A second liquid crystal region aligned in a second alignment direction, wherein the first and second liquid crystal regions are regularly arranged, and the first alignment direction is different from the second alignment direction. The present invention provides a liquid crystal display device characterized by the following.

Preferred embodiments of the liquid crystal display device are described below. (1) An alignment film is provided on each of the electrodes and the counter electrode. (2) The liquid crystal layer is composed of liquid crystal microcapsules containing a liquid crystal material in a transparent film.

(3) The liquid crystal microcapsules have an anisotropic shape. Further, the present invention includes a substrate having electrodes formed on at least one main surface thereof, a liquid crystal layer formed on a surface of the substrate having the electrodes formed thereon, and a counter electrode provided on the liquid crystal layer, The liquid crystal layer has a laminated structure in which first and second liquid crystal microcapsule layers each including a liquid crystal microcapsule containing a liquid crystal material in a transparent film are laminated, and any one of the first and second liquid crystal microcapsule layers is used. The liquid crystal microcapsules constituting one of them provide a liquid crystal display element characterized in that the liquid crystal material exhibits radial alignment.

Preferred embodiments of the above liquid crystal display device will be described below. (1) The liquid crystal microcapsules forming the other of the first and second liquid crystal microcapsule layers have a liquid crystal material exhibiting radial alignment.

(2) The liquid crystal microcapsules forming the other of the first and second liquid crystal microcapsule layers have a liquid crystal material exhibiting a bipolar orientation. (3) The liquid crystal microcapsules constituting the other of the first and second liquid crystal microcapsule layers have a liquid crystal material exhibiting an axial alignment. (4) The liquid crystal microcapsules forming the other of the first and second liquid crystal microcapsule layers have a liquid crystal material having a helical structure.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 shows the first embodiment of the present invention.
1 shows a cross-sectional view of a liquid crystal display element according to the embodiment. In FIG. 1, a liquid crystal display element 1 is disposed so as to face a substrate 2 having an electrode 4 formed on one main surface and a surface of the substrate 2 on which the electrode 4 is formed, and has an electrode 5 formed on the opposing surface. Substrate 3
And a liquid crystal layer 7 sandwiched between the substrates 2 and 3.

In the liquid crystal display element 1, the substrates 2, 3
As the electrode 4, a transparent conductive film such as ITO or a metal film such as aluminum is used as the electrode 4. The substrate 3 is not necessarily provided, and a protective film such as a transparent resin may be provided instead. As the electrode 5, a transparent conductive film such as ITO is used.

In the liquid crystal display element 1, the liquid crystal layer 7 is composed of the liquid crystal microcapsules 6 in which the liquid crystal material 10 is covered by the transparent film 37. The liquid crystal microcapsules 6 have a layered structure in the liquid crystal layer 7 and form liquid crystal microcapsule layers 8 and 9. In each liquid crystal microcapsule 6, the liquid crystal material 10 is arranged in a spiral and has a spiral axis.

In the liquid crystal microcapsule 6, a mixture of a liquid crystal compound and a chiral agent can be used as the liquid crystal material 10. As the liquid crystal compound used for the liquid crystal material 10, a fluorine-based liquid crystal compound, a cyano-based liquid crystal compound, an ester-based liquid crystal compound, or the like can be used. According to the first embodiment of the present invention, it is preferable that the dielectric anisotropy is positive because light is absorbed when no voltage is applied.

As the chiral agent used for the liquid crystal material 10, a compound having a chemical structure similar to that of the above-mentioned liquid crystal compound and having an asymmetric atom between the core and the spacer can be used. The weight ratio of the chiral agent to the liquid crystal compound is preferably 0.01 to 50% by weight, more preferably 1 to 30% by weight. When the weight ratio of the chiral agent is less than the lower limit, the liquid crystal material 10 may not be able to be favorably arranged in a spiral. In addition, when the weight ratio of the chiral agent exceeds the upper limit, there is a possibility that problems such as an excessive increase in the driving voltage and occurrence of an optical hysteresis at ON / OFF.

The chiral polarity of the liquid crystal material 10 may be left or right. However, in containers that contain liquids such as water,
When a liquid mixture of the liquid crystal material 10 and the raw material of the transparent film 37 is dropped in the form of droplets to form a liquid flow that rotates in a container, the liquid crystal microcapsule 6 is formed. It is desirable that the direction is opposite to the polarity.
This is for the following reason.

When the liquid mixture in the form of droplets changes into the liquid crystal microcapsules 10, the liquid crystal material 10 is generated in the liquid droplets on which the transparent film 37 is being formed as the liquid flow rotates. Due to the influence of the inertial force (Coriolis force), the liquid flow tends to rotate in a direction opposite to the rotation direction. for that reason,
The transparent film 37 is formed on the inner wall thereof under the influence of the rotation of the liquid crystal material 10. The transparent film 37 thus formed may have a weak twist structure inducing property to the liquid crystal material 10 in some cases.

When the direction of rotation of the liquid flow is the same as the chiral polarity of the liquid crystal material 10, the twisted structure induced by the transparent coating 37 is opposite to the chiral polarity of the liquid crystal material 10, and as a result, The twisted structure organic property may not be expressed. On the other hand, when the rotation direction of the liquid flow is opposite to the chiral polarity of the liquid crystal material 10, the twisted structure induced by the transparent coating 37 has the same direction as the chiral polarity of the liquid crystal material 10. Therefore, the above problem does not occur.

The liquid crystal material 10 usually contains a dichroic dye. In a liquid crystal display device using a dichroic dye, when light absorption occurs when no voltage is applied, the display color becomes whitish, and thus reduction of light scattering is particularly desired.

As the dichroic dye, yellow dyes represented by the following chemical formulas (1) to (9),
0) to (17) and cyan dyes represented by the following chemical formulas (18) to (21).

[0041]

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[0042]

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[0043]

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[0044]

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[0045]

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These dichroic dyes are preferably mixed at 0.01 to 10% by weight with respect to the liquid crystal compound.
More preferably, it is mixed at 1 to 5% by weight. If the mixing ratio of the dichroic dye is less than the lower limit, sufficient contrast cannot be obtained. If the mixing ratio is more than the upper limit, the coloring may remain even when voltage is applied, and the contrast may be reduced.

The transparent coating 37 containing the liquid crystal material 10
Examples of such heat include condensation polymers such as melamine resin, epoxy resin, urea resin, phenol resin, and furan resin, and three-dimensional crosslinked vinyl polymers such as styrene-divinylbenzene copolymer and methyl methacrylate-vinyl acrylate copolymer. A curable resin can be used.

As a material used for the transparent film 37,
Polyethylenes; Chlorinated polyethylenes; Ethylene copolymers such as ethylene / vinyl acetate copolymers, ethylene / acrylic acid / maleic anhydride copolymers; Polybutadienes; Polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate Polypropylene; Polyisobutylenes; Polyvinyl chlorides; Polyvinylidene chlorides; Polyvinyl acetates;
Polyvinyl alcohols; polyvinyl acetal; polyvinyl butyral; ethylene tetrafluoride resin; ethylene trifluoride chloride resin; ethylene propylene fluoride resin; vinylidene fluoride resin; vinyl fluoride resin; Tetrafluoride such as ethylene / perfluoroalkoxyethylene copolymer, ethylene tetrafluoride / perfluoroalkyl vinyl ether copolymer, ethylene tetrafluoride / hexafluoropropylene copolymer, ethylene tetrafluoride / ethylene copolymer Ethylene copolymer; Fluororesins such as fluorine-containing polybenzoxazole; Acrylic resins; Methacrylic resins such as polymethyl methacrylate; Polyacrylonitriles; Acrylonitrile copolymers such as acrylonitrile / butadiene / styrene copolymer; Kinds; halogenated Styrenes; styrene copolymers such as styrene-methacrylic acid copolymers and styrene-acrylonitrile copolymers; ionic polymers such as sodium polystyrene sulfonate and sodium polyacrylate; acetal resins; polyamides such as nylon 66; Gelatin; Arabic gum; Polycarbonates; Polyester carbonates; Cellulosic resins; Phenolic resins; Urea resins; Epoxy resins; Unsaturated polyester resins; Alkyd resins; Polyphenylene oxides; polyphenylene sulfides; polysulfones; polyphenylsulfones; silicone resins; polyimides; bismaleimide triazine resins; polyimide amides; Terusurufon like; polymethyl pentene acids; polyetheretherketones; polyetherimides, polyvinyl carbazoles; norbornene-based amorphous polyolefins; thermoplastic resin polyfumaric acid esters may also be mentioned.

The transparent coating 37 of the liquid crystal microcapsule 6
Is selected from the above thermosetting resins and thermoplastic resins.
It may be formed as a multilayer film using at least one kind of resin.
In this case, in order to improve the thermal stability of the liquid crystal microcapsules 6, it is preferable to use a thermosetting resin for the outermost shell of the transparent film 37.

The liquid crystal microcapsules 6 configured as described above can be prepared by an interfacial polymerization method, an in situ polymerization method, a hardening coating in liquid method, a phase separation method from an aqueous solution system, a phase separation method from an organic solution system, melting and dispersion. A cooling method, an air suspension method, a spray drying method, or the like can be used. The liquid crystal microcapsules 7 usually have an average particle size of 3 μm to 15 μm.
It is formed so that it is about.

