JPH05273576A - Light scattering type liquid crystal two-layered panel - Google Patents

Abstract

PURPOSE:To provide a panel which is extremely higher in contrast than the contrast of the conventional light scattering type liquid crystal device in the case of constitution as a direct viewing type and can make direct viewing type black and white display, direct viewing type color display and direct viewing type full-color display. CONSTITUTION:This light scattering type liquid crystal two-layered panel consists of the light scattering type liquid crystal display panel constituted by having a light control layer 5 held. between two sheets of substrates 1 having transparent electrode layers and incorporating a liquid crystal material 3 and a transparent solid material in the light control layer 5 and the twisted nematic liquid crystal display panel having two sheets of polarizing plates 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device capable of achieving bright and high contrast, and by electrically switching the display with high-speed response, a decorative display plate such as a notice plate, It is used as various display devices such as clocks, calculators, and computer terminals that require a bright screen.

[0002]

2. Description of the Related Art Conventionally, liquid crystal display elements are of TN (twisted nematic) type using nematic liquid crystal,
The STN (Super Twisted Nematic) type has been put into practical use. Also, a liquid crystal device using a ferroelectric liquid crystal has been proposed.

Since these require a polarizing plate, there is a limit in brightening the surface.

On the other hand, as a method for producing a large-sized and inexpensive liquid crystal device which is bright and has good contrast without requiring a polarizing plate or alignment treatment, liquid crystal droplets are dispersed in a polymer by encapsulating liquid crystal, and the polymer is A method of forming a film is known. Japanese Patent Publication No. 58-501631,
U.S. Pat. No. 4,435,047 proposes gelatin, gum arabic, polyvinyl alcohol, and the like as encapsulating substances. In addition to these, for example, in Japanese Patent Publication No. 61-502128, liquid crystal is disclosed. Dispersed in an epoxy resin, JP-A-61-305528 discloses that the phase separation between a liquid crystal and a photo-cured product is fixed by light exposure, and JP-A-62-2231 discloses a special one. In which a liquid crystal is dispersed in an ultraviolet curable polymer
JP-A-144321 discloses a method of forming a film by mixing polyester, liquid crystal and a solvent.

However, Japanese Patent Laid-Open No. 58-501631
Japanese Patent Publication No. 6-502128 and Japanese Patent Application Laid-Open No. 6-502128.
The liquid crystal device obtained by the technique disclosed in Japanese Patent Laid-Open No. 1-2231 is driven by a high voltage of 25 V or more, and in most cases 50 V to 200 V to obtain sufficient transparency. And JP-A-1-6
The liquid crystal device disclosed in Japanese Patent No. 2615 has a contrast ratio of 10, which is the best, and often 8
The following were not provided with the characteristics required for practical use of liquid crystal devices.

Furthermore, in order to enable the low-voltage drivability, high contrast, and time-division drivability, which are the important characteristics required for the practical use of the liquid crystal device as described above, Japanese Patent Laid-Open No. 1-11
Japanese Patent Publication No. 98725 discloses a liquid crystal device having a structure in which a liquid crystal material forms a continuous layer and a polymer substance is distributed in a three-dimensional network in the continuous layer.

[0007]

However, when the light-scattering type liquid crystal device as described above is used as a display panel, since the light-scattering is used, a black color is installed behind the panel even when no voltage is applied. Alternatively, it has a major drawback that other colors are not blocked and a thin image appears even in a clouded portion. For this reason, it has been difficult to perform direct-viewing type display, and particularly full-color display has been impossible.

The problem to be solved by the present invention is that the black or other colors installed at the rear of the panel do not appear thinly in the cloudy part even when no voltage is applied, and direct-viewing type light scattering is possible. Type liquid crystal device.

[0009]

The present inventors have established a new liquid crystal device that solves the above problems by combining the above-mentioned light scattering type liquid crystal display technology with the conventionally known liquid crystal display technology. It was

That is, in order to solve the above-mentioned problems, the present invention provides a first light-scattering liquid crystal two-layer panel (1) a substrate sandwiched between two transparent substrates having transparent electrode layers. A light having a light layer, the light control layer comprising a light-scattering liquid crystal display panel containing a liquid crystal material and a transparent solid substance, and a twisted nematic liquid crystal display panel having two polarizing plates. A scattering type liquid crystal two-layer panel is provided.

Further, as a second light-scattering type liquid crystal two-layer panel of the present invention, (2) a twisted nematic liquid crystal display panel
Provided is a light-scattering liquid crystal two-layer panel according to (1), characterized in that at least one of the polarizing plates is a color polarizing plate.

