JP2002012865A - Liquid crystal optical modulation element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal optical modulation element comprising three liquid crystal layers of an R liquid crystal layer carrying out the red display, a G liquid crystal layer carrying out the green display and a B liquid crystal layer carrying out the blue display, capable of providing characteristics such as a good color purity or light reflectance, improving the contrast, having a wide temperature range to a practically usable extent and capable of suppressing the driving voltage to a low value. SOLUTION: This liquid crystal optical modulation element comprises a liquid crystal composition 21r which is a liquid crystal obtained by adding 5-25 wt.% of a chiral material to a nematic liquid crystal and having 0.16-0.20 refractive index anisotropy and 7-40 permittivity anisotropy, a liquid crystal composition 21g that is a liquid crystal prepared by adding 10-30 wt.% of a chiral material to the nematic liquid crystal and having 0.13-0.18 refractive index anisotropy and 8-40 permittivity anisotropy and a liquid crystal composition 21b which is a liquid crystal obtained by adding 15-40 wt.% of a chiral material to the nematic liquid crystal and having 0.13-0.20 refractive index anisotropy and 8-35 permittivity anisotropy in the liquid crystal optical modulation element capable of respectively modulating light in specific wavelength regions by each liquid crystal layer of the R liquid crystal layer r, the G liquid crystal layer g and the B liquid crystal layer b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, various researches have been made on liquid crystal light modulation devices using a chiral nematic liquid crystal which exhibits a cholesteric phase at room temperature by adding a chiral material to the nematic liquid crystal.

Such a liquid crystal light modulation element is used, for example, as a reflection type liquid crystal display element utilizing selective reflection of a chiral nematic liquid crystal. In this reflection type liquid crystal display element, display is performed by switching the liquid crystal between a planar state (colored state) and a focal conic state (transparent state) by applying a high or low pulse voltage. In addition, the area that was in the planar state even after the application of the pulse voltage is maintained in the planar state, and the area that was in the focal conic state is maintained in the focal conic state. It is also referred to as bistability or memory property.) It is also possible to keep the display even after the voltage application is stopped.

As one method for realizing a full-color display of the liquid crystal display device (liquid crystal light modulation device), there are a R liquid crystal layer for performing red display, a G liquid crystal layer for performing green display, and a B liquid crystal layer for performing blue display. It is conceivable to employ a liquid crystal light modulation device including three liquid crystal layers.

[0005]

However, in a conventional reflection type liquid crystal light modulation device using a chiral nematic liquid crystal, an R liquid crystal layer for displaying red, a G liquid crystal layer for displaying green, and a blue display are used. In the case of employing a liquid crystal light modulation element including three liquid crystal layers of the B liquid crystal layer, in image display, the light reflectance is still not sufficiently high, and it is difficult to obtain sufficient contrast between the planar state and the focal conic state. This is the actual situation, and characteristics such as color purity (stimulus purity) are not sufficiently satisfactory. In addition, in this type of liquid crystal light modulation element, it is required that the temperature range be expanded to such an extent that it can be actually used, and that the driving voltage be suppressed.

Accordingly, the present invention provides a liquid crystal light modulation device including three liquid crystal layers, an R liquid crystal layer for displaying red, a G liquid crystal layer for displaying green, and a B liquid crystal layer for displaying blue. It is an object of the present invention to provide a liquid crystal light modulation element capable of obtaining characteristics such as light reflectance.

Further, the present invention provides an R liquid crystal layer for displaying red,
It is an object to provide a liquid crystal light modulation element including three liquid crystal layers, a G liquid crystal layer for performing green display and a B liquid crystal layer for performing blue display, and capable of improving contrast.

The present invention also provides an R liquid crystal layer for displaying red,
It is an object of the present invention to provide a liquid crystal light modulation element including three liquid crystal layers, a G liquid crystal layer for displaying green and a B liquid crystal layer for displaying blue, which has a temperature range large enough for practical use. And

Further, the present invention provides an R liquid crystal layer for displaying red,
An object of the present invention is to provide a liquid crystal light modulation element including three liquid crystal layers, a G liquid crystal layer for performing green display and a B liquid crystal layer for performing blue display, in which a driving voltage can be suppressed low. .

[0010]

Means for Solving the Problems The present inventor has conducted various studies to solve the above-mentioned problems, and has found the following.

That is, a liquid crystal light modulating element including three liquid crystal layers, each including a liquid crystal composition, an R liquid crystal layer for performing red display, a G liquid crystal layer for performing green display, and a B liquid crystal layer for performing blue display. In a liquid crystal light modulation device in which each liquid crystal layer modulates light in a specific wavelength range, a chiral material is used as a liquid crystal composition in each liquid crystal layer, in a nematic liquid crystal having an isotropic phase transition temperature of 90 ° C. to 150 ° C. When a chiral nematic liquid crystal exhibiting a cholesteric phase at room temperature, which is added in a fixed amount, is used, more specifically, as a liquid crystal composition in the R liquid crystal layer, a chiral material is added to the nematic liquid crystal in an amount of 5% by weight to 25% by weight. Having a refractive index anisotropy of 0.16 to 0.20 and a dielectric anisotropy of 7 to 4
A chiral nematic liquid crystal having a refractive index anisotropy of 0.13 to 0.18, wherein a chiral material is added to the nematic liquid crystal in an amount of 10 to 30% by weight as a liquid crystal composition in the G liquid crystal layer. A chiral nematic liquid crystal having a dielectric anisotropy of 8 to 40 was used. As a liquid crystal composition in the B liquid crystal layer, a chiral material was added to the nematic liquid crystal in an amount of 15 to 40% by weight. When a chiral nematic liquid crystal having a dielectric anisotropy of 0.13 to 0.20 and a dielectric anisotropy of 8 to 35 is used, characteristics such as good color purity and light reflectance are obtained, and the contrast is improved. In addition, the temperature range is large enough to be practically used, and the driving voltage can be kept low.