FIGS. 2A and 2B are cross-sectional views of a liquid crystal microcapsule used in the liquid crystal display device according to the first embodiment of the present invention. In the liquid crystal microcapsules 6-1 and 6-2 shown in FIGS.
Indicates the orientation direction of the liquid crystal molecules. In addition, transparent film 3
7, a chiral agent and a dichroic dye (not shown) are included in addition to the liquid crystal molecules. As shown in FIGS. 2A and 2B, the liquid crystal molecules 12 are
-1, 6-2, it is arranged in a spiral with respect to the spiral axis 38.

According to the liquid crystal display element 1 according to the first embodiment of the present invention, the liquid crystal layer 7 is formed by laminating the liquid crystal microcapsules 6-1 and 6-2, so that a high display contrast is obtained. be able to. The reason will be described below.

FIGS. 2C, 2D and 2E are sectional views of liquid crystal microcapsules used in a conventional liquid crystal display device. The liquid crystal microcapsules 6-3, 6-4, and 6-5 shown in (c), (d), and (e) have a structure in which a liquid crystal material is included in a transparent film 37. Further, according to the conventional manufacturing method, FIGS. 2 (c), (d) and (e)
As shown in the figure, usually, liquid crystal microcapsules 6-3, 6-4
And 6-5 are spherically formed.

The liquid crystal microcapsules 6-3 to 6-5 shown in FIGS.
Are different. The difference in these orientations is due to the
Due to the degree of interaction between the liquid crystal molecules and the liquid crystal microcapsules. That is, when an appropriate interaction exists between the transparent film 37 and the liquid crystal molecules, the liquid crystal molecules exhibit bipolar alignment (e), and when the interaction is weak, the liquid crystal molecules exhibit radial alignment (c) or axial alignment (d). When the interaction is weak and the particle size is sufficiently large, radial orientation is exhibited. When the interaction is weak and the particle size is small, axial orientation is exhibited.

As described above, the liquid crystal molecules in the liquid crystal microcapsules can take various orientations. However, in an actual system, there is usually some interaction between the liquid crystal material 10 and the transparent film 37. In addition, the bipolar orientation has smaller strain elastic energy than the radial orientation or the axial orientation. Therefore,
In general liquid crystal microcapsules, the liquid crystal material 10 usually exhibits bipolar alignment.

When the orientation of the liquid crystal material 10 is of a bipolar type, various materials can be used for the liquid crystal material 10 and the transparent film 37, which is advantageous in manufacturing the element. Further, in the bipolar liquid crystal microcapsules 6-5 shown in FIG. 2E, the liquid crystal material 10 at the center of the capsule, which is considered to most contribute to display, is arranged in almost one direction. Therefore, the orientation of the liquid crystal material 10 is
The bipolar type shown in FIG. 2E is considered to be suitable.

However, in the liquid crystal microcapsule 106-3 shown in FIG. 2 (e), as described above, the liquid crystal material 10 at the center of the capsule is arranged in almost one direction, so that the polarization component in the arrangement direction is obtained. Can only be absorbed. That is, a polarized light component in a direction perpendicular to the arrangement direction of the liquid crystal material 10 cannot be used for display.

As a method of utilizing the above-mentioned polarized light component for display, a liquid crystal microcapsule 6-5 shown in FIG. 2E is parallel to the optical axis of the incident light so that the orientation directions of the respective liquid crystal materials 10 are orthogonal. It is conceivable to laminate in different directions.
According to this method, it is theoretically possible to absorb all polarization components. However, it is difficult to control the position of the liquid crystal microcapsules 6-5 and the alignment direction of the liquid crystal material 10 with high accuracy. Therefore, with this method, it was not possible to realize a light absorption efficiency of more than 50% at the center of the capsule, that is, to obtain a display performance with a contrast ratio of more than 2.

The present inventors arrange the liquid crystal microcapsules 6 in each of the liquid crystal microcapsule layers 8 and 9 such that the helical axis of the liquid crystal material 10 is oriented in one direction, so that the position of the liquid crystal microcapsules 6 can be improved. It was considered that the control of the alignment direction and the like of the liquid crystal material 10 could be performed with high accuracy, and the method was examined. As a result, for example, by forming the liquid crystal microcapsules 6 into an anisotropic shape,
It has been found that the above control can be performed with high accuracy.

Assuming that the liquid crystal microcapsules 6 have an anisotropic shape, that is, a shape having a major axis and a minor axis, FIG.
As shown in the figure, the spiral axis 38 is the liquid crystal microcapsule 6-2.
, The strain elastic energy of the liquid crystal material 10 is minimized. That is, by forming the liquid crystal microcapsules 6 in an anisotropic shape, the direction of the spiral axis 38 with respect to the liquid crystal microcapsules 6 can be controlled.

When a liquid crystal microcapsule 6-2 having an anisotropic shape is used, the liquid crystal microcapsule layer 8,
At the time of forming the liquid crystal microcapsules 6-2, by applying a process such as moving in one direction with a squeegee, moving in one direction by applying sound pressure of ultrasonic waves, or moving down by gravity. Can be arranged in a desired orientation. Therefore, by using the liquid crystal microcapsules 6-2 having an anisotropic shape, all the liquid crystal microcapsules 6-2 can be arranged such that the helical axes 38 thereof are oriented in one direction.

As described above, the liquid crystal microcapsule layer 8 or 9 is formed using the liquid crystal microcapsule 6-2 having an anisotropic shape.
Has been described. However, after forming the liquid crystal microcapsule layer 8 or 9 using the spherical liquid crystal microcapsules 6-1, the liquid crystal microcapsules 6-1 are anisotropically processed by stretching or the like. It may be deformed to a uniform shape.

According to the method described above, the position of the liquid crystal microcapsules 6 and the alignment direction of the liquid crystal material 10 can be controlled with high precision. However, in order to obtain high display contrast, it is necessary that the first and second liquid crystal microcapsule layers 8 and 9 absorb different polarized light components.

To realize this, for example, FIG.
(E) Bipolar liquid crystal microcapsules 6-5
May be used as an anisotropic shape. However, in this case, the long axis direction of the liquid crystal microcapsules 6-5 in the second liquid crystal microcapsule layer 8 is in relation to the long axis direction of the liquid crystal microcapsules 6-5 in the first liquid crystal microcapsule layer 9. They must be stacked vertically. That is, the first and second liquid crystal microcapsule layers 8 and 9 cannot be formed simultaneously.

On the other hand, according to the first embodiment of the present invention, the liquid crystal material 10 in the liquid crystal microcapsule 6 is spirally arranged as shown in FIG. The liquid crystal microcapsule layers 8 and 9 can be formed simultaneously. The reason will be described below.

The liquid crystal microcapsule 6 shown in FIG.
-2, when light is incident from the short axis direction, the dichroic dye can absorb only one direction of the polarized light component, so when the light is incident on the liquid crystal layer where the liquid crystal material exhibits a homogeneous alignment. Similarly, 50% of the light is ideally absorbed.

However, when the liquid crystal material exhibits a homogeneous orientation, the emitted polarized light component is perpendicular to the absorbed polarized light component, whereas the emitted liquid crystal microcapsule 6-2 shown in FIG. The polarization component to be absorbed is not necessarily perpendicular to the polarization component of the absorbed incident light. That is, in the liquid crystal microcapsule 6 shown in FIG. 2B, since the arrangement of the liquid crystal molecules 12 has a twisted structure, the polarized light component which is not absorbed is similar to the case where light is incident on the TN cell or the STN cell. The light is emitted with its polarization direction changed.

Therefore, the liquid crystal microcapsules 6
At −2, the orientation direction of the liquid crystal molecules 12 near the incident position is set to 45 ° with respect to the helical axis 38.
°, a 90 ° twist structure is formed. In addition,
The helical structure of the liquid crystal material 10 can be easily controlled by appropriately selecting the amount and type of the chiral agent described above. This makes it possible to emit a non-absorbable polarized component as a polarized component in the same direction as the absorbed polarized component.

By controlling the direction of polarization of the emitted polarized light component in this way, the liquid crystal microcapsules 6-2 can be
The polarization component transmitted through one liquid crystal microcapsule 6-2 can be absorbed by the other liquid crystal microcapsule 6-2 simply by stacking them so that the directions of the spiral axes 38 coincide with each other. Specifically, it becomes possible to absorb all polarization components.

In this case, the liquid crystal layer 7 is formed by separately forming the first and second liquid crystal layers 8 and 9 and transferring the other one to the other. 8, 9 can be formed simultaneously. As the method, for example, the liquid crystal microcapsules 6-2 having an anisotropic shape are continuously laminated to form the first and second liquid crystal layers 8 and 9 simultaneously, or a spherical liquid crystal microcapsule 6-2 is formed. After the first and second liquid crystal layers 8 and 9 are simultaneously formed by using the capsule 6-1, they may be formed by a method such as performing a stretching process.

As described above, according to the first embodiment of the present invention,
Helical axis 38 in first liquid crystal microcapsule layer 8
Is the helical axis 3 in the second liquid crystal microcapsule layer 9.
It has been described that high light absorption efficiency can be obtained when the angle is parallel to 8. However, the respective helical axes do not necessarily have to be completely parallel, and when the angles formed by these helical axes are in the range of 0 to 45 °, the above-described effects can be obtained.