Further, as a third light-scattering type liquid crystal two-layer panel of the present invention, (3) a twisted nematic liquid crystal display panel is R
A light-scattering liquid crystal two-layer panel having a GB color filter layer is provided.

The light-scattering liquid crystal two-layer panel of the present invention is generally used as a twisted nematic liquid crystal display panel.
Twisted nematic liquid crystal display that uses a color polarizing plate or color filter that can display clear black and white when using a twisted nematic liquid crystal display element that can be used alone for black and white display When an element is used, clear color display is possible.

Further, such a light-scattering liquid crystal 2 of the present invention is used.
In the layered panel, the twisted nematic liquid crystal display panel has a twist angle of 70 to 110 °, or 1
Those in the range of 80 to 270 ° can be used without particular limitation.

Further, in the light-scattering liquid crystal two-layer panel of the present invention, an active element or a non-linear element can be provided for each pixel of the light-scattering liquid crystal display panel and the twisted nematic liquid crystal display panel. The light-scattering liquid crystal double-layer panel of is subject to conditions such as black-and-white, color or full-color display, twist angle in twisted nematic liquid crystal display panel and presence or absence of active element in light scattering liquid crystal panel or twisted nematic liquid crystal display panel. Various types can be obtained by selecting and combining.

An example of the combination will be described below. As an example of the liquid crystal two-layer panel of the present invention, the structure of a monochrome type liquid crystal two-layer panel is shown in FIGS. 1 and 2.

1 and 2, 1 is a substrate, 2 is a transparent electrode, 3 is a liquid crystal material, 4 is a polarizing plate, 5 is a light control layer, and 6 is a sealant. And 7 is a reflector.

In FIG. 1, panel A is a light-scattering type liquid crystal display panel, panel B is a twisted nematic liquid crystal display panel, and two polarizing plates 4 are arranged orthogonal to each other.

In FIG. 1 (a), when no voltage is applied to the panel A, the light incident from the front is scattered by the light control layer 5 of the panel A and becomes opaque, but the light traveling straight is reflected in the panel B.
Incident on. At this time, the panel B is set so that no voltage is applied, and the incident light is transmitted by being twisted by 90 ° by the liquid crystal material 3 of the panel B and is reflected by the white reflecting plate 7 of the back, so that it is white when viewed from the front. Become.

In FIG. 1B, when the voltage is applied to the panel A, the light incident from the front is directly transmitted and is incident on the panel B. At this time, the panel B is set so that a voltage is applied, and the incident light is blocked by the two polarizing plates 4 which are orthogonal to each other, and becomes black when viewed from the front.

Although FIG. 1 shows an example of a reflective liquid crystal two-layer panel, it is also used as a transmissive liquid crystal two-layer panel by installing a backlight behind the panel B without using the reflector 7. be able to.

In FIG. 2, panel A is a light-scattering type liquid crystal display panel, panel B is a twisted nematic liquid crystal display panel, and two polarizing plates 4 are arranged in parallel with each other.

In FIG. 2 (a), when no voltage is applied to the panel A, the light incident from the front is scattered by the light control layer 5 of the panel A and becomes opaque, but the light traveling straight is reflected in the panel B.
Incident on. At this time, the panel B is set so that a voltage is applied, the incident light is transmitted as it is, is reflected by the white reflector 7 of the back, and becomes white when viewed from the front.

In FIG. 2B, when a voltage is applied to the panel A, the light incident from the front is directly transmitted and is incident on the panel B. At this time, the panel B is set so that no voltage is applied, and the incident light is twisted by 90 ° by the liquid crystal material 3 of the panel B and blocked by the two parallel polarizing plates 4 to become black when viewed from the front. .

FIG. 2 shows an example of a reflective liquid crystal two-layer panel, but by using a backlight behind the panel B without using the reflector 7, it can also be used as a transmissive liquid crystal two-layer panel. be able to.

As an example of the liquid crystal two-layer panel of the present invention, the structure of a color type liquid crystal two-layer panel is shown in FIGS.
3 and 4, 1 is a substrate, 2 is a transparent electrode, 3 is a liquid crystal material, 4 is a polarizing plate, 5 is a light control layer, 6 is a sealant, Reference numeral 7 is a reflector, and 8 is a color polarizing plate.

In FIG. 3, panel A is a light-scattering type liquid crystal display panel, panel B is a twisted nematic liquid crystal display panel, and two polarizing plates 4 and 8 are arranged orthogonal to each other.