The present invention is based on this finding,
In order to solve the above problems, each including a liquid crystal composition,
A liquid crystal light modulating element including three liquid crystal layers of an R liquid crystal layer for displaying red, a G liquid crystal layer for displaying green, and a B liquid crystal layer for displaying blue, each of which modulates light in a specific wavelength range. The liquid crystal composition in the R liquid crystal layer is obtained by adding a chiral material to a nematic liquid crystal having an isotropic phase transition temperature of 90 ° C. to 150 ° C. in an amount of 5% to 25% by weight. A chiral nematic liquid crystal exhibiting a cholesteric phase at room temperature having a property of 0.16 to 0.20 and a dielectric anisotropy of 7 to 40, wherein the liquid crystal composition in the G liquid crystal layer has an isotropic phase transition temperature of 90 ° C. to 150 ° C. A chiral nematic liquid exhibiting a cholesteric phase at room temperature having a refractive index anisotropy of 0.13 to 0.18 and a dielectric anisotropy of 8 to 40 obtained by adding a chiral material to a nematic liquid crystal of 10 to 30% by weight to , And the liquid crystal composition in the B liquid crystal layer, the nematic liquid crystal is isotropic phase transition temperature of 90 ° C. to 150 DEG ° C., chiral material 15 wt% to 40 wt%
Provided is a liquid crystal light modulating element characterized by being a chiral nematic liquid crystal exhibiting a cholesteric phase at room temperature having a refractive index anisotropy of 0.13 to 0.20 and a dielectric anisotropy of 8 to 35 added.

The liquid crystal light modulation device according to the present invention can be used as a reflection type liquid crystal display device utilizing selective reflection of a chiral nematic liquid crystal.

In the liquid crystal light modulation element of the present invention used as the reflection type liquid crystal display element, for example, the liquid crystal is switched between a planar state (colored state) and a focal conic state (transparent state) by applying a high or low pulse voltage. I do. In addition, the region that was in the planar state after the application of the pulse voltage is kept in the planar state, and the region that was in the focal conic state is kept in the focal conic state, so that the display is maintained even after the voltage application is stopped. It is also possible.

According to the liquid crystal light modulation device of the present invention, the liquid crystal composition in each of the R, G, and B liquid crystal layers is obtained by adding a chiral material to a nematic liquid crystal having an isotropic phase transition temperature of 90 ° C. to 150 ° C. 5% to 25% by weight, 10
% To 30% by weight and 15% to 40% by weight, respectively.
13 to 0.18 and 0.13 to 0.20, and a chiral nematic liquid crystal exhibiting a cholesteric phase at room temperature having a dielectric anisotropy of 7 to 40, 8 to 40 and 8 to 35, respectively. , Light reflectivity, etc., and the contrast can be improved. In addition, the temperature range is large enough to enable actual use, and the driving voltage can be suppressed low.

The chiral nematic liquid crystal in each of the liquid crystal layers may have a different refractive index anisotropy. This makes it easy to adjust each composition.

In the liquid crystal light modulation device according to the present invention, a more preferable range of the isotropic phase transition temperature of the nematic liquid crystal used is about 95 ° C. to 135 ° C.

In the liquid crystal light modulation device according to the present invention, a dye may be added to the liquid crystal composition used.

When a dye is added to the liquid crystal composition, various dyes conventionally known can be used as the dye to be added, and those having good compatibility with the liquid crystal are preferable.
For example, an azo compound, a quinone compound, an anthraquinone compound, or a dichroic dye can be used, and a plurality of these dyes may be used. The addition amount is, for example, 3 to the total amount of the nematic liquid crystal and the chiral material.
% By weight or less is desirable.

Further, a color filter can be employed instead of adding a dye to the liquid crystal composition. In this case, for example, a filter layer can be provided on the liquid crystal light modulation element.
As a material that can be used for the filter layer, for example, a colorless transparent substance to which a dye is added, or a material that is originally colored without adding a dye may be used. For example, the filter layer may be a thin film made of a specific substance having the same function as a dye. The same effect can be obtained by replacing the transparent substrate itself for forming the liquid crystal light modulation element with the above filter layer material.

In the liquid crystal light modulation device of the present invention, the following cases can be exemplified as the chiral nematic liquid crystal in each liquid crystal layer. (A) When the isotropic phase transition temperature is 70 ° C to 100 ° C. (B) When a plurality of types of chiral materials are included. (C) The case where the above (a) and (b) are combined.

In any case, a more preferable range of the isotropic phase transition temperature of the chiral nematic liquid crystal in each of the liquid crystal layers is, for example, about 70 ° C. to 95 ° C.

In any case, the nematic liquid crystal in each of the liquid crystal layers may contain at least one of a liquid crystal ester compound, a liquid crystal pyrimidine compound, a liquid crystal trans compound and a liquid crystal stilbene compound.

The liquid crystal ester compound, the liquid crystal pyrimidine compound, the liquid crystal tolan compound and the liquid crystal stilbene compound make it difficult to obtain a chiral nematic liquid crystal exhibiting a desired cholesteric phase even if the amount is too small or too large. Therefore, each of the liquid crystal compounds may be used alone or in a total of 25% by weight or more, more preferably 3% by weight or more of the nematic liquid crystal.
It is preferably contained at 0% by weight or more, more preferably 30% by weight to 90% by weight, further preferably 45% by weight to 80% by weight.

The general structural formula of a liquid crystalline tolan compound usable as a nematic liquid crystal is represented by (A), and specific examples thereof include the chemical structural formulas (A ₁ ) to (A ₁₁₂ ).

[0026]

Embedded image

[0027]

Embedded image

[0028]

Embedded image

[0029]

Embedded image

[0030]

Embedded image

[0031]

Embedded image

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

[0035]

Embedded image

[0036]

Embedded image

[0037]

Embedded image

[0038]

Embedded image

The general structural formula of a liquid crystalline ester compound usable as a nematic liquid crystal is represented by (B), and specific examples thereof include the chemical structural formulas (B ₁ ) to (B ₈₄ ).

[0040]

Embedded image

[0041]

Embedded image

[0042]

Embedded image

[0043]

Embedded image

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image

[0047]

Embedded image

[0048]

Embedded image

[0049]

Embedded image

The general structural formula of the liquid crystalline pyrimidine compound usable as a nematic liquid crystal is represented by (C), and specific examples thereof include the chemical structural formulas (C ₁ ) to (C ₈₆ ).

[0051]

Embedded image

[0052]

Embedded image

[0053]

Embedded image

[0054]

Embedded image

[0055]

Embedded image

[0056]

Embedded image

[0057]

Embedded image

[0058]

Embedded image

[0059]

Embedded image

[0060]

Embedded image

The general structural formula of a liquid crystalline stilbene compound usable as a nematic liquid crystal is represented by (D), and specific examples thereof include chemical structural formulas (D ₁ ) to (D ₆₄ ).

[0062]

Embedded image

[0063]

Embedded image

[0064]

Embedded image

[0065]

Embedded image

[0066]

Embedded image

[0067]

Embedded image

[0068]

Embedded image

[0069]

Embedded image

As the chiral material to be added, for example,
Various conventionally known chiral materials such as biphenyl compounds, terphenyl compounds, ester compounds, pyrimidine compounds, azoxy compounds, and tolan compounds having an optically active group at the terminal group can be used. In addition, a cholesteric liquid crystal having a cholesteric ring represented by cholesteric nanorate can be used.