Further, each spiral axis 38 preferably forms an angle of 45 ° or less with the substrate surface, and more preferably is parallel to the substrate surface. In this case, the orientation of the dichroic dye with respect to the optical axis of the incident light is optimized, and higher light absorption efficiency can be obtained.

Next, a second embodiment of the present invention will be described. FIG. 3 shows a sectional view of a liquid crystal display device according to the second embodiment of the present invention. In FIG. 3, the liquid crystal display element 1
Reference numeral 1 denotes a pair of substrates 2 and 3 arranged facing each other, electrodes 4 and 5 formed on the opposing surface of each substrate, and alignment films 13 to 16 formed on the electrodes 4 and 5, respectively. And a liquid crystal layer 7 sandwiched between a pair of substrates 2 and 3.

In the liquid crystal display element 11, the substrates 2,
As the electrode 3, a transparent substrate such as glass or plastic is used, and as the electrode 4, a transparent conductive film such as ITO or a metal film such as aluminum is used. As the electrode 5,
A transparent conductive film such as ITO is used. Also, the alignment film 13
No. to No. 16 are usually made of a material such as polyimide used as an alignment film.

In the liquid crystal display element 11, the liquid crystal layer 7
Is composed of a liquid crystal material 20 which is a mixture of the liquid crystal compound 12 and the dichroic dye 19 described in the first embodiment. The liquid crystal layer 7 includes liquid crystal regions 17 and 18 arranged adjacent to each other. According to the liquid crystal display element 11 according to the second embodiment of the present invention, the alignment direction of the liquid crystal material 20 is controlled by the alignment films 13 to 16 in these liquid crystal regions 1.
Control is performed differently between 7 and 18. Therefore, according to the liquid crystal display element 11, display with high contrast is possible. The reason will be described below.

As described in the first embodiment,
The light absorption axis of the dichroic dye is uniaxial. That is, even if a polarized light component in a predetermined polarization direction is absorbed by 100%, a polarized light component in a direction perpendicular thereto cannot be absorbed.

On the other hand, in the liquid crystal display element 11, the liquid crystal regions 17, in which the orientation directions of the liquid crystal material 20 differ,
18 are juxtaposed adjacently. Therefore, when light is incident on the liquid crystal region 17 from an oblique direction with respect to the substrate surface, one polarized component can be absorbed in the liquid crystal region 17 and the other polarized component can be absorbed in the liquid crystal region 18. Therefore, according to the liquid crystal display element 11, display with high contrast is possible.

In particular, when the liquid crystal display element 11 is a reflection type liquid crystal display element, not only direct light but also reflected light can be absorbed. Therefore, in this case, display with higher contrast is possible.

The above-mentioned effect becomes more remarkable as the length of the liquid crystal regions 17 and 18 parallel to the substrate surface becomes shorter. However, if the length is too short, the above effect cannot be obtained. This will be described with reference to FIG.

FIG. 4 is a graph showing the relationship between the size of the liquid crystal region and the absorbance of the liquid crystal display device according to the second embodiment of the present invention. In the figure, the horizontal axis indicates the length of the liquid crystal regions 17 and 18 parallel to the substrate surface, and the vertical axis indicates the absorbance.

The data shown in FIG. 4 was obtained under the following conditions. That is, the electrode 4 was a reflection electrode, and the cell gap was 20 μm. As for the alignment films 13 to 16, the facing alignment films 13 and 14 and the alignment films 15 and 16 are aligned in parallel, and if the alignment directions between the adjacent alignment films 13 and 15 and between the alignment films 14 and 16 are different by 90 °. Squeezed. In addition,
The shapes of the alignment films 13 to 16 were square. That is, the horizontal axis of the graph shown in FIG. 4 indicates the length of one side of the alignment films 13 to 16. The absorbance is obtained when light is incident on the liquid crystal layer 7 from the substrate surface of the liquid crystal display element 11 at an angle of 30 °.

As shown in FIG. 4, when the lengths of the liquid crystal regions 17 and 18 are shortened, the absorbance starts to increase when the length is about 20 μm, reaches saturation at about 14 μm, and becomes almost constant until about 5 μm. Have been obtained. However, 5
When it is less than μm, the absorbance is significantly reduced. This is considered to be because the alignment division between the liquid crystal regions 17 and 18 could not be performed.

The length of the decrease in the absorbance depends on the liquid crystal material used, but is usually about 2 to 7 μm. Therefore, the length of the liquid crystal regions 17 and 18 parallel to the substrate surface is preferably 2 μm or more.

The above-described effects are obtained by the liquid crystal regions 17 and 1.
The alignment directions of the liquid crystal material 20 are preferably different from each other by about 45 to 90 °, and more preferably by about 90 °. In this case, the light absorption efficiency can be further increased.

In the liquid crystal display element 11, the liquid crystal layer 7 may be formed using liquid crystal microcapsules.
In this case, as described in the first embodiment, anisotropic liquid crystal microcapsules are used, and the substrate surface is
Concave portions are provided in a pattern corresponding to the liquid crystal regions 17 and 18. Note that the recess is formed in a shape corresponding to one cross section of the liquid crystal microcapsule. As a result, the liquid crystal microcapsules having the anisotropic shape are fitted in the concave portions with a predetermined orientation. In this way, liquid crystal microcapsules having an anisotropic shape are arranged on the substrate 2 in a desired orientation, and liquid crystal regions 17 and 18 are formed.

Further, the liquid crystal regions 17 and 1 are placed on the substrate 2 in advance.
After the formation of the partition walls having a shape corresponding to that of the liquid crystal regions 8, the liquid crystal regions 17 and 1 are also formed by placing spherical liquid crystal microcapsules in the spaces surrounded by the partition walls and pressing and deforming them.
8 can be formed.

When the liquid crystal layer 7 is formed using liquid crystal microcapsules, the liquid crystal microcapsules 6-3 to 6-5 shown in FIGS. 2C to 2E can be used. In the second embodiment of the present invention, the liquid crystal layer 7 is configured, for example, as described below.

FIGS. 5A to 5C show front views of the liquid crystal layer of the liquid crystal display device according to the second embodiment of the present invention. The liquid crystal layers 7 shown in FIGS. 5A to 5C are each observed from a direction perpendicular to the substrate surface.

FIG. 5A shows that the liquid crystal layer 7 is
Are liquid crystal microcapsules 6-3 oriented in a radial form. FIG. 5B illustrates a liquid crystal microcapsule 6 in which a liquid crystal material 20 is radially aligned.
-3 and liquid crystal microcapsules 6-5 in which the liquid crystal material 20 is bipolar-oriented. FIG. 5C shows the liquid crystal layer 7 composed of liquid crystal microcapsules 6-5 in which the liquid crystal material 20 is bipolar-oriented.

According to the liquid crystal display element 11 using the liquid crystal layer 7 shown in FIGS. 5A to 5C, a display with a relatively high contrast is possible, but a bipolar liquid crystal microcapsule 6- is used. It is preferable to use 5. The radial liquid crystal microcapsules 6-3 exhibit the same absorptivity for incident light from any direction. In other words, in the radial liquid crystal microcapsules 6-3, the relationship between the optical axis and the orientation of the liquid crystal microcapsules 6-5 is optimized like the bipolar liquid crystal microcapsules 6-5, and the light absorption efficiency is improved. It cannot be improved.

On the other hand, in the bipolar liquid crystal microcapsules 6-5, more dichroic dyes are arranged in parallel to the substrate surface than in the radial liquid crystal microcapsules 6-3. Therefore, by configuring the liquid crystal layer 7 as shown in FIG. 5B, display with higher contrast is possible, and by configuring the liquid crystal layer 7 as shown in FIG. Display with contrast becomes possible. In FIGS. 5B and 5C, the bipolar liquid crystal microcapsules 6-5 can be replaced by axial liquid crystal microcapsules 6-4.

In each of FIGS. 5A to 5C, each liquid crystal microcapsule is formed in a plane parallel to the substrate surface.
It is arranged so as to be in contact with two liquid crystal microcapsules. Although it is possible to arrange each liquid crystal microcapsule so as to be in contact with four liquid crystal microcapsules in a plane parallel to the substrate surface, it is preferable to arrange as shown in FIGS. 5 (a) to 5 (c). . In this case, the amount of light transmitted through the gap between the liquid crystal microcapsules can be reduced.

In the above description, one liquid crystal microcapsule forms one liquid crystal region. However, one liquid crystal microcapsule may form one liquid crystal region. In addition, the transparent film of the liquid crystal microcapsule has the first
The same materials as described in the embodiment can be used. When the liquid crystal layer 7 is formed using liquid crystal microcapsules, it is not necessary to provide the alignment films 13 to 16 and the substrate 3 is not necessarily provided.

Further, the liquid crystal material 20 may be spirally arranged. When the liquid crystal material 20 is spirally arranged, a helical axis is controlled instead of controlling the alignment direction of the liquid crystal material 20. Thereby, the same effect as described above can be obtained.

Next, a third embodiment of the present invention will be described. The third embodiment of the present invention differs from the first embodiment only in that a liquid crystal microcapsule 6-3 is used instead of the liquid crystal microcapsules 6-1 or 6-2.

That is, in the liquid crystal display device according to the third embodiment of the present invention, at least one of the first and second liquid crystal microcapsule layers 8 and 9 is composed of the radial liquid crystal shown in FIG. It is composed of microcapsules 6-3.