In FIG. 3 (a), when no voltage is applied to the panel A, the light incident from the front is scattered by the light control layer 5 of the panel A and becomes opaque, but the light traveling straight is reflected in the panel B.
Incident on. At this time, the panel B is set so that no voltage is applied, and the incident light is transmitted by being twisted by 90 ° by the liquid crystal material 3 of the panel B and reflected by the white reflector 7 on the back, and is white when viewed from the front. Becomes

In FIG. 3B, when a voltage is applied to the panel A, the light incident from the front is directly transmitted and is incident on the panel B. At this time, the panel B is set so that a voltage is applied, and the incident light is blocked by the two polarizing plates 4 and 8 which are orthogonal to each other, and a color display is obtained when viewed from the front.

FIG. 3 shows an example of a reflection type liquid crystal two-layer panel, but by using a backlight behind the panel B without using the reflection plate 7, it can also be used as a transmission type liquid crystal two-layer panel. be able to.

In FIG. 4, panel A is a light scattering type liquid crystal display panel, panel B is a twisted nematic liquid crystal display panel, and two polarizing plates are arranged in parallel with each other.

In FIG. 4A, when no voltage is applied to the panel A, the light incident from the front is scattered by the light control layer 5 of the panel A and becomes opaque, but the light traveling straight is reflected in the panel B.
Incident on. At this time, the panel B is set so that a voltage is applied, the incident light is transmitted as it is, is reflected by the white reflector 7 of the back, and becomes white when viewed from the front.

In FIG. 4B, when the voltage is applied to the light control layer 5 of the panel A, the light incident from the front is transmitted as it is and is incident on the panel B. At this time, the panel B is set so that no voltage is applied, and the incident light is twisted by 90 ° by the liquid crystal material 3 of the panel B and blocked by the two parallel polarizing plates 4 and 8, and seen from the front. Display in color.

FIG. 4 shows an example of a reflection type liquid crystal two-layer panel, but it is also used as a transmission type liquid crystal two-layer panel by installing a backlight behind the panel B without using the reflector 7. be able to.

As an example of the liquid crystal two-layer panel of the present invention, the structure of a full-color type liquid crystal two-layer panel is shown in FIGS. 5 and 6, 1 is a substrate, 2 is a transparent electrode, 3 is a liquid crystal material, 4 is a polarizing plate, 5 is a light control layer, 6 is a sealant, 7 is a reflector, 9
Is an RGB color filter.

In FIG. 5, panel A is a light-scattering type liquid crystal display panel, panel B is a twisted nematic liquid crystal display panel, and two polarizing plates 4 are arranged in parallel with each other.

In FIG. 5 (a), when no voltage is applied to the panel A, the light incident from the front is scattered by the light control layer 5 of the panel A and becomes opaque, but the light traveling straight is reflected in the panel B.
Incident on. At this time, the panel B is set so that no voltage is applied, and the incident light is twisted by 90 ° by the liquid crystal material 3 of the panel B and blocked by the two parallel polarizing plates 4, and the RGB of the panel B is viewed from the front. The color of the color filter 9 cannot be seen.

In FIG. 5B, when the voltage is applied to the panel A, the light incident from the front is directly transmitted and is incident on the panel B. At this time, the panel B is set so that a voltage is applied, and the incident light is transmitted as it is,
By passing through the RGB color filter 9 of the panel B, the color of the RGB color filter 9 can be seen.

FIG. 5 shows an example of a reflective liquid crystal two-layer panel, but it is also used as a transmissive liquid crystal two-layer panel by installing a backlight behind the panel B without using the reflector 7. be able to.

In FIG. 6, panel A is a light-scattering type liquid crystal display panel, panel B is a twisted nematic liquid crystal display panel, and two polarizing plates are arranged perpendicular to each other.

In FIG. 6A, when no voltage is applied to the panel A, the light incident from the front is scattered by the light control layer 5 of the panel A and becomes white turbid, but the light traveling straight is reflected in the panel B.
Incident on. At this time, the panel B is set so that a voltage is applied, and the incident light is blocked by the two polarizing plates 4 which are orthogonal to each other, and the color of the RGB color filter 9 of the panel B cannot be seen from the front. .

In FIG. 6B, when the voltage is applied to the light control layer 5 of the panel A, the light incident from the front is directly transmitted and is incident on the panel B. At this time, the panel B is set so that no voltage is applied, and the incident light is twisted by 90 ° and transmitted by the liquid crystal of the panel B, and the
RG by passing through the GB color filter 9
The color of the B color filter 9 is visible.