As described above, plural kinds of chiral materials may be mixed and used as the chiral material to be added to the nematic liquid crystal, but a combination of chiral materials having different optical rotatory powers may be used. The use of multiple types of chiral materials
In addition to changing the phase transition temperature of the cholesteric liquid crystal, reducing the change in the selective reflection wavelength according to the temperature change, it also adjusts the physical properties of the cholesteric liquid crystal such as dielectric anisotropy, refractive index anisotropy and viscosity. It has a function of improving the characteristics as a liquid crystal display element.

The selective reflection wavelength can be adjusted by changing the amount of the chiral material added. Generally, as the amount of the chiral material added increases, the selective reflection wavelength shifts to the shorter wavelength side. The selective reflection wavelength refers to, for example, a peak wavelength in a visible light region of a reflected light spectrum when the liquid crystal enters a planar state by application of a pulse voltage.

[0073]

Embodiments of the present invention will be described below with reference to the drawings.

The liquid crystal light modulation device according to the present invention can be formed, for example, in the following structure. (Configuration and Display Operation of First Embodiment) FIG. 1 shows a first embodiment of the present invention.
It is the schematic which shows the cross-section of the liquid crystal light modulation element (liquid crystal display element) which is an embodiment, Comprising: The planar state (R (red) G (green) B when a high voltage pulse is applied to FIG.
(B) (colored state), and FIG. (B) shows the focal conic state (transparent / black display state) when a low voltage pulse is applied. This liquid crystal display element has a memory property, and the planar state and the focal conic state are maintained even after the pulse voltage is applied. That is, the region that was in the planar state even after the application of the pulse voltage is maintained in the planar state, and the region that was in the focal conic state is maintained in the focal conic state.

The liquid crystal light modulating device shown in FIG. 1 includes an R liquid crystal layer r (red layer) for displaying red and a G liquid crystal layer g for displaying green, which include liquid crystal compositions 21r, 21g, and 21b, respectively.
(A green layer) and a B liquid crystal layer b (blue layer) for displaying blue are laminated in this order.

In addition to the liquid crystal light modulating element shown in FIG. 1, the liquid crystal light modulating element of the present invention can include a pair of substrates in each of the R, G, and B liquid crystal layers. Can be formed.

In each of the liquid crystal layers r, g, b in FIG.
Reference numerals 1 and 12 denote transparent substrates having a light-transmitting property.
Transparent electrodes 13 and 14 formed in a plurality of strips parallel to each other are provided on the respective surfaces of 1 and 12. These electrodes 13 and 14 face each other so as to cross each other. It is preferable that an insulating thin film is coated on the electrode. Here, an insulating thin film 15 is coated on the electrode 13. In addition, a visible light absorbing layer is provided on the outer surface (back surface) of the substrate on the side opposite to the side on which light is incident, if necessary. Here, a visible light absorbing layer 16 is provided on the back surface of the substrate 12 in the red layer r.

Reference numeral 20 denotes a columnar structure as a space holding member, and reference numerals 21r, 21g, and 21b denote liquid crystal compositions exhibiting a cholesteric phase at room temperature. These materials and their combinations will be specifically described by the following experimental examples. I do. 2
Reference numeral 4 denotes a sealing material, which is a liquid crystal composition 21r, 21g, 21g.
This is for sealing b between the substrates 11 and 12. 2
Reference numeral 5 denotes a pulse power supply, which applies a predetermined pulsed voltage to the electrodes 13 and 14. (Substrate) The substrates 11 and 12 each have translucency as described above. However, a pair of substrates that can be used in the liquid crystal light modulation element of the present invention, including the substrates 11 and 12, include: It is necessary that at least one has a light transmitting property.
As a substrate having a light-transmitting property, a glass substrate can be used. In addition to this glass substrate, for example, a flexible substrate made of polycarbonate, polyethersulfone, polyethylene terephthalate, or the like can be used. (Electrode) As an electrode, for example, ITO (Indium Tin O
xide), a transparent conductive film, a metal electrode of aluminum, silicon, etc., or amorphous silicon, BS
A photoconductive film such as O (Bismuth Silicon Oxide) can be used.

In the liquid crystal light modulation device of FIG. 1, as described above, a plurality of strip-shaped transparent electrodes 13 and 14 parallel to each other are formed on the surfaces of the transparent substrates 11 and 12 and these electrodes 13 and 14 are formed. Are facing each other so as to cross each other.

To form an electrode in this way, for example,
After forming an ITO film on the substrate by sputtering, etc.
What is necessary is just to pattern by a photolithography method. (Insulating Film, Alignment Control Film) The liquid crystal light modulating element of the present invention, including the liquid crystal light modulating element shown in FIG. 1, has a function of preventing short-circuit between electrodes and serving as a gas barrier layer to improve the reliability of liquid crystal. A conductive thin film may be formed. As described above, the electrode 13 is coated with the insulating thin film 15 here. Further, an orientation control film can be provided on the substrate as needed.

Examples of the insulating thin film include an inorganic film such as silicon oxide and / or an organic film such as polyimide resin, epoxy resin, acrylic resin and urethane resin. Further, as a material which can be used for the insulating thin film, a polyimide resin or a silicon resin which functions as an alignment control film may be used. Further, the insulating thin film also functions as a color filter if a dye is added to the above-mentioned material. Further, the same material as the polymer used for the columnar structure may be used as the material of the insulating thin film. (Spacer) The liquid crystal light modulation element of the present invention, including the liquid crystal light modulation element shown in FIG. 1, may be provided with a spacer between a pair of substrates for maintaining a uniform gap between the substrates. Although not shown in FIG. 1, the liquid crystal light modulation element of this example has a spacer inserted between the substrates 11 and 12.

As the spacer, a sphere made of resin or inorganic oxide can be exemplified. Although both the spacer and the columnar structure may be provided as in this example, only the spacer may be used as the space holding member instead of the columnar structure. (Liquid crystal composition) The liquid crystal composition in the R liquid crystal layer r (red layer) is obtained by adding a chiral material to a nematic liquid crystal having an isotropic phase transition temperature of 90 ° C to 150 ° C in an amount of 5% by weight to 25% by weight. Anisotropy 0.16-0.2, dielectric anisotropy 7-
It is a chiral nematic liquid crystal showing a cholesteric phase at room temperature of 40.