FIGS. 6A and 6B schematically show an example of a liquid crystal layer of a liquid crystal display device according to a third embodiment of the present invention. FIG. 6A is a side view of the liquid crystal layer 7 observed from a direction parallel to the substrate surface, and FIG. 6B is a view of a part thereof observed from a direction perpendicular to the substrate surface. .

In the liquid crystal layer 7 shown in FIG. 6A, both of the liquid crystal microcapsule layers 8 and 9 are constituted by radial liquid crystal microcapsules 6-3. When the liquid crystal layer 7 is viewed from a direction perpendicular to the substrate surface, the liquid crystal microcapsules 6-3 adjacent between the liquid crystal microcapsule layers 8 and 9 are disposed.
Are not arranged so as to completely overlap each other, but are arranged so as to be shifted from each other as shown in FIG.

In the liquid crystal microcapsules 6-3, since the liquid crystal material is radially aligned, when the liquid crystal microcapsules 6-3 are stacked in parallel with the optical axis, the liquid crystal microcapsules 6-3 absorb the liquid crystal microcapsules 6-3. It is impossible for the other liquid crystal microcapsules 6-3 to absorb the polarization component that cannot be absorbed. This is because the alignment of the liquid crystal molecules existing on the optical axis of the incident light is equal in both liquid crystal microcapsules 6-3.

On the other hand, as shown in FIG. 6B, when the liquid crystal microcapsules 6-3 are displaced from the optical axis, the orientation of the liquid crystal molecules existing on the optical axis of the incident light is as follows.
The liquid crystal microcapsules 6-3 are different.
Therefore, it becomes possible to absorb the polarized light component that cannot be absorbed by one liquid crystal microcapsule 6-3 in the other liquid crystal microcapsule 6-3.

The case where both the liquid crystal microcapsule layers 8 and 9 are constituted by the radial liquid crystal microcapsules 6-3 has been described above.
One of 9 may be constituted by a radial type liquid crystal microcapsule 6-3, and the other may be constituted by a liquid crystal microcapsule exhibiting another orientation.

FIGS. 7A and 7B schematically show another example of the liquid crystal layer of the liquid crystal display device according to the third embodiment of the present invention. FIG. 7A is a side view of the liquid crystal layer 7 observed from a direction parallel to the substrate surface, and FIG. 7B is a view of a part of the liquid crystal layer 7 observed from a direction perpendicular to the substrate surface. .

In the liquid crystal layer 7 shown in FIG. 7A, the liquid crystal microcapsule layer 8 is composed of a bipolar liquid crystal microcapsule 6-5, and the liquid crystal microcapsule layer 9 is a radial liquid crystal microcapsule 6-. Consists of three. When the liquid crystal layer 7 is viewed from a direction perpendicular to the substrate surface, the liquid crystal microcapsules 6-5 and 6-3 adjacent between the liquid crystal microcapsule layers 8 and 9 are not arranged so as to completely overlap. , As shown in FIG. 6B.

When the liquid crystal layer 7 is configured as described above, the liquid crystal microcapsule layer 8 absorbs a polarized component in a predetermined polarization direction, and a part of the polarized component perpendicular thereto is absorbed in the liquid crystal microcapsule layer 9. Can be. Therefore, by configuring the liquid crystal layer 7 of the liquid crystal display element in such a manner, a display with high contrast can be performed.

In the foregoing, the use of the bipolar liquid crystal microcapsules 6-5 and the radial liquid crystal microcapsules 6-3 has been described. Instead of the bipolar liquid crystal microcapsules 6-5, FIG. ), (B),
Liquid crystal microcapsules 6-1, 6-2, 6-4 shown in (d) may be used. These liquid crystal microcapsules 6-
As described in the first embodiment, 1,6-2, 6-4, and 6-5 can be arranged such that the alignment direction or the helical axis of the liquid crystal material is parallel to the substrate surface. preferable.

According to the third embodiment of the present invention described above, the liquid crystal layer 7 can be formed relatively easily.
This is because, in the liquid crystal microcapsule layer formed by using the radial liquid crystal microcapsules 6-3, the liquid crystal material is isotropically aligned in the radial liquid crystal microcapsules 6-3. There is no need to do it.

Therefore, the liquid crystal microcapsule layers 8 and 9 shown in FIG. 6A can be formed by continuously laminating the radial liquid crystal microcapsules 6-3 and filling them closely. The liquid crystal layer 7 shown in FIG.
Is to form a liquid crystal microcapsule layer 8 by using a bipolar liquid crystal microcapsule 6-5, perform a stretching process, and then stack a radial liquid crystal microcapsule 6-3 to form a liquid crystal microcapsule layer 8. Can be obtained.

The liquid crystal microcapsules used in the liquid crystal display device according to the third embodiment of the present invention are made of the same materials as those described in the first and second embodiments. In particular, in order to form a radial liquid crystal microcapsule, it is necessary that the surface energy of the liquid crystal is larger than the surface energy of the capsule matrix material. Unless otherwise specified, members made of the same material are denoted by the same reference numerals.

[0109]

Embodiments of the present invention will be described below. (Example 1) The liquid crystal display element 1 shown in FIG. 1 was manufactured by the following method.

As a liquid crystal material, 1% by weight of a black dichroic dye S-435 manufactured by Mitsui Toatsu Co., Ltd., and Chiral added by Merck Co., Ltd. were added to Lixon-4033xx manufactured by Chisso Corporation having positive dielectric anisotropy. What added agent S-811 by 2 weight% was used. 80 parts by weight of this liquid crystal material, 14 parts by weight of methyl methacrylate as a monomer, 1 part by weight of divinylbenzene as a crosslinking agent, and 0.2 part by weight of benzoyl peroxide were mixed and dissolved. This mixed solution was passed through a hydrophilic porous glass tube having an average pore diameter of 1 μm into a 0.3% by weight aqueous solution of polyvinyl alcohol under conditions of a maximum pressure of 1.5 atm and a minimum pressure of 1.2 atm at a cycle of 10 Hz. Extrusion gave an emulsion.

This was stirred for 1 hour at a temperature of 85 ° C. and a stirring speed of 500 rpm to polymerize the above monomer component. After one hour, the product was purified by pouring the product together with pure water into a porous tube made of an ion exchange resin to obtain liquid crystal microcapsules 6. In addition, when this liquid crystal microcapsule 6 was observed with a microscope, it had a capsule tablet shape, and the average diameter in the major axis direction was 7 μm, and the average maximum diameter in the direction perpendicular to the major axis was 5 μm. I understood. The liquid crystal microcapsules were well dispersed in water, and no aggregation was observed even after standing for one day.

Next, a liquid crystal microcapsule coating liquid in which the liquid crystal microcapsules 6 were dispersed in a predetermined liquid was applied onto the glass substrate 2 having a reflective electrode 4 made of aluminum formed on one main surface. Further, the glass substrate 2
The liquid crystal layer 7 was obtained by heating and drying while applying ultrasonic waves to the.

Next, the glass substrate 3 having the transparent electrode 5 formed on one main surface was disposed such that the transparent electrode 5 was in contact with the liquid crystal layer 7. This was put in a bag made of polyamide, the inside of the bag was decompressed, and heated and adhered at 120 ° C., thereby producing a liquid crystal display element 1.

The liquid crystal display element 1 manufactured as described above
When observed with a microscope, no destruction of the liquid crystal microcapsules 6 was observed. The thickness of the liquid crystal layer 7 is 10 μm.
m, and it was confirmed that the liquid crystal layer 7 was composed of two liquid crystal microcapsule layers 8 and 9.

Further, in all the liquid crystal microcapsules 6, the helical axis of the liquid crystal material was substantially parallel to the substrate surface and perpendicular to the ultrasonic wave application direction. When an AC voltage of 50 Hz and 9 V was applied to the liquid crystal display element 1, the color changed from black when no voltage was applied to white. Further, the contrast ratio obtained from the reflection photometer was 6: 1.

Embodiment 2 FIG. 1 is obtained by the following method.
The liquid crystal display element 1 shown in FIG. As a liquid crystal material,
Chixso Lixon-403 having positive dielectric anisotropy
3xx, black dichroic dye S-43 manufactured by Mitsui Toatsu Co., Ltd.
5 and 1% by weight of Merck Chiral Agent S-811
What was added by weight% was used. 80 parts by weight of this liquid crystal material, 14 parts by weight of methyl methacrylate as a monomer,
1 part by weight of divinylbenzene as a crosslinking agent and 0.2 part by weight of benzoyl peroxide were mixed and dissolved. This mixed solution was passed through a hydrophilic porous glass tube having an average pore size of 1 μm,
In a 0.3% by weight aqueous solution of polyvinyl alcohol:
The mixture was extruded by applying a static pressure of 5 atm to obtain an emulsion.

This was stirred at a temperature of 85 ° C. and a stirring speed of 50 rpm for 1 hour to polymerize the above monomer component.
After one hour, the product was purified by pouring the product together with pure water into a porous tube made of an ion exchange resin to obtain liquid crystal microcapsules 6. When the liquid crystal microcapsules 6 were observed with a microscope, they were found to be spherical having an average particle diameter of 6 μm.