FIG. 6 shows an example of a reflection type liquid crystal two-layer panel, but it is also used as a transmission type liquid crystal two-layer panel by installing a backlight behind the panel B without using the reflector 7. be able to.

As an example of the liquid crystal two-layer panel of the present invention, the structure of a monochrome type liquid crystal two-layer panel is shown in FIGS. Figure 7
In FIG. 8, 1 is a substrate, 2 is a transparent electrode, 3
Is a liquid crystal material, 4 is a polarizing plate, 5 is a light control layer, 6 is a sealant, 7 is a reflector, and 10 is a phase plate.

In FIG. 7, panel A is a light-scattering type liquid crystal display panel, panel B is a twisted nematic liquid crystal display panel having a twist angle of 240 °,
The two polarizing plates are arranged in the yellow mode.

In FIG. 7A, when no voltage is applied to the panel A, the light incident from the front is scattered by the light control layer 5 of the panel A and becomes opaque, but the light traveling straight is incident on the panel B. At this time, the panel B is set so that no voltage is applied, and the incident light is transmitted through the phase plate 10 of the panel B, twisted by 240 ° by the liquid crystal material 3 and transmitted, and reflected by the white reflector 7 of the back. Then, it becomes white when viewed from the front.

In FIG. 7B, when a voltage is applied to the panel A, the light incident from the front is directly transmitted and is incident on the panel B. At this time, the panel B is set so that a voltage is applied, and the incident light is blocked by the phase plate 10 and the two polarizing plates 4, and becomes black when viewed from the front.

FIG. 7 shows an example of a reflective liquid crystal two-layer panel, but by using a backlight behind the panel B without using the reflector 7, it can also be used as a transmissive liquid crystal two-layer panel. be able to.

In FIG. 8, panel A is a light scattering type liquid crystal display panel, panel B is a twisted nematic liquid crystal display panel having a twist angle of 240 °,
The two polarizing plates are arranged in the blue mode.

In FIG. 8A, when no voltage is applied to the panel A, the light incident from the front is scattered by the light control layer 5 of the panel A and becomes opaque, but the light traveling straight is reflected in the panel B.
Incident on. At this time, the panel B is set so that a voltage is applied, the incident light is transmitted as it is, is reflected by the white reflector 7 of the back, and becomes white when viewed from the front.

In FIG. 8B, when the voltage is applied to the panel A, the light incident from the front is directly transmitted and is incident on the panel B. At this time, the panel B is set so that no voltage is applied, and the incident light is twisted 240 ° by the liquid crystal material 3 of the panel B, blocked by the phase plate 10 and the polarizing plate 4, and turned black when viewed from the front.

FIG. 8 shows an example of a reflective liquid crystal two-layer panel, but it is also used as a transmissive liquid crystal two-layer panel by installing a backlight behind the panel B without using the reflector 7. be able to.

The light-scattering type liquid crystal two-layer panel of FIGS. 1 to 8 according to the present invention having such a structure has excellent contrast characteristics, but in the case of obtaining an excellent gradation display, , Can be easily obtained by simply changing the combination of the two panels that can be used in the present invention without changing the drive circuit.

The substrate used in the present invention may be a rigid material such as glass, or may be a flexible material such as a plastic film. The two substrates are opposed to each other and are separated by an appropriate distance, and the whole or a part of the light control layer composed of a liquid crystal layer and a layer having a transparent solid substance sandwiched between the two substrates is exposed to the outside. It must be visible from

However, in the case of a flexible material such as a plastic film, it can be fixed to a rigid material and then used in the light-scattering liquid crystal two-layer panel of the present invention.

In addition, a spacer for holding a space can be usually interposed between the two substrates, as in a known liquid crystal device. As the spacer, for example, those for various liquid crystal cells such as mylar, alumina, rod-type glass fiber, glass beads, and polymer beads can be used.

The liquid crystal material 3 does not need to be a single liquid crystal compound, but may be a mixture of two or more kinds of liquid crystal compounds or substances other than the liquid crystal compounds, and usually, Any material can be recognized as a liquid crystal material in the technical field, and one having a positive dielectric anisotropy is preferable. The liquid crystal used is preferably a nematic liquid crystal, a smectic liquid crystal or a cholesteric liquid crystal, and a nematic liquid crystal is particularly preferable. In order to improve the performance, a cholesteric liquid crystal, a chiral nematic liquid crystal, a chiral smectic liquid crystal or the like, or a chiral compound may be appropriately contained.