The liquid crystal composition in the G liquid crystal layer g (green layer) is obtained by adding a chiral material to a nematic liquid crystal having an isotropic phase transition temperature of 90 ° C. to 150 ° C. in an amount of 10 to 30% by weight. 0.13-0.18, dielectric anisotropy 8
It is a chiral nematic liquid crystal showing a cholesteric phase at room temperature of 40.

The liquid crystal composition in the B liquid crystal layer b (blue layer) is obtained by adding a chiral material in an amount of 15 to 40% by weight to a nematic liquid crystal having an isotropic phase transition temperature of 90 to 150 ° C. 0.13-0.2, dielectric anisotropy 8-
35 is a chiral nematic liquid crystal exhibiting a cholesteric phase at room temperature. (Columnar Structure) In the liquid crystal light modulation device of the present invention including the liquid crystal light modulation device shown in FIG. 1, a structure may be supported between a pair of substrates in order to impart strong self-holding properties. In the liquid crystal light modulation device of this example, a columnar structure 20 is provided between the substrates 11 and 12.

First, the structure of the columnar structure will be described. Examples of the columnar structure include columnar structures such as a columnar body, a square columnar body, and an elliptical columnar body arranged at a predetermined interval in a predetermined pattern such as a lattice arrangement. Further, stripe-shaped ones arranged at predetermined intervals may be used. This columnar structure is not a random arrangement, an equidistant arrangement, an arrangement in which the interval gradually changes, an arrangement in which a predetermined arrangement pattern is repeated at a constant cycle, etc., can appropriately maintain a gap between both substrates, and It is preferable that the array is designed so as not to hinder image display. The columnar structure has an area ratio of 1 to the liquid crystal light modulation element display area.
% To 40%, practically satisfactory characteristics as a liquid crystal display element can be obtained while maintaining appropriate strength.

Next, the materials will be described. The columnar structure can be formed, for example, using a polymerizable composition obtained by adding a polymerization initiator to a polymerizable monomer (monomer). As the polymerizable composition, for example, a commercially available photocurable resin material composed of a mixture of a photocurable monomer or oligomer and a photopolymerization initiator can be used. When the photocurable resin material is irradiated with light and polymerized to form a columnar structure, it is easy to arrange the columnar structure at a predetermined shape and at an interval. As a particularly preferable material constituting the columnar structure, a material mainly containing an acrylate compound can be exemplified. The acrylate ester is an acrylate compound or a methacrylate compound having two or more allyl groups, and a structure such as an aromatic ring may be included on the main chain between the allyl groups. CO, C
A divalent group such as O ₂ , CH ₂ and O may be contained.
The acrylate compound also includes an epoxy acrylate compound, a urethane acrylate compound, and the like.

Next, a method of manufacturing the columnar structure will be described. For example, first, an ultraviolet curable compound (composition for forming a columnar structure) is sandwiched between a substrate on which an ITO electrode is formed and a mask on which a predetermined pattern is formed, or an electrode of the substrate is formed. An ultraviolet-curable compound is applied on the surface, and a mask is put on the surface, and ultraviolet light is applied to the mask.
Next, the mask is peeled off, and the unexposed portion of the compound is washed with a predetermined solvent, dried and cured.

Further, after a mixture of a liquid crystal material and a photocurable resin material is sandwiched between glass substrates in advance, a photomask is placed on the glass substrate and light irradiation is performed to perform polymerization phase separation, thereby obtaining a columnar structure. It is also possible to form objects.

In order to form a liquid crystal light modulation element, a liquid crystal composition may be injected between substrates sandwiching a columnar structure by a vacuum injection method or the like. Alternatively, the liquid crystal composition may be dropped when the substrates are bonded, and the liquid crystal composition may be sealed at the same time as the substrates are bonded.

Further, in order to improve the accuracy of controlling the gap between the substrates, when forming the columnar structure, a spacer material having a size smaller than the thickness of the resin, for example, glass fiber, ball-shaped glass or ceramic powder, or organic material is used. If the spherical particles made of a material are arranged so that the gap is hardly changed by heating or pressurizing, the gap accuracy can be further improved, and the voltage unevenness and the color unevenness can be reduced accordingly. (Structure of Second Embodiment) FIG. 2 shows a sectional structure of a liquid crystal light modulation device according to a second embodiment of the present invention (when a high voltage pulse is applied,
(Planar state). This liquid crystal light modulation element is substantially the same as the liquid crystal light modulation element of the first embodiment shown in FIG. 1 except that no columnar structure is provided in the liquid crystal light modulation element display area. . In the element of FIG. 2, portions having basically the same configuration and operation as those of the element of FIG. 1 are denoted by the same reference numerals. (Structure of Third Embodiment) FIG. 3 shows a sectional structure of a liquid crystal light modulation element according to a third embodiment of the present invention (when a high voltage pulse is applied,
(Planar state). This liquid crystal light modulation device is different from the liquid crystal light modulation device of the second embodiment shown in FIG.
A small columnar structure 20 'extending to the middle of the gap between 1 and 12
Is formed. In the element of FIG. 3, parts having basically the same configuration and operation as those of the element of FIG. 2 are denoted by the same reference numerals. (Structure of Fourth Embodiment) A fourth embodiment of the present invention will be described with reference to FIG.
In the liquid crystal light modulation device shown in (1), columnar structures are formed by a screen printing method.

The columnar structure is formed by the screen printing method, for example, as follows. That is, a screen on which a predetermined pattern is formed is placed on the surface of at least one substrate on which the electrodes and the like are formed, and a printing material (a composition for forming a columnar structure, such as a photocurable resin, etc.) is formed on the screen. ). Then, the squeegee is moved at a predetermined pressure, angle, and speed. Thereby, the printing material is transferred onto the substrate via the pattern of the screen. Next, the transferred material is cured and dried.

When the columnar structure is formed by the screen printing method, the resin material used for the columnar structure is not limited to the above-described photocurable resin, but may be, for example, a thermosetting resin such as an epoxy resin or an acrylic resin, or a thermoplastic resin. Can also be used. As the thermoplastic resin, for example, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polymethacrylate resin, polyacrylate resin, polystyrene resin, polyamide resin, polyethylene resin, polypropylene resin, fluorine resin, Examples thereof include polyurethane resins, polyacrylonitrile resins, polyvinyl ether resins, polyvinyl ketone resins, polyether resins, polyvinyl pyrrolidone resins, saturated polyester resins, polycarbonate resins, chlorinated polyether resins, and the like. The resin material is desirably used as a paste, for example, by dissolving the resin in an appropriate solvent.

When a thermosetting resin or a thermoplastic resin material is used as a resin material for the columnar structure and a spacer is provided between a pair of substrates, for example, a liquid crystal light modulation element can be manufactured as follows. .