Next, the liquid crystal microcapsules 6 were applied on a base film made of polyvinyl alcohol, stretched while heating to 100 ° C., and cooled to room temperature. Thereby, the liquid crystal layer 7 was formed on the base film.

Next, a composite film composed of a base film and a liquid crystal layer 7 is formed on a glass substrate 2 having a reflective electrode 4 made of aluminum on one main surface so that the liquid crystal layer 7 is in contact with the reflective electrode 4. Was placed. After removing the base film by performing a water washing treatment, the glass substrate 3 having the transparent electrode 5 formed on one main surface was disposed such that the transparent electrode 5 was in contact with the liquid crystal layer 7. This was put in a bag made of polyamide, the inside of the bag was decompressed, and heated and adhered at 120 ° C., thereby producing a liquid crystal display element 1.

The liquid crystal display element 1 manufactured as described above
When observed with a microscope, no destruction of the liquid crystal microcapsules 6 was observed. The thickness of the liquid crystal layer 7 is 10 μm.
m, and it was confirmed that the liquid crystal layer 7 was composed of two liquid crystal microcapsule layers 8 and 9.

Further, in the liquid crystal microcapsules 6 in the liquid crystal microcapsule layer 8 and the liquid crystal microcapsules 6 in the liquid crystal microcapsule layer 9, the alignment direction of the liquid crystal molecules is 9
It was 0 ° different. In each of the liquid crystal microcapsule layers 8 and 9, the direction of the helical axis was substantially parallel to the substrate surface and also substantially parallel to the extending direction of the microcapsules.

When an AC voltage of 50 Hz and 9 V was applied to the liquid crystal display element 1, the color changed from black when no voltage was applied to white. Further, the contrast ratio obtained from the reflection photometer was 7: 1.

(Comparative Example 1) FIG.
The liquid crystal display element 1 shown in FIG. As a liquid crystal material,
Chixso Lixon-403 having positive dielectric anisotropy
3xx, black dichroic dye S-43 manufactured by Mitsui Toatsu Co., Ltd.
5 obtained by adding 1% by weight and 0.6% by weight. 80 parts by weight of this liquid crystal material, 14 parts by weight of methyl methacrylate as a monomer, 1 part by weight of divinylbenzene as a crosslinking agent, and 0.2 part by weight of benzoyl peroxide were mixed and dissolved. This mixed solution was poured from a hydrophilic porous glass tube having an average pore diameter of 1 μm into a 0.3% by weight aqueous solution of polyvinyl alcohol under conditions of a maximum pressure of 1.6 atm and a minimum pressure of 1.2 at a cycle of 1 Hz. Extrusion gave an emulsion.

This was stirred at a temperature of 85 ° C. and a stirring speed of 50 rpm for 1 hour to polymerize the above monomer component.
After one hour, the product was purified by pouring the product together with pure water into a porous tube made of an ion exchange resin to obtain liquid crystal microcapsules 6. When the liquid crystal microcapsules 6 were observed with a microscope, they were found to be spherical having an average particle diameter of 6 μm.

Next, a liquid crystal microcapsule coating liquid in which the liquid crystal microcapsules 6 are dispersed in a predetermined liquid is applied and dried on the glass substrate 2 having a reflective electrode 4 made of aluminum formed on one main surface. As a result, a liquid crystal layer 7 was obtained.

Further, the glass substrate 3 having the transparent electrode 5 formed on one main surface was disposed so that the transparent electrode 5 was in contact with the liquid crystal layer 7. This was put in a bag made of polyamide, the inside of the bag was decompressed, and heated and adhered at 120 ° C., thereby producing a liquid crystal display element 1.

The liquid crystal display element 1 manufactured as described above
Was observed with a microscope, and the thickness of the liquid crystal layer 7 was 10 μm.
The liquid crystal layer 7 has two liquid crystal microcapsule layers 8,
9 was confirmed.

In each of the liquid crystal microcapsule layers 8 and 9, the orientation direction of the liquid crystal molecules was substantially parallel to the substrate surface, but was random in a plane parallel to the substrate surface.

When an AC voltage of 50 Hz and 9 V was applied to the liquid crystal display element 1, the color changed from black when no voltage was applied to white. Further, the contrast ratio obtained from the reflection photometer was 5: 1.

(Embodiment 3) The liquid crystal display element 21 shown in FIG.
Was produced by the method shown below. FIG. 8 is a sectional view showing a liquid crystal display device according to an example of the present invention.

In manufacturing the liquid crystal display element 21, first, a fluorine-based liquid crystal mixture Lixon-503 manufactured by Chisso Corporation was used.
To 5XX, 1% by weight of a yellow anthraquinone dichroic dye represented by the above chemical formula (1) and 3% by weight of Chiral Additive CB-15 manufactured by Merck & Co. were added to prepare a yellow liquid crystal material. This yellow liquid crystal material 80
3 parts by weight of methyl methacrylate as a monomer, 11 parts by weight of octadecyl methacrylate, and 1 part by weight of divinylbenzene as a cross-linking agent were mixed and dissolved. This mixed solution was passed through a hydrophilic porous glass tube having an average pore size of 1 μm,
In a 0.3% by weight aqueous solution of polyvinyl alcohol:
The mixture was extruded by applying a static pressure of 5 atm to obtain an emulsion.

This was stirred for 1 hour at a temperature of 85 ° C. and a stirring speed of 50 rpm to polymerize the above monomer component.
After one hour, the product was purified by pouring the product with pure water into a porous tube made of an ion exchange resin to obtain a yellow liquid crystal microcapsule 6-6. When the liquid crystal microcapsules 6-6 were observed with a microscope, they were found to be spherical having an average particle size of 6 μm.

Next, the yellow liquid crystal microcapsules 6-6 were applied on a base film made of polyvinyl alcohol, stretched while heating to 100 ° C., and cooled to room temperature. As a result, a yellow liquid crystal layer 7-1 was formed on the base film.

Next, a magenta anthraquinone dichroic dye represented by the chemical formula (10) was used in place of the yellow dichroic dye represented by the chemical formula (1). Magenta liquid crystal microcapsules 6
-7 was produced. Further, using the magenta liquid crystal microcapsules 6-7, a magenta liquid crystal layer 7-2 was formed on the base film by the method described above.

Further, a cyan anthraquinone dichroic dye represented by the chemical formula (19) was used in place of the yellow dichroic dye represented by the chemical formula (1). Color liquid crystal microcapsules 6-8 were prepared. Further, using the cyan liquid crystal microcapsules 6-8, a cyan liquid crystal layer 7-3 was formed on the base film by the method described above.

Next, a transparent glass substrate 2 having a thickness of 0.7 mm was prepared.
Then, three lines of TFTs, gates, and signal lines 22 were formed for each pixel. Further, a polyimide film having a thickness of 2 μm was formed on the glass substrate 2 as a base film 23 of the reflective electrode 4, and was subjected to dimple processing by embossing. Further, after evaporating aluminum to a thickness of 100 nm on the base film 23, this is patterned to
The reflection electrode 4 was formed.

After the reflective electrode 4 was electrically connected to one source electrode of the three TFTs, an electrode column 25 having a height of 10 μm and a height of 22 μm were formed using a hydrophobic conductive paste.
Are formed by electrically connecting the source electrodes of the other two TFTs, respectively.

Next, a composite film of the base film and the yellow liquid crystal layer 7-1 was disposed such that the liquid crystal layer 7-1 was in contact with the reflective electrode 4. After removing the base film by performing a water washing treatment, the liquid crystal layer 7-1 is slit-coated with an aqueous solution of hydroxymethylcellulose, and the resulting solution is heated to a temperature lower than the glass transition temperature of the transparent film of the liquid crystal microcapsules 6-6. Drying was performed at a temperature of ℃ C to form a protective film 28. Incidentally, the aqueous solution of hydroxymethyl cellulose,
It has an affinity for the transparent film of the liquid crystal microcapsules 6-6 (contact angle is less than 5 °), and has no affinity for the electrode columns 25 and 26 (contact angle exceeds 50 °). After the protective film 28 was dried, the surface of the protective film 28 was made hydrophobic by annealing in an air atmosphere, and the adhesion between the liquid crystal microcapsules 6-6 and the substrate 2 was promoted.

Further, an ITO filler dispersion (a solution of polyester particles in toluene) was selectively applied onto the protective film 28 in a predetermined shape and dried at room temperature in a nitrogen atmosphere. The ITO filler dispersion is hydrophobic,
It shows an affinity for the protective film 28 and the electrode pillars 25 and 26. After drying the ITO filler, ultraviolet light having a center wavelength of 147 nm was irradiated to cure and impart conductivity, thereby forming the intermediate electrode 29. The intermediate electrode 29 formed as described above is electrically connected to the electrode column 25, and is electrically insulated from the electrode column 26.

Next, the cyan liquid crystal microcapsule layer 7-1 is formed on the intermediate electrode 29 by using the cyan liquid crystal microcapsules 6-7 in the same manner as the formation method of the yellow liquid crystal microcapsule layer 7-1. -2 formed. The protective film 3 is also formed on the liquid crystal microcapsule layer 7-2 by the method described above.
0 and the intermediate electrode 31 were formed. The intermediate electrode 31 is electrically connected to the electrode column 26.