The liquid crystal material 3 used in the present invention is preferably a blended composition comprising one or more compounds selected from the compound group shown below, and the characteristics of the liquid crystal material, that is, isotropic liquid and liquid crystal Used for the purpose of improving the phase transition temperature, melting point, viscosity, Δn (refractive index anisotropy), Δε (dielectric anisotropy), solubility with a polymerizable composition, etc. be able to.

Examples of the liquid crystal material include 4-substituted benzoic acid 4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4'-substituted biphenyl ester, 4- (4-substituted cyclohexanecarbonyloxy)
Benzoic acid 4'-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid 4'-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid 4'-substituted cyclohexyl ester, 4-substituted 4'-substituted Biphenyl, 4-substituted phenyl-4'-substituted cyclohexane,
4-substituted 4 ″ -substituted terphenyl, 4-substituted biphenyl 4′-substituted cyclohexane, 2- (4-substituted phenyl)
-5-substituted pyrimidine etc. can be mentioned.

The light control layer 5 of the light-scattering type liquid crystal display panel used in the present invention may be, for example, one in which a liquid crystal is encapsulated by polyvinyl alcohol or the like as described in JP-A-58-501631, and, for example, , Tokushusho Sho 61
A liquid crystal droplet may be dispersed in an epoxy resin as described in JP-A-502128.
The liquid crystal droplets may be dispersed in a photo-cured product by phase separation by light exposure as described in JP-A-305528, and for example, a liquid crystal material as described in JP-A-1-198725 forms a continuous layer. In this continuous layer, the polymer material may have a structure in which it is distributed in a three-dimensional network.

For example, the ratio of the liquid crystal material 3 in the light control layer having a structure in which the liquid crystal material 3 forms a continuous layer and the polymer substance is distributed in a three-dimensional network in the continuous layer is 60% by weight or more. Is more preferable, and more specifically, the range of 60 to 95% by weight is preferable, and the range of 70 to 90% by weight is particularly preferable.

As the transparent solid substance giving a three-dimensional network structure, a thermosetting resin or an ultraviolet curable resin obtained by polymerizing a polymer-forming monomer or oligomer is preferable.

As the polymer-forming monomer, for example,
Styrene, chlorostyrene, α-methylstyrene, divinylbenzene: as a substituent, methyl, ethyl, propyl, butyl, amyl, 2-ethylhexyl, octyl,
Nonyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl, phenoxyethyl, allyl, methallyl, glycidyl, 2-hydroxyethyl, 2-hydroxypropyl,
Acrylate, methacrylate or fumarate having a group such as 3-chloro-2-hydroxypropyl, dimethylaminoethyl, diethylaminoethyl and the like; ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, tetramethylene glycol, Hexamethylene glycol, neopentyl glycol, trimethylolpropane, glycerin and pentaerythritol mono (meth) acrylate or poly (meth) acrylate; vinyl acetate, vinyl butyrate or vinyl benzoate, acrylonitrile, cetyl vinyl ether, limonene, cyclohexene, diallyl. Phthalate, diallyl isophthalate, 2-, 3- or 4-vinyl pyridine, acrylic acid, methacrylic acid, acetic acid Rylamide, methacrylamide, N-hydroxymethyl acrylamide or N-hydroxyethyl methacrylamide and their alkyl ether compounds; Di (meta of diol obtained by adding 2 mol or more of ethylene oxide or propylene oxide to 1 mol of neopentyl glycol. ) Acrylate;
Di- or tri (meth) acrylate of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane; obtained by adding 2 mol or more of ethylene oxide or propylene oxide to 1 mol of bisphenol A. Di (meth) acrylate of diol; Reaction product of 1 mol of 2-hydroxyethyl (meth) acrylate and 1 mol of phenyl isocyanate or n-butyl isocyanate;
Examples of the poly (meth) acrylate of dipentaerythritol include trimethylolpropane triacrylate, tricyclodecane dimethylol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate. Acrylate and tris- (acryloxyethyl) isocyanurate are particularly preferred.

Examples of the polymer-forming oligomer include caprolactone-modified hydroxypivalic acid ester neopentyl glycol diacrylate.

In order to control the thickness of the light control layer to be formed uniformly, a spacer may be mixed with the solution of the liquid crystal material and the monomer or oligomer, or the spacer may be applied on one of the substrates. .