That is, first, a resin material is disposed on at least one substrate, and then a spacer is sprayed on at least one substrate, and a pair of substrates are overlapped with the surfaces on which a plurality of strip electrodes and the like are formed facing each other. The resin material is softened by heating the pair of superimposed substrates while applying pressure from both sides, and then solidified again by cooling to form empty cells.

To make this empty cell a liquid crystal light modulator,
The liquid crystal composition may be injected between the substrates sandwiching the columnar structure by, for example, a vacuum injection method.

According to the liquid crystal light modulation elements of the first to fourth embodiments described above, each of the R, G, and B liquid crystal layers r,
The liquid crystal compositions 21r, 21g, and 21b in g and b are:
In a nematic liquid crystal having an isotropic phase transition temperature of 90 ° C. to 150 ° C., a chiral material is added in an amount of 5% by weight to 25% by weight,
0% to 30% by weight and 15% to 40% by weight were added, and the refractive index anisotropy was 0.16 to 0.2 and 0.1 to 0.2%, respectively.
13 to 0.18 and 0.13 to 0.2, and chiral nematic liquid crystal exhibiting a cholesteric phase at room temperature having dielectric anisotropy of 7 to 40, 8 to 40 and 8 to 35, respectively, so that good color purity is obtained. , Light reflectivity, etc., and the contrast can be improved. In addition, the temperature range is large enough to enable actual use, and the driving voltage can be suppressed low. If you want to lower the drive voltage,
It is preferable to increase the dielectric anisotropy. For example, 15
Or more, more preferably 20 or more, still more preferably 25
Above, more preferably 30 or more.

Next, an experiment for evaluating the performance of the liquid crystal light modulation device according to the present invention was conducted.

In each of the following experimental examples, the Y value (luminous reflectance) was measured by a spectrophotometer CM-37 having a white light source.
00d (manufactured by Minolta). The contrast is (Y value in high reflectance state / Y value in low reflectance state)
Value). In the liquid crystal light modulation element in each of the experimental examples described below, the liquid crystal light modulation element is in a high reflectance state when in the planar state, and is in a low reflectance state when in the focal conic state.

In each of the following experimental examples, the values of the helical twist power are shown for the chiral materials E1 to E7 added to the nematic liquid crystal. The helical twist power means a degree of a property of causing a spiral structure in the nematic liquid crystal. In this experimental example, the value is shown as the value of the selective reflection wavelength of a liquid crystal composition obtained by adding 1% by weight of a chiral material to a nematic liquid crystal. The smaller the value, the greater the helical twist power. (Experimental example 1) The chemical structural formulas (C ₁₃ ), (C ₂₁ ), (C
₂₅ ) and the liquid crystalline pyrimidine compound represented by (C ₂₆ )
6% by weight and the chemical structural formulas (A ₃₁ ), (A ₃₉ ),
A nematic liquid crystal having an isotropic phase transition temperature of 109.4 ° C. containing 46% by weight of a liquid crystalline trans compound represented by (A ₄₀ )
Chiral material E1 (helical twist power is about 8μm *
The same applies to the ester-based chiral material in weight%, and the chiral material E1 used in the following experiments. ) At 33.3% by weight
After mixing, a chiral nematic liquid crystal composition exhibiting a selective reflection wavelength of 480 nm was prepared. The chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1911, a dielectric anisotropy of 9.5, and an isotropic phase transition temperature of 80 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a blue layer (B liquid crystal layer) for performing blue display.

Next, the chemical structural formulas (C ₁ ), (C ₂₇ ),
15% by weight of the liquid crystalline pyrimidine compound represented by (C ₂₈ ) or (C ₃₀ ) was added to the above-mentioned chemical structural formulas (A ₃₄ ), (A ₃₅ ),
A nematic liquid crystal having an isotropic phase transition temperature of 99.4 ° C. containing 22% by weight of a liquid crystalline trans compound represented by (A ₃₆ ) was added to a chiral material E2 (an ester-based chiral material having a helical twist power of about 3 μm * weight%; 25.4% by weight of a chiral material E2 used in the following experiment was mixed to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 555 nm. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1773, a dielectric anisotropy of 9, and an isotropic phase transition temperature of 80 ° C. A sealing material XN for sealing the liquid crystal composition around the periphery of one of the two glass substrates on which electrodes are formed.
21S (manufactured by Mitsui Chemicals, Inc.) was formed. The two substrates are opposed to each other, and a gap between the substrates is set to 5 with a spacer interposed therebetween.
μm, and the liquid crystal composition was sandwiched. This was used as a green layer (G liquid crystal layer) for displaying green.

Next, the chemical structural formulas (C ₂ ), (C ₇ ),
29% by weight of the liquid crystalline pyrimidine compound represented by (C ₁₅ ) or (C ₂₀ ) was added to the above chemical groove formulas (A ₃₂ ), (A ₄₆ ),
A nematic liquid crystal having an isotropic phase transition temperature of 129.9 ° C. containing 43% by weight of a liquid crystalline trans compound represented by (A ₄₇ )
Chiral material E3 (helical twist power is about 12μm
* The same applies to the weight percentage of cyanobiphenyl-based chiral material, and chiral material E3 used in the following experiments. ) To 1
8.6% by weight was mixed to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 670 nm. This chiral nematic liquid crystal composition has a refractive index anisotropy of 0.187.
0, dielectric anisotropy was 8.5, and isotropic phase transition temperature was 80 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 9 μm with a spacer interposed between the two substrates to sandwich the liquid crystal composition. This was used as a red layer (R liquid crystal layer) for displaying red.

The above layers are laminated in order of blue layer, green layer, and red layer from the top, and a black layer is formed on the outer surface of the substrate on the side opposite to the side from which light is incident (ie, the back surface of the red layer substrate). A light absorbing layer was provided, and a liquid crystal light modulation device having substantially the same structure as that of the liquid crystal light modulation device shown in FIG. 2 except that no insulating thin film was formed on the electrode was manufactured.