Next, the magenta liquid crystal microcapsule layer 7-1 is formed on the intermediate electrode 31 using the magenta liquid crystal microcapsules 6-8 in the same manner as the formation method of the yellow liquid crystal microcapsule layer 7-1. -3 was formed. The protective film 32 was formed also on the liquid crystal microcapsule layer 7-3 by applying and drying an aqueous solution of hydroxymethyl cellulose.

Further, the transparent electrode 5 is formed on the protective film 32.
The liquid crystal display element 21 was produced by heating and pressing the glass substrate 3 on which was formed. When the liquid crystal display element 21 manufactured as described above was observed with a microscope,
No destruction of the transparent coating of the liquid crystal microcapsules 6-6 to 6-8 was observed. Further, all of the liquid crystal layers 7-1 to 7-3 are composed of the liquid crystal microcapsule layer 8-n and the liquid crystal microcapsule layer 9-n.
-n was laminated (n = 1 to 3).

In all of the liquid crystal layers 7-1 to 7-3,
It was confirmed that the direction of the helical axis was substantially parallel to the substrate surface, and the direction of the helical axis was substantially parallel between the liquid crystal microcapsule layers 8-n and 9-n. Further, since the liquid crystal display element 21 does not have an intermediate substrate, parallax and poor alignment of liquid crystal molecules, which normally occur when a laminated structure is formed, were not observed.

When a driver IC is mounted on the liquid crystal display element 21 by TAB and an AC voltage having a maximum signal amplitude of 5 V is applied independently between the electrodes, the color changes from black when no voltage is applied to white. The contrast ratio determined with a reflection photometer was 5: 1. In addition, color display with good color tone was possible.

(Comparative Example 2) FIG.
The liquid crystal display element 21 shown in FIG. The liquid crystal material is a fluorine-based liquid crystal mixture Lixon-503 manufactured by Chisso.
5XX was added with 1% by weight of a yellow anthraquinone dichroic dye represented by the above chemical formula (1). 80 parts by weight of this liquid crystal material, 14 parts by weight of a fluorine-based methacrylate as a monomer, and 0.2 parts by weight of benzoyl peroxide as a crosslinking agent were mixed and dissolved. This mixture was dropped into an aqueous solution containing 3 parts by weight of a surfactant in 300 parts by weight of pure water. The above aqueous solution is 6
It is kept at 5 ° C. and is stirred at a rotation speed of 1000 rpm.

While maintaining the temperature of the aqueous solution at 65 ° C.,
The above monomer component was polymerized by stirring at a stirring speed of 00 rpm for 1 hour. After one hour, the product was filtered through a 1 μm filter to remove fine products. The remaining product is washed three times with pure water and then dried,
Thus, a liquid crystal microcapsule 6-6 having a yellow color was obtained. In addition,
The liquid crystal microcapsules 6-6 are spherical bodies having an average particle size of 5 μm.

Next, 80 parts by weight of liquid crystal microcapsules 6-6 and 8 parts by weight of epoxy prepolymer (epicoat)
Was added dropwise to 200 parts by weight of a stirred 5% by weight aqueous gelatin solution to disperse the mixed liquid in the form of droplets. Stirring was continued at about 40 ° C. for 1 hour while gradually dropping a mixture of 50 parts by weight of pure water and 3 parts by weight of an amine-based curing agent into the aqueous gelatin solution.

After 1 hour, the product was filtered through a 1 μm filter to remove fine products. The remaining product was washed three times with pure water and dried to obtain yellow liquid crystal microcapsules 6-6. The liquid crystal microcapsules 6-6 are spherical bodies having an average particle diameter of 6 μm, and the transparent film is a composite film in which a fluorine-based methacrylate film and an epoxy resin are laminated.

Next, a yellow liquid crystal was used except that the magenta anthraquinone dichroic dye represented by the chemical formula (10) was used instead of the yellow dichroic dye represented by the chemical formula (1). A magenta liquid crystal microcapsule 6-7 was formed in the same manner as the microcapsule 6-6. Also, except that a cyan anthraquinone dichroic dye represented by the chemical formula (19) was used instead of the yellow dichroic dye represented by the chemical formula (1), a yellow liquid crystal microcapsule 6- A cyan liquid crystal microcapsule 6-8 was formed in the same manner as in the method of forming No. 6.

Using the liquid crystal microcapsules 6-6 to 6-8 prepared as described above, liquid crystal microcapsule coating solutions were prepared, and these liquid crystal microcapsule coating solutions were applied directly on the electrodes to form a liquid crystal layer. A liquid crystal display element 21 was produced in the same manner as in Example 3 except that 7-1 to 7-3 were formed.

The liquid crystal display element 2 manufactured as described above
No. 1 was observed with a microscope, and no destruction of the transparent coating of the liquid crystal microcapsules 6-6 to 6-8 was confirmed. Further, all of the liquid crystal layers 7-1 to 7-3 had a laminated structure in which a liquid crystal microcapsule layer 8-n and a liquid crystal microcapsule layer 9-n were laminated. In all of the liquid crystal layers 7-1 to 7-3, the alignment direction of the liquid crystal molecules was almost parallel to the substrate surface, but was random in a plane parallel to the substrate surface.

A driver IC is mounted on the liquid crystal display element 21 by TAB, and a maximum signal amplitude of 5 is applied between the electrodes.
When an AC voltage of V was applied independently, the color changed from black when no voltage was applied to white, and the contrast ratio determined by a reflection photometer was 3: 1. In particular, the color when no voltage was applied was light.

(Embodiment 4) FIG.
The liquid crystal display element 11 shown in FIG. Electrodes 4 and 5 were formed by depositing an ITO film with a thickness of 1000 Å on transparent glass substrates 2 and 3 having a thickness of 0.7 mm and patterning the ITO film into a predetermined pattern. Polyimide (PI) having a high pretilt angle was applied to a thickness of 50 nm on the surface of the glass substrate 2 on which the electrode 4 was formed, and alignment films 13 and 15 each having a 20 μm square having a different alignment direction were formed by a mask rubbing method. . The alignment films 13 and 15
Are arranged in a checkered pattern. Similarly, on the surface of the glass substrate 3 on which the electrodes 5 are formed, the alignment films 14 and
No. 16 was formed.

Next, these glass substrates 2 and 3 are sized so that the surfaces on which the alignment films 13 to 16 are formed face each other and the orientation directions of the facing alignment films are equal to each other.
A liquid crystal cell was fabricated by overlapping and sealing with an m spacer therebetween.

Further, a P-type liquid crystal material to which 2% by weight of a black dichroic dye was added was injected into the liquid crystal cell, and a liquid crystal display element 11 was produced by sealing. The liquid crystal display element 11 manufactured as described above is provided with 50 Hz, 10 Hz.
When an AC voltage of V was applied, the color changed from black when no voltage was applied to a colorless state. The contrast ratio obtained from the reflection photometer was 2: 1.

(Embodiment 5) As shown below, FIG.
The liquid crystal display element 1 shown in FIG. In this embodiment, the liquid crystal layer 7 is configured as shown in FIG.

In manufacturing the liquid crystal display element 1, first, 1000 mm thick transparent glass substrates 2 and 3
An ITO film was deposited to a thickness of Å and these I
The TO film is patterned into a predetermined pattern,
5 was formed.

Next, a liquid crystal microcapsule layer 8 was formed on the surface of the substrate 2 on which the electrodes 4 were formed, using a liquid crystal microcapsule 6-3 containing a liquid crystal material in a transparent film made of poly (tert-butyl methacrylate). did. The liquid crystal material in the liquid crystal microcapsules 6-3 contains a blue dichroic dye and is oriented radially. The average particle size of the liquid crystal microcapsules 6-3 was 7 μm. The liquid crystal microcapsule layer 8 was subjected to a stretching treatment while being heated to 50 ° C., to orient the liquid crystal material in a predetermined direction parallel to the substrate surface. That is, the liquid crystal microcapsule layer 8 composed of the bipolar liquid crystal microcapsules 6-5 was formed.

Next, on the liquid crystal microcapsule layer 8, the liquid crystal microcapsules 6 oriented in the radial direction are formed.
-3 was arranged to form a liquid crystal microcapsule layer 9. The liquid crystal microcapsule layer 9 was not stretched.

After forming the liquid crystal layer 7 as described above,
The glass substrate 3 was arranged so that the transparent electrode 5 was in contact with the liquid crystal layer 7. This was put in a bag made of polyamide, the inside of the bag was decompressed, and heated and adhered at 120 ° C., thereby producing a liquid crystal display element 1.

The thickness of the liquid crystal layer 7 of the liquid crystal display element 1 is 3
It was 0 μm. In addition, the liquid crystal display element 11 has 50H
When an AC voltage of z and 15 V was applied, the color changed from blue when no voltage was applied to a colorless state. Further, the contrast ratio obtained from the reflection photometer was 4: 1.

(Embodiment 6) The liquid crystal display element 31 shown in FIG.
Was produced by the method shown below. FIG. 9 is a sectional view showing a liquid crystal display device according to an example of the present invention.

In manufacturing the liquid crystal display element 31, first, a transparent glass substrate 2 having a thickness of 0.7 mm and a thickness of 0.7 mm were used.
The TFT, the gate, and the signal wiring 22 were formed on one main surface of each of the 5 mm transparent glass substrates 39 and 33.
A polyimide film having a thickness of 2 μm was formed on the glass substrate 2 as a base film 23 of the reflective electrode 4, and dimple processing was performed by embossing. Further, aluminum was deposited to a thickness of 100 nm on the base film 23 and then patterned to form the reflective electrode 4. The reflection electrode 4 was electrically connected to the source electrode of the TFT formed on the substrate 2.