As the polymerization initiator, for example, 2-hydroxy-2-methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck), 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Geigy). Irgacure 184 "), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-
On (Merck "Darocur 1116"), benzyl dimethyl ketal (Ciba Geigy "Irgacure 651"), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 (Ciba)・ Geigy's "Irgacure 907"), 2,4-diethylthioxanthone (Nippon Kayaku's "Kayacure DET"
X ”) and ethyl p-dimethylaminobenzoate (“ Kayacure-EPA ”manufactured by Nippon Kayaku Co., Ltd.), isopropylthioxanthone (“ Cantacure ITX ”manufactured by Ward Prekinsop) and ethyl p-dimethylaminobenzoate. And the like, and liquid 2-hydroxy-2-methyl-1-phenylpropan-1-one is particularly preferable in terms of compatibility with the liquid crystal material and the polymer-forming monomer or oligomer.

As a method of forming a light control layer having a transparent solid substance having a uniform three-dimensional network structure in a continuous layer of a liquid crystal material, for example, a liquid crystal material and a polymer-forming monomer or oligomer can be used. And, if necessary, a uniform solution with a photopolymerization initiator is sandwiched between two transparent substrates having transparent electrode layers while maintaining an isotropic liquid state, or on one of the substrates. It may be applied using a coater such as a spin coater, and then the other substrate may be superposed, and this is irradiated with radiation such as ultraviolet rays or electron beams, or thermally polymerized and cured to give a three-dimensional network. Forming a synthetic resin layer. At this time, it is particularly preferable to irradiate with ultraviolet rays.

However, the method for uniformly forming the transparent solid substance having a three-dimensional network structure is not limited to these methods.

If the average diameter of the three-dimensional network structure of the formed transparent solid substance is too large or too small as compared with the wavelength of light, the light scattering property tends to deteriorate, so 0.2
The range of ˜2 μm is preferable. Further, the layer thickness of the layer having a transparent solid substance is in the range of 2 to 15 μm in order to obtain a sufficient contrast between the opacity due to light scattering and the electrically achieved transparency, depending on the purpose of use. preferable.

Further, the twisted
In the nematic liquid crystal display panel, a twisted nematic liquid crystal display element which is usually used alone can be used without particular limitation.

For example, the two polarizing plates used in the twisted nematic liquid crystal display panel having a twist angle in the range of 70 to 110 ° may be so-called normally white or normally black, and emphasis is placed on contrast or visual characteristics. You can choose timely depending on the importance.

Similarly, the two polarizing plates used in the twisted nematic liquid crystal display panel having a twist angle in the range of 180 to 270 ° may be of so-called yellow mode or blue mode, and emphasis is placed on contrast or visual characteristics. You can choose at any time.

Similarly, a color polarizing plate and a color filter can be used according to the purpose. Examples of the polarizing plate that can be used in the present invention include a neutral gray polarizing plate “LLC2-81-12” manufactured by Sanritsu Electric Co., Ltd.
S ", red color polarizing plate" SCR-18 ", blue color polarizing plate" SCB-18 ", green color polarizing plate" SCG- "
18 "and a magenta color polarizing plate" SCM-18 ".

The position of the color filter 9 in FIGS. 5 and 6 depends on the application such as large-scale display and precision display and the cost, and in the panel B, the substrate 1 and the polarizing plate 4, which are not in contact with the panel A, or the polarizing plate. It may be provided between the plate 4 and the reflection plate 7, or the color filter may be provided below the polarizing plate 4 without using the reflection plate 7.

The position of the phase plate 10 in FIGS. 7 and 8 depends on the application such as large-scale display and precision display and the cost, and in the panel B, the substrate 1 on the side in contact with the panel A and the polarizing plate 4, or the panel A. It may be provided between the substrate 1 and the polarizing plate 4 which are not in contact with.

As a method for fixing the light-scattering liquid crystal liquid crystal display panel A and the twisted nematic liquid crystal display panel B, a fixing method using an adhesive, a curable resin or the like can be used. It can also be fixed by using a polarizing plate having adhesive layers on both sides as a polarizing plate of a nematic liquid crystal display panel.

However, the method of fixing the panel is not particularly limited to these methods, and an air layer may exist between the panel A and the panel B.

The layer thickness of each panel constituting the light-scattering liquid crystal two-layer panel of the present invention produced by such a method is preferably in the range of 2 to 30 μm, particularly preferably in the range of 5 to 20 μm.

[0079]

EXAMPLES The present invention will be described in more detail below by showing Examples of the present invention. However, the invention is not limited to these examples.