When a pulse voltage of 80 V is applied between the electrodes sandwiching each liquid crystal of the liquid crystal light modulation element for 5 msec, a planar state (white state) is obtained and the Y value is 32.
8 was shown. Furthermore, a pulse voltage of 50 V is applied for 5 m each.
When sec is applied, the lens enters a focal conic state, and Y
The value showed 4.9 and the contrast was 6.69.
Further, it was confirmed that the device normally operates at an ambient temperature of at least 0 ° C to 60 ° C. Experimental Example 2 The chemical structural formulas (B ₁₄ ), (B ₁₅ ), and (B
₁₆ ), a chiral material E1 was added to a nematic liquid crystal having an isotropic phase transition temperature of 98 ° C. containing 56% by weight of a liquid crystalline ester compound represented by (B ₁₇ ), (B ₁₈ ), (B ₁₉ ) or (B ₃₁ ).
The mixture was mixed at 8.7% by weight to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 480 nm. This chiral nematic liquid crystal composition has a refractive index anisotropy of 0.136.
2, the dielectric anisotropy was 19, and the isotropic phase transition temperature was 88 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a blue layer (B liquid crystal layer). Except for the blue layer, a liquid crystal light modulation element was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, the distance between the electrodes sandwiching the liquid crystal is 6.
When a pulse voltage of 0 V was applied for 5 msec, a planar state (white state) was obtained, and the Y value was 32.0. When a pulse voltage of 30 V was further applied for 5 msec, a focal conic state was established, the Y value was 4.6, and the contrast was 6.96. Further, it was confirmed that the device normally operates at an ambient temperature of at least 0 ° C to 60 ° C. Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1. (Experimental example 3) The chemical structural formulas (B ₂₅ ), (B ₂₆ ), (B
₂₇ ), the isotropic phase transition temperature 104 containing 57% by weight of the liquid crystalline ester compound represented by (B ₂₈ ), (B ₂₉ ) or (B ₃₀ ).
A chiral nematic liquid crystal composition having a selective reflection wavelength of 555 nm was prepared by mixing 23.4% by weight of a chiral material E2 with a nematic liquid crystal at a temperature of ℃. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1373, a dielectric anisotropy of 21, and an isotropic phase transition temperature of 93 ° C. A sealing material XN for sealing the liquid crystal composition around the periphery of one of the two glass substrates on which electrodes are formed.
21S (manufactured by Mitsui Chemicals, Inc.) was formed. The two substrates are opposed to each other, and a gap between the substrates is set to 5 with a spacer interposed therebetween.
μm, and the liquid crystal composition was sandwiched. This was used as a green layer (G liquid crystal layer). Except for the green layer, a liquid crystal light modulation device was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, the distance between the electrodes sandwiching the liquid crystal is 6.
When a pulse voltage of 0 V was applied for 5 msec, a planar state (white state) was obtained, and the Y value was 31.1. When a pulse voltage of 30 V was further applied for 5 msec, a focal conic state was established, the Y value was 4.4, and the contrast was 7.07. Further, it was confirmed that the device normally operates at an ambient temperature of at least 0 ° C to 60 ° C. Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1. (Experimental Example 4) The chemical structural formulas (B ₂₁ ), (B ₂₂ ), and (B
₂₃ ), 51% by weight of the liquid crystalline ester compound represented by (B ₂₄ ) or (B ₃₂ ) and the chemical structural formula (A ₄₂ ),
The liquid crystalline trans compound represented by (A ₄₈ ) or (A ₄₉ )
12.1% by weight of a chiral material E3 was mixed with a nematic liquid crystal having an isotropic phase transition temperature of 103 ° C. containing 7% by weight to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 670 nm. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1920, a dielectric anisotropy of 25, and an isotropic phase transition temperature of 80 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 9 μm with a spacer interposed between the two substrates to sandwich the liquid crystal composition. This was used as a red layer (R liquid crystal layer). Except for the red layer, a liquid crystal light modulation device was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, 6 electrodes are interposed between the electrodes sandwiching the liquid crystal.
When a pulse voltage of 0 V was applied for 5 msec, a planar state (white state) was obtained, and the Y value was 29.5. When a pulse voltage of 35 V was further applied for 5 msec, a focal conic state was established, the Y value was 4.9, and the contrast was 6.02. Further, it was confirmed that the device normally operates at an ambient temperature of at least 0 ° C to 60 ° C. Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1. (Experimental Example 5) The chemical structural formulas (D ₁ ), (D ₂ ), (D
₃ ) A chiral material E3 was added to a nematic liquid crystal having an isotropic phase transition temperature of 99 ° C. containing 67% by weight of a liquid crystalline stilbene compound represented by (D ₄₉ ), (D ₅₀ ), (D ₆₀ ) or (D ₆₁ ).
6.4% by weight were mixed to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 670 nm. This chiral nematic liquid crystal composition has a refractive index anisotropy of 0.185.
0, dielectric anisotropy of 10, and isotropic phase transition temperature of 75 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 9 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a red layer (R liquid crystal layer). Except for the red layer, a liquid crystal light modulation device was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, the distance between the electrodes sandwiching the liquid crystal is 9.
When a pulse voltage of 5 V was applied for 5 msec, a planar state (white state) was obtained, and the Y value was 28.8. When a pulse voltage of 60 V was further applied for 5 msec, a focal conic state was established, the Y value was 4.7, and the contrast was 6.13. Further, it was confirmed that the device normally operates at an ambient temperature of at least 0 ° C to 60 ° C. Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1. Experimental Example 6 The chemical structural formulas (C ₁₄ ), (C ₂₂ ), and (C
₂₃ ) and the liquid crystalline pyrimidine compound represented by (C ₂₄ )
9% by weight and the chemical structural formulas (A ₄₃ ), (A ₄₄ ),
A nematic liquid crystal having an isotropic phase transition temperature of 130 ° C. containing 20% by weight of a liquid crystalline tolan compound represented by (A ₄₅ ), 17.8% by weight of a chiral material E3 and 7.6 of a chiral material E2.
% By weight to prepare a chiral nematic liquid crystal composition exhibiting a selective reflection wavelength of 490 nm. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.195, a dielectric anisotropy of 13.3, and an isotropic phase transition temperature of 70 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a blue layer (B liquid crystal layer). Except for the blue layer, a liquid crystal light modulation element was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, the distance between the electrodes sandwiching the liquid crystal is 6.
When a pulse voltage of 0 V was applied for 5 msec, a planar state (white state) was obtained, and the Y value was 27.1. When a pulse voltage of 35 V was further applied for 5 msec, a focal conic state was established, the Y value was 4.5, and the contrast was 6.02. Further, it was confirmed that the device normally operates at an ambient temperature of at least 0 ° C to 60 ° C. Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1. Experimental Example 7 The chemical structural formulas (C ₁ ), (C ₂₇ ), and (C
₂₈ ), the liquid crystalline pyrimidine compound represented by (C ₃₀ )
5% by weight and the chemical structural formulas (A ₃₄ ), (A ₃₅ ),
38% by weight of a chiral material E1 was mixed with a nematic liquid crystal having an isotropic phase transition temperature of 99.4 ° C. containing 22% by weight of a liquid crystalline tolan compound represented by (A ₃₆ ) and a selective reflection wavelength of 480
A chiral nematic liquid crystal composition exhibiting nm was prepared. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1875, a dielectric anisotropy of 25, and an isotropic phase transition temperature of 82 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a blue layer (B liquid crystal layer).