On each of the glass substrates 39 and 33, an ITO film 34 having a thickness of 500 angstroms was formed in the same pattern as that of the reflective electrode 4 on the surface on which the TFT was formed. The ITO films 3 on the glass substrates 39 and 33
No. 4 was electrically connected to the source electrode of the TFT. Further, on the back surface of the glass substrate 39, 33 on which the ITO film 34 is formed, a 500 angstrom thick I
Each TO film 5 was formed.

Further, on one main surface of the transparent glass substrate 3 having a thickness of 0.7 mm, a 500 angstrom thick IT
An O film 5 was formed. Next, the orientation film 13 was formed on the surface of the glass substrate 2 on which the reflective electrode 4 was formed, the surface of the glass substrate 3 on which the ITO film 5 was formed, and both surfaces of the glass substrates 39 and 33 in the same manner as in Example 4. To 16 were respectively formed. In addition, each of the alignment films 13 to 16 is formed in a size of 50 μm square, and the substrates 39 and 33 are aligned with the alignment films 13 and 16.
15 were formed such that the alignment films 16 and 14 were located on the back surface. Further, with respect to the alignment direction of the alignment film 13,
The alignment films 15 and 15 were provided so that the alignment directions were vertical and the alignment direction of the alignment film 16 was parallel.

The glass substrates 2, 39 are aligned with the alignment films 13, 15.
Are opposite to the alignment films 14 and 16, respectively.
The first liquid crystal cell was formed by overlapping with a 0 μm spacer interposed therebetween. The second liquid crystal cell was formed by overlapping the glass substrates 3 and 33 in the same manner. These first and second liquid crystal cells are provided with alignment films 13 and 15 as alignment films 14 and 1.
6 is superimposed on each other so that 3
The liquid crystal cell of the layer was formed.

By injecting a P-type liquid crystal material containing magenta, cyan and yellow dichroic dyes into each layer of the three-layer liquid crystal cell thus manufactured, and sealing the liquid crystal cell, 31 was obtained. In the drawing, liquid crystal layers 7-1 to 7-3 indicate yellow, cyan, and magenta liquid crystal layers, respectively. For the dichroic dyes of magenta, cyan and yellow, materials having overlapping absorption spectra were selected. Further, in each of the liquid crystal layers 7-1 to 7-3, as shown in FIG. 9, the liquid crystal material has a 90 ° twist orientation.

A driver IC is mounted on the liquid crystal display element 31 by TAB, and a maximum signal amplitude of 5 is applied between the electrodes.
When an AC voltage of V was applied independently, the color changed from black when no voltage was applied to white, and the contrast ratio determined by a reflection densitometer was 3: 1.

(Embodiment 7) The liquid crystal display element 4 shown in FIG.
No. 1 was produced by the method shown below. In addition, FIG.
1 is a cross-sectional view illustrating a liquid crystal display device according to an example of the present invention.

In manufacturing the liquid crystal display element 41, first, three systems of TFTs, gates, and signal wirings 22 are formed on one main surface of a transparent glass substrate 2 having a thickness of 1.1 mm. Is a base film 23 of the reflective electrode 4
A polyimide film having a thickness of 2 μm was formed, and a dimple process was performed by embossing. After depositing aluminum to a thickness of 100 nm on the base film 23, the reflective electrode 4 was formed by patterning the aluminum. The reflection electrode 4 is formed of three TFTs formed on the substrate 2.
Was electrically connected to one of the source electrodes.

Next, the electrode columns 25 and 26 having a length of 10 μm were formed by being electrically connected to the respective source electrodes of the other two TFTs not connected to the reflection electrode 4.
Liquid crystal microcapsules 6-3 of yellow color on reflective electrode 4
Were laminated to form a liquid crystal layer 7-1. The liquid crystal material in the liquid crystal microcapsules 6-3 has a radial orientation. Further, the liquid crystal layer 7-1 is configured as shown in FIG.

Next, a transparent electrode 43 is formed in a predetermined pattern on both sides of a transparent resin film 42 having a thickness of 100 μm.
Holes were formed in units of pixels by punching at positions where the transparent electrodes 43 were not formed. After filling the hole with the conductive material 44, the transparent resin film 42 is placed on the liquid crystal layer 7-1 such that the electrode columns 25 are in contact with the transparent electrode 43 and the electrode columns 26 are in contact with the conductive material 44. Was placed.

Further, a magenta liquid crystal microcapsule 6-3 is laminated on the transparent resin film 42 to form a liquid crystal layer 7
-2 formed. The liquid crystal material in the liquid crystal microcapsules 6-3 has a radial orientation. The liquid crystal layer 7-2
Is configured as shown in FIG. 6A except that a conductive spacer 47 having a high light reflectance is disposed on the conductive material 44.

Next, the transparent glass substrate 3 having a thickness of 1.1 mm
A liquid crystal microcapsule 6-3 of cyan color was laminated thereon to form a liquid crystal layer 7-3. The liquid crystal layer 7 of the glass substrate 3
The ITO film 5 is formed by sputtering on the surface provided with -3. The liquid crystal microcapsules 6-3
The liquid crystal material inside has a radial alignment, and the liquid crystal layer 7-3
Is configured as shown in FIG.

On the liquid crystal layer 7-3, a transparent resin film 45 having a thickness of 100 μm and having transparent electrodes 46 formed in a predetermined pattern on both surfaces was disposed. Further, the glass substrate 3
Was disposed on the liquid crystal layer 7-2 such that the transparent resin film 45 was in contact with the liquid crystal layer 7-2 and the conductive spacer 47 was in contact with the transparent electrode 46. As described above,
A liquid crystal display element 41 was manufactured. The thickness of each of the liquid crystal layers 7-1 to 7-3 of the liquid crystal display element 41 was 15 μm.

A driver IC is mounted on the liquid crystal display element 41 by TAB, and a maximum signal amplitude of 5 is applied between the electrodes.
When an AC voltage of V was applied independently, the color changed from black when no voltage was applied to white, and the contrast ratio determined by a reflection densitometer was 5: 1.

Example 8 A liquid crystal display element 41 shown in FIG. 10 was produced in the same manner as in Example 7, except that the method of forming the liquid crystal layers 7-1 to 7-3 was different.

In the liquid crystal display element 41 according to this embodiment, the liquid crystal layers 7-1 to 7-3 have a structure in which two liquid crystal microcapsule layers shown in FIG. 5B are laminated. That is, it has a structure in which liquid crystal microcapsule layers in which radial liquid crystal microcapsules 6-3 and bipolar liquid crystal microcapsules 6-5 are alternately arranged are laminated.
Further, in the liquid crystal display element 41 according to the present embodiment, the liquid crystal microcapsules 6-3 adjacent in the direction perpendicular to the substrate surface,
6-5 are arranged as shown in FIG. 7 (b).

The liquid crystal layers 7-1 to 7-3 configured as described above
Was prepared as follows. That is, after a plurality of bipolar liquid crystal microcapsules stretched in a specific direction or subjected to an electric field application annealing to align the positions of the poles, are arranged on a substrate with a predetermined gap by using a transfer method, Radial liquid crystal microcapsules were filled in the gaps with transfer paper. The liquid crystal layer 7
-2 and 7-3 were also formed in the same manner as the liquid crystal layer 7-1.

A driver IC is mounted on the liquid crystal display element 41 by TAB, and a maximum signal amplitude of 5 is applied between the electrodes.
When an AC voltage of V was applied independently, the color changed from black when no voltage was applied to white, and the contrast ratio determined by a reflection densitometer was 5: 1.

(Embodiment 9) FIG.
The liquid crystal display element 21 shown in FIG. In this embodiment, the protective films 28, 30 and 32 were not provided.

In manufacturing the liquid crystal display element 21, first, Example 3 was placed on a transparent glass substrate 2 having a thickness of 1.1 mm.
In the same manner as described above, three systems of TFTs and gates, a signal wiring 22, a base film 23, and a reflection electrode 4 were formed for each pixel. Further, in the same manner as in the third embodiment,
After being electrically connected to one source electrode of the TFT of the system, the electrode pillar 25 having a height of 10 μm and the electrode pillar 26 having a height of 20 μm are electrically connected to the source electrodes of the other two TFTs, respectively. Formed. Dimples were formed on the surface of the base film 23 by using a photosensitive resin and performing exposure and development in a predetermined pattern.

Next, a yellow liquid crystal layer 7-1 is formed on the surface of the glass substrate 2 on which the reflective electrode 4 is formed by the following method.
Was formed. The liquid crystal layer 7-1 has a structure in which two liquid crystal microcapsule layers shown in FIG. That is, the bipolar liquid crystal microcapsules 6
-5, the alignment direction of the liquid crystal material between adjacent capsules is 90
It has a structure in which liquid crystal microcapsule layers arranged differently are stacked. The liquid crystal microcapsules 6-5 adjacent in the direction perpendicular to the substrate surface are arranged as shown in FIG. FIG. 11 is a front view showing the liquid crystal layer of the liquid crystal display element according to the example of the present invention from a direction perpendicular to the substrate surface.