(Example 1)

[0081]

[Chemical 1]

A liquid crystal composition (A) consisting of was prepared. The properties of this liquid crystal composition (A) were as follows. Transition temperature 77 ℃ (N-I point) -8 ℃ (C-N point) refractive index _{n e = 1.716 n o = 1.509} △ n = 0.207 threshold voltage (V _th) 1.21V Viscosity at 20 ° C. 57.1 c.p. (At the above transition temperature, C represents a crystalline phase, N represents a nematic phase, and I represents an isotropic liquid phase.)

80% by weight of this liquid crystal composition (A), 19.8% by weight of trimethylolpropane triacrylate as a transparent solid substance-forming monomer, and 2-hydroxy-2-methyl-1-phenylpropane-as a polymerization initiator.
A dimming layer forming material consisting of 0.2 wt% of 1 on was prepared,
A small amount of alumina powder having an average particle size of 10 μm was added as a spacer and was interposed between glass plates having two ITO electrodes of 20 cm × 20 cm, and this was irradiated with ultraviolet rays to cure (polymerize) the monomer. The curing condition is that the substrate holding the light control layer forming material is a metal halide lamp (80
It was passed under W / cm ² ) at a speed of 3.5 m / min and irradiated with ultraviolet rays. The applied energy corresponds to 500 mJ / cm ² .

The electrode spacing of the obtained liquid crystal device was 11 μm.
When the cross section of the light control layer was observed with a scanning electron microscope, a transparent solid substance having a three-dimensional network structure could be observed. The obtained liquid crystal device was designated as panel A.

Next, two neutral gray polarizing plates "LLC2-81-12S" (manufactured by Sanritsu Denki Co., Ltd.) which were orthogonal to each other were provided, and a liquid crystal material "RDX-5082" (manufactured by Rodic Co.) was sandwiched. A twisted nematic liquid crystal display panel was manufactured, and a twisted panel having a reflection plate on one surface of the polarizing plate and a twist angle of 90 °.
The nematic liquid crystal display panel is referred to as panel B.

A light-scattering liquid crystal two-layer panel of the present invention was prepared by stacking the panel A upward and the polarizing plate surface of the panel B.

The applied voltage of panel A and panel B is turned off.
[(A) in FIG. 1] and when panel A is driven at 20V and panel B is driven at 5V [(b) in FIG. 1]
And the contrast was 32: 1.

(Comparative Example 1) A panel A was prepared in the same manner as in Example 1, and a black back screen was placed behind the panel A to prepare a liquid crystal device. The contrast of the obtained liquid crystal device was 6: 1.

(Example 2) In Example 1, instead of using the neutral gray polarizing plate having a reflecting plate,
A liquid crystal two-layer panel was produced in the same manner as in Example 1 except that the red color polarizing plate “SCR-18” (manufactured by Sanritsu Electric Co., Ltd.) having a reflecting plate was used. The obtained liquid crystal device showed a clear display of white and red.

(Examples 3 to 5) In the same manner as in Example 2,
Blue color polarizing plate "SCB-18" (manufactured by Sanritsu Electric Co., Ltd.),
Green color polarizing plate "SCG-18" (manufactured by Sanritsu Electric Co., Ltd.),
When a liquid crystal two-layer panel was manufactured using a magenta color polarizing plate “SCM-18” (manufactured by Sanritsu Electric Co., Ltd.), clear color display was obtained with each liquid crystal two-layer panel.

Example 6 Panel B in Example 1
A direct-view light-scattering liquid crystal two-layer panel was prepared in the same manner as in Example 1 except that a TFT-twisted nematic liquid crystal panel having an RGB color filter was used as the above. This direct-view type liquid crystal device showed a clear full-color display.

Example 7 Panel B in Example 1
Angle 90 with RGB color filter as
A direct-view, light-scattering liquid crystal two-layer panel was produced in the same manner as in Example 1 except that the twisted nematic liquid crystal panel of 3 ° was used. This direct-view type liquid crystal device showed a clear full-color display.

Example 8 Panel B in Example 1
A direct-view light-scattering liquid crystal two-layer panel was produced in the same manner as in Example 1 except that a twisted nematic liquid crystal panel having a twist angle of 240 ° was used. This direct-view type liquid crystal device showed a clear black and white display.

Example 9 Panel A in Example 1
A direct-view light-scattering liquid crystal two-layer panel was manufactured in the same manner as in Example 1 except that a light-scattering liquid crystal panel having an active element for each pixel was used. This direct-view type liquid crystal device showed a clear black and white display.