Next, the chemical structural formulas (C ₂ ), (C ₇ ),
29% by weight of the liquid crystalline pyrimidine compound represented by (C ₁₅ ) or (C ₂₀ ) was added to the above-mentioned chemical structural formulas (A ₃₂ ), (A ₄₆ ),
In a nematic liquid crystal having an isotropic phase transition temperature of 129 ° C. containing 43% by weight of a liquid crystalline tolan compound represented by (A ₄₇ ), 10% by weight of a chiral material E2 and 10% by weight of a chiral material E4 (having a helical twist power of about 22 μm * weight%) Cholesteric chiral material, chiral material E4 used in the following experiments
The same is true for ) Was mixed at a selective reflection wavelength of 5%.
A chiral nematic liquid crystal composition exhibiting 55 nm was prepared. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1750, a dielectric anisotropy of 30, and an isotropic phase transition temperature of 84 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which the electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a green layer (G liquid crystal layer).

Next, the chemical structural formulas (C ₂ ), (C ₇ ),
29% by weight of the liquid crystalline pyrimidine compound represented by (C ₁₅ ) or (C ₂₀ ) was added to the above-mentioned chemical structural formulas (A ₃₂ ), (A ₄₆ ),
A nematic liquid crystal having an isotropic phase transition temperature of 129.9 ° C. containing 43% by weight of a liquid crystalline trans compound represented by (A ₄₇ )
Chiral material E5 (Helical twist power is about 15μm
The same applies to the phenylcyclohexyl-based chiral material of *% by weight, and the chiral material E5 used in the following experiments. )
Was mixed at 23% by weight to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 670 nm. This chiral nematic liquid crystal composition has a refractive index anisotropy of 0.17,
The dielectric anisotropy was 9, and the isotropic phase transition temperature was 76 ° C.
A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 9 μm with a spacer interposed between the two substrates to sandwich the liquid crystal composition.
This was used as a red layer (R liquid crystal layer). Hereinafter, a liquid crystal light modulation element was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, a pulse voltage of 55 V is applied between the electrodes sandwiching each liquid crystal of the liquid crystal light modulation element for 5 ms.
When ec is applied, a planar state (white state) is obtained, and Y
The value showed 31.4. Further, when a pulse voltage of 30 V is applied for 5 msec, a focal conic state is obtained, the Y value is 4.8, and the contrast is 6.54.
Met. Experimental Example 8 The chemical structural formulas (A ₄₂ ), (A ₄₃ ), and (A
₄₈ ), a chiral material E7 (having a helical twist power of about 3 μm * weight%) containing 38% by weight of a liquid crystalline tolan compound represented by (A ₄₉ ) and (A ₅₀ ) and having an isotropic phase transition temperature of 105 ° C. 17% by weight of an ester-based chiral material (the same applies to the chiral material E7 used below) was mixed to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 480 nm. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1741, a dielectric anisotropy of 32, and an isotropic phase transition temperature of 85 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a blue layer (B liquid crystal layer).

Next, the chemical structural formula (A ₄₂ ),
The liquid crystalline trans compound represented by (A ₄₈ ) or (A ₄₉ )
5% by weight and the chemical structural formulas (B ₂₅ ), (B ₂₆ ) and (B
₂₇ ), (B ₂₈ ), (B ₂₉ ), an isotropic phase transition temperature 1 containing 45% by weight of a liquid crystalline ester compound represented by (B ₃₀ ).
12% by weight of a chiral material E7 was mixed with a nematic liquid crystal at 02 ° C. to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 560 nm. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1624, a dielectric anisotropy of 36, and an isotropic phase transition temperature of 82 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a green layer (G liquid crystal layer).

Next, the chemical structural formula (A ₄₂ ),
The liquid crystalline trans compound represented by (A ₄₈ ) or (A ₄₉ )
0% by weight and the chemical structural formulas (B ₂₅ ), (B ₂₆ ), (B
₂₇ ), (B ₂₈ ), (B ₂₉ ), an isotropic phase transition temperature containing 50% by weight of a liquid crystalline ester compound represented by (B ₃₀ ).
7% by weight of chiral material E7 in nematic liquid crystal at 04 ° C
The mixture was mixed to prepare a chiral nematic liquid crystal composition exhibiting a selective reflection wavelength of 655 nm. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1685, a dielectric anisotropy of 38, and an isotropic phase transition temperature of 86 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 8 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a red layer (R liquid crystal layer).

Each of the above layers is laminated from the top in the order of blue layer, green layer, and red layer, and a black layer is formed on the outer surface of the substrate on the side opposite to the side from which light is incident (ie, the back surface of the red layer substrate). A light absorbing layer was provided. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, a pulse voltage of 45 V is applied for 5 ms between electrodes sandwiching each liquid crystal of the liquid crystal light modulation element.
When ec is applied, a planar state (white state) is obtained, and Y
The value showed 31.5. Further, when a pulse voltage of 25 V was applied for 5 msec each, a focal conic state (black state) was obtained, the Y value was 4.8, and the contrast was 6.56.