The yellow liquid crystal layer 7-1 was formed as follows. That is, a plurality of bipolar liquid crystal microcapsules stretched in a specific direction or subjected to an electric field application annealing so that the positions of the poles are aligned are arranged on a substrate with a predetermined gap using a transfer method, and then the same. According to the method described above, the liquid crystal microcapsules in which the bipolar liquid crystal microcapsules are first arranged on the substrate and the direction of the helical axis are 90
The gap was filled at an angle of °.

Next, the liquid crystal layer 7 formed as described above
A transparent electrode 29 was formed on -1 by sputtering to form an ITO film with a thickness of 200 Å and patterning it into a predetermined pattern.
The transparent electrode 29 was electrically connected to the electrode column 25, and was electrically insulated from the electrode column 26.

The liquid crystal layer 7-2 for cyan, the transparent electrode 31, and the liquid crystal layer 7-3 for magenta were sequentially laminated on the transparent electrode 29 in the same manner as described above. The transparent electrode 3
1 was electrically connected to the electrode column 26.

Further, a 1.1 mm thick liquid crystal layer was formed on the liquid crystal layer 7-3.
The transparent electrode 5 is a transparent glass substrate.
-3, the liquid crystal display element 2
1 was produced.

A driver IC is mounted on the liquid crystal display element 21 by TAB, and a maximum signal amplitude of 5 is applied between the electrodes.
When an AC voltage of V was applied independently, the color changed from black when no voltage was applied to white, and the contrast ratio determined by a reflection densitometer was 5: 1.

Example 10 A liquid crystal display element 21 shown in FIG. 8 was manufactured by the following method. In the present embodiment, the protective films 28, 30, 32 and the electrode columns 25, 26 were not provided.

In manufacturing the liquid crystal display element 21, first, in the same manner as in the ninth embodiment, on the transparent glass substrate 2, three systems of TFTs and gates per pixel, the signal wiring 22,
Underlayer 23 and reflective electrode 4 were formed. Further, in the same manner as in Example 3, the reflective electrode 4 was electrically connected to one source electrode of three TFTs.

Next, a yellow liquid crystal layer 7-1 was formed by the following method. FIG. 12 shows a front view of a liquid crystal microcapsule layer of a liquid crystal display device according to an example of the present invention. As shown in this figure, the yellow liquid crystal microcapsules 6 are filled in the partition walls 50 made of photosensitive polyimide. The partition 50 forms a rectangular liquid crystal region,
A checkerboard pattern is formed using the three liquid crystal regions juxtaposed in the short axis direction as one unit.

As shown in FIG. 12, the yellow liquid crystal microcapsules 6 filled in the partition walls 50 are deformed in accordance with the shape of the partition walls, and the liquid crystal material 20 contained in the capsule is deformed.
Are oriented in the major axis direction of the liquid crystal region.

By providing the liquid crystal microcapsule layer thus configured on the surface of the substrate 2 on which the reflective electrode 4 is formed, and further laminating a separately formed liquid crystal microcapsule layer on this liquid crystal microcapsule layer, Thickness 10μ
m of the liquid crystal layer 7-1 was formed. The adjacent liquid crystal regions between the liquid crystal microcapsule layers were arranged so that the direction of the long axis was vertical. In addition, a part of the partition wall 50 was made conductive, and conduction was achieved on the liquid crystal layer 7-1 from the source electrodes of the two systems of TFTs not electrically connected to the reflective electrode 4.

Next, on the liquid crystal layer 7-1, a transparent resin in which ITO fine particles were dispersed was applied, and a transparent electrode 29 was formed in a pattern corresponding to the reflective electrode 4. The transparent electrode 29 was electrically connected to one source electrode of the two TFTs via the conductive portion of the partition 50, and was electrically insulated from the source electrode of the other TFT.

Next, a cyan liquid crystal layer 7-2, a transparent electrode 31, and a magenta liquid crystal layer 7-3 were sequentially laminated on the transparent electrode 29 by the above-described method. The transparent electrode 31
Is electrically connected to the source electrode of the other TFT via a conductive portion provided on the partition wall 50 of the cyan liquid crystal layer 7-2.

Further, a 1.1 mm thick liquid crystal layer 7-3 was formed on the liquid crystal layer 7-3.
The transparent electrode 5 is a transparent glass substrate.
-3, the liquid crystal display element 2
1 was produced.

A driver IC is mounted on the liquid crystal display element 21 by TAB, and a maximum signal amplitude of 5 is applied between the electrodes.
When an AC voltage of V was applied independently, the color changed from black when no voltage was applied to white, and the contrast ratio determined by a reflection densitometer was 5: 1.

[0198]

As described above, according to the liquid crystal display device of the present invention, the liquid crystal layer is formed by arranging the liquid crystal microcapsules such that the helical axis is oriented in the first direction.
And a second liquid crystal microcapsule layer in which the liquid crystal microcapsules are arranged so that the helical axis is oriented in the second direction. The polarization component in a predetermined polarization direction can be absorbed by the capsule layer, and the polarization component transmitted through the first liquid crystal microcapsule layer can be absorbed by the second liquid crystal microcapsule layer. Can be absorbed, and display with high contrast can be performed. Further, in this case, the first and second liquid crystal microcapsule layers are laminated so that the helical axes of the liquid crystal material are substantially parallel, so that the liquid crystal material can be easily manufactured with high accuracy.

According to the liquid crystal display device of the present invention, the liquid crystal layer is formed by regularly juxtaposing the first and second liquid crystal regions having different alignment directions of the liquid crystal material. A polarized component in a predetermined polarization direction can be absorbed by the liquid crystal region, and a part of the polarized component transmitted through the first liquid crystal region can be absorbed by the second liquid crystal region, so that display with high contrast can be performed. .

Further, according to the liquid crystal display device of the present invention,
The liquid crystal layer has a laminated structure in which liquid crystal microcapsule layers are laminated, and any one of the liquid crystal materials is composed of liquid crystal microcapsules exhibiting a radial alignment, so that a predetermined liquid crystal microcapsule layer is transmitted through one of the liquid crystal microcapsule layers. Part of the polarization component in the polarization direction can be absorbed by the liquid crystal microcapsule layer composed of the radial liquid crystal microcapsules, so that a display with high contrast can be performed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a liquid crystal display device according to a first embodiment of the present invention.

FIGS. 2A to 2E are cross-sectional views each showing a liquid crystal microcapsule used in the liquid crystal display device according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a liquid crystal display device according to a second embodiment of the present invention.

FIG. 4 is a graph showing the relationship between the size of a liquid crystal region and the absorbance of a liquid crystal display device according to a second embodiment of the present invention.

FIGS. 5A to 5C are front views each showing a liquid crystal layer of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 6A is a side view schematically showing an example of a liquid crystal layer of a liquid crystal display device according to a third embodiment of the present invention, and FIG.
Is a front view showing a part thereof.

FIG. 7A is a side view schematically showing another example of the liquid crystal layer of the liquid crystal display element according to the third embodiment of the present invention,
(B) is a front view showing a part thereof.

FIG. 8 is a sectional view showing a liquid crystal display device according to an example of the present invention.

FIG. 9 is a sectional view showing a liquid crystal display device according to an example of the present invention.

FIG. 10 is a sectional view showing a liquid crystal display device according to an example of the present invention.

FIG. 11 is a front view showing a liquid crystal layer of the liquid crystal display device according to the example of the present invention.

FIG. 12 is a front view showing a liquid crystal microcapsule layer of the liquid crystal display device according to the embodiment of the present invention.

[Explanation of symbols]

 1,11,21,31,41 ... Liquid crystal display element 2,3,33,39 ... Substrate 4,5,29,31,34,43,46 ... Electrode 6,6-n ... Liquid crystal microcapsule 7,7- n: Liquid crystal layer 8, 9, 8-n, 9-n: Liquid crystal microcapsule layer 10, 20: Liquid crystal material 12: Liquid crystal molecule 13-16: Alignment film 17, 18, Liquid crystal region 19: Dichroic dye 22: TFT, gate, and signal wiring 23... Underlayer 25 and 26... Electrode pillars 28 and 32. Protective film 37... Transparent film 38... Spiral axis 44.

Continuing on the front page (72) Inventor Kazuyuki Sunohara 33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Production Technology Laboratory Co., Ltd.

Claims (3)

[Claims] 1. A substrate having electrodes formed on at least one main surface thereof; a liquid crystal layer formed on a surface of the substrate having electrodes formed thereon, the liquid crystal layer having a liquid crystal microcapsule containing a liquid crystal material in a transparent film, and the liquid crystal A counter electrode provided on a layer, wherein the liquid crystal material has a helical structure in the liquid crystal microcapsule, and the liquid crystal layer has a liquid crystal microcapsule so that the helical axis is oriented in a first direction. It has a laminated structure in which a first liquid crystal microcapsule layer arranged and a second liquid crystal microcapsule layer arranged with the liquid crystal microcapsules are arranged such that the helical axis is oriented in the second direction. The liquid crystal display device, wherein the first and second directions are substantially parallel. 2. The liquid crystal display device according to claim 1, wherein the first and second directions are substantially parallel to a substrate surface. 3. The liquid crystal display device according to claim 1, wherein the liquid crystal microcapsules have an anisotropic shape.