(Embodiment 10) The direct-view light-scattering liquid crystal 2 is manufactured in the same manner as in Embodiment 1 except that a light-scattering liquid crystal panel having an active element for each pixel is used as the panel A in the embodiment 8. A layer panel was prepared. This direct-view type liquid crystal device showed a clear black and white display.

[0096]

The light-scattering liquid crystal two-layer panel of the present invention is a liquid crystal device having an extremely high contrast when compared with the conventional single-layer light-scattering liquid crystal device when it is used as a direct view type.

Further, a liquid crystal two-layer panel using a twisted nematic liquid crystal panel having a color polarizing plate as shown in FIGS. 3 and 4 is a direct-view color type which has hitherto been impossible with a light scattering type liquid crystal device alone. Display is now possible.

Further, as shown in FIGS. 5 and 6, a liquid crystal two-layer panel using a TFT-twisted nematic liquid crystal panel with an RGB color filter has heretofore been impossible with a light scattering type liquid crystal device. Direct-view full-color display is now possible.

Further, the light-scattering type liquid crystal two-layer panel of the present invention can be formed into various types of two-layer panels by selecting the twist angle of the liquid crystal material or the presence or absence of the active element or the non-linear element. Obtainable.

Therefore, the liquid crystal device of the present invention is useful as a direct-view type display device such as a display device of a computer terminal.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example in which two polarizing plates are arranged orthogonally to each other in a monochrome type light-scattering liquid crystal two-layer panel of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example in which two polarizing plates are arranged in parallel with each other in the monochrome light-scattering liquid crystal two-layer panel of the present invention.

FIG. 3 is a schematic cross-sectional view showing an example in which two polarizing plates are arranged orthogonally to each other in the color-type light-scattering liquid crystal two-layer panel of the present invention.

FIG. 4 is a schematic cross-sectional view showing an example in which two polarizing plates are arranged in parallel with each other in the color-type light-scattering liquid crystal two-layer panel of the present invention.

FIG. 5 is a schematic cross-sectional view showing an example in which two polarizing plates are arranged in parallel with each other in the full-color light-scattering liquid crystal two-layer panel of the present invention.

FIG. 6 is a schematic cross-sectional view showing an example in which two polarizing plates are arranged orthogonally to each other in the full-color light-scattering liquid crystal two-layer panel of the present invention.

FIG. 7 is a schematic cross-sectional view showing an example in which two polarizing plates are arranged so as to be in a yellow mode in the black and white light-scattering liquid crystal two-layer panel of the present invention.

FIG. 8 is a schematic cross-sectional view showing an example in which two polarizing plates are arranged so as to be in a blue mode in the black-and-white light-scattering liquid crystal two-layer panel of the present invention.

[Explanation of symbols]

 1 Substrate 2 Transparent Electrode Layer 3 Liquid Crystal Material 4 Polarizing Plate 5 Light Control Layer 6 Sealant 7 Reflector 8 Color Polarizing Plate 9 RGB Color Filter 10 Phase Plate

Claims (9)

[Claims] 1. A light-scattering liquid crystal display panel comprising a light control layer sandwiched between two transparent substrates having a transparent electrode layer, the light control layer containing a liquid crystal material and a transparent solid substance. And a twisted nematic liquid crystal display panel having two polarizing plates.
Layer panel. 2. The light-scattering liquid crystal two-layer panel according to claim 1, wherein at least one of the two polarizing plates is a color polarizing plate. 3. The twisted nematic liquid crystal display panel according to claim 1, wherein the twist angle of the liquid crystal material is in the range of 70 to 110 °. 4. In a twisted nematic liquid crystal display panel, the twist angle of the liquid crystal material is 180 to 270.
2. The light-scattering type liquid crystal two-layer panel according to claim 1, which is in the range of .degree. 5. The light-scattering type liquid crystal two-layer panel according to claim 3 or 4, wherein the twisted nematic liquid crystal display panel has a color filter layer. 6. An active element or a non-linear element is provided for each pixel of the light scattering type liquid crystal display panel.
The light-scattering liquid crystal two-layer panel described. 7. The light-scattering type liquid crystal two-layer panel according to claim 3, wherein an active element or a non-linear element is provided for each pixel of the twisted nematic liquid crystal display panel. 8. The light-scattering liquid crystal two-layer panel according to claim 4, wherein an active element or a non-linear element is provided for each pixel of the light-scattering liquid crystal display panel. 9. The light-scattering type liquid crystal double layer according to claim 1, wherein the light control layer contains a transparent solid substance having a three-dimensional network structure in a continuous layer of a liquid crystal material. panel.