Comparative Example 1 The chemical structural formulas (B ₉ ), (B ₁₀ ), (B ₁₁ ), (B ₁₂ ), (B ₁₃ ),
A chiral material E6 (having a helical twist power of about 6) was added to a nematic liquid crystal having an isotropic phase transition temperature of 102 ° C. containing 58% by weight of a liquid crystalline ester compound represented by (B ₆₅ ) or (B ₆₆ ).
32.5% by weight of 5 μm * weight% of an ester-based chiral material) and 2.9% by weight of a chiral material E1 were mixed to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 480 nm. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.090, a dielectric anisotropy of 15, and an isotropic phase transition temperature of 80 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a blue layer (B liquid crystal layer). Except for the blue layer, a liquid crystal light modulation element was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, when a pulse voltage of 50 V was applied between the electrodes of the liquid crystal light modulation element for 5 msec, a planar state (white state) was obtained, and the Y value was 23.0. When a pulse voltage of 30 V was further applied for 5 msec, a focal conic state was established, the Y value was 6, and the contrast was 3.83. Further, it was confirmed that the device normally operates at an ambient temperature of at least 0 ° C to 60 ° C. Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1. Comparative Example 2 The chemical structural formulas (A ₁₂ ), (A ₂₄ ),
100% by weight of a liquid crystalline trans compound represented by (A ₃₈ )
13.5% by weight of chiral material E3 and 6% by weight of chiral material E5 in a nematic liquid crystal having an isotropic phase transition temperature of 65 ° C.
After mixing, a chiral nematic liquid crystal composition having a selective reflection wavelength of 680 nm was prepared. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.235, a dielectric anisotropy of 5, and an isotropic phase transition temperature of 50 ° C. A sealing material XN21 for sealing the liquid crystal composition around the periphery of one of the two glass substrates on which electrodes are formed.
S (manufactured by Mitsui Chemicals, Inc.) was formed. The two substrates are opposed to each other, and a space between the substrates is set to 9 μm with a spacer interposed therebetween.
And the liquid crystal composition was sandwiched. This was used as a red layer (R liquid crystal layer). Except for the red layer, a liquid crystal light modulation device was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, when a pulse voltage of 110 V was applied between the electrodes of the liquid crystal light modulation element for 5 msec, a planar state (white state) was obtained, and the Y value was 18.7.
When a pulse voltage of 55 V was further applied for 5 msec, a focal conic state was established, the Y value was 6.2, and the contrast was 3.02. When the ambient temperature is 60
When the temperature reached around ℃, display could not be performed normally. Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1. (Comparative Experimental Example 3) The chemical structural formulas (B ₂₅ ), (B ₂₆ ),
_{(B 27), (B 28} ), (B 29), (B 30) liquid crystal ester compound isotropic phase transition temperature 1 containing 57 wt% represented by
45% by weight of a chiral material E3 was mixed with a nematic liquid crystal at 04 ° C. to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 480 nm. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1420, a dielectric anisotropy of 9, and an isotropic phase transition temperature of 91 ° C. A sealing material XN2 for sealing the liquid crystal composition around the periphery of one of the two glass substrates on which electrodes are formed.
1S (manufactured by Mitsui Chemicals, Inc.) was formed. The two substrates are opposed to each other, and a gap between the substrates is 5 μm with a spacer interposed between the two substrates.
m, and the liquid crystal composition was sandwiched. This was used as a blue layer (B liquid crystal layer). Except for the blue layer, a liquid crystal light modulation element was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, when a pulse voltage of 95 V was applied between the electrodes of the liquid crystal light modulation element for 5 msec, a planar state (white state) was obtained, and the Y value was 19.8. When a pulse voltage of 65 V was further applied for 5 msec, a focal conic state was established, the Y value was 5.8, and the contrast was 3.41. Further, it was confirmed that the device normally operates at an ambient temperature of at least 0 ° C to 60 ° C. Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1. Comparative Example 4 The chemical structural formulas (C ₁₃ ), (C ₂₁ ),
A nematic liquid crystal having an isotropic phase transition temperature of 92 ° C. containing 32% by weight of a liquid crystalline pyrimidine compound represented by (C ₂₅ ) or (C ₂₆ ) is provided with 15% by weight of a chiral material E4 and a chiral material E5.
Was mixed at 7% by weight to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 555 nm. This chiral nematic liquid crystal composition has a refractive index anisotropy of 0.085,
The dielectric anisotropy was 3.6 and the isotropic phase transition temperature was 70 ° C.
A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched.
This was used as a green layer (G liquid crystal layer). Except for the green layer, a liquid crystal light modulation device was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, when a pulse voltage of 120 V was applied between the electrodes of the liquid crystal light modulating element for 5 msec, a planar state (white state) was obtained, and the Y value was 17.9.
When a pulse voltage of 65 V was further applied for 5 msec, a focal conic state was established, the Y value was 6.3, and the contrast was 2.84. Further, it was confirmed that the device normally operates at an ambient temperature of at least 0 ° C to 60 ° C. Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1. Comparative Example 5 The chemical structural formulas (A ₁ ), (A ₂ ),
28% by weight of a chiral material E1 is mixed with a nematic liquid crystal having an isotropic phase transition temperature of 63 ° C. containing 43% by weight of a liquid crystalline tolan compound represented by (A ₃ ), (A ₄ ) and (A ₅ ), and selectively reflected. A chiral nematic liquid crystal composition having a wavelength of 480 nm was prepared. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.1305, a dielectric anisotropy of 8, and an isotropic phase transition temperature of 52 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 5 μm with a spacer interposed between the two substrates, and the liquid crystal composition was sandwiched. This was used as a blue layer (B liquid crystal layer).

The chemical structural formulas (B ₉ ), (B ₁₀ ) and (B
₁₁ ) A chiral material E2 was added to a nematic liquid crystal having an isotropic phase transition temperature of 102 ° C. containing 58% by weight of a liquid crystalline ester compound represented by (B ₁₂ ), (B ₁₃ ), (B ₆₅ ) or (B ₆₆ ).
5% by weight and 5% by weight of a chiral material E5 were mixed to prepare a chiral nematic liquid crystal composition having a selective reflection wavelength of 670 nm. This chiral nematic liquid crystal composition had a refractive index anisotropy of 0.095, a dielectric anisotropy of 16, and an isotropic phase transition temperature of 79 ° C. A sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) for sealing the liquid crystal composition was formed on the periphery of one of the two glass substrates on which electrodes were formed. The two substrates were opposed to each other, and a gap between the substrates was adjusted to 9 μm with a spacer interposed between the two substrates to sandwich the liquid crystal composition. This was used as a red layer (R liquid crystal layer). Except for the blue layer and the red layer, a liquid crystal light modulation element was manufactured in the same manner as in Experimental Example 1. The same evaluation as in Experimental Example 1 was performed on this liquid crystal light modulation element.

That is, when a pulse voltage of 70 V was applied between the electrodes of the liquid crystal light modulating element for 5 msec, a planar state (white state) was obtained, and the Y value was 18.3. When a pulse voltage of 40 V was further applied for 5 msec, a focal conic state was established, the Y value was 6.4, and the contrast was 2.86. The ambient temperature is 60 ° C
The display could not be performed normally when it was near.
Note that voltages were applied to the other liquid crystal layers under the same conditions as in Experimental Example 1.

As described above, the contrasts of the liquid crystal light modulation devices of Experimental Examples 1 to 8 are 6.02 to 7.07,
In each case, the contrast was high. On the other hand, in the liquid crystal light modulation elements of Comparative Examples 1 to 5, the contrast was 2.
84 to 3.83, and the contrast was low in each case.

[0124]

As described above, according to the present invention, a liquid crystal light modulation element including three liquid crystal layers of an R liquid crystal layer for displaying red, a G liquid crystal layer for displaying green, and a B liquid crystal layer for displaying blue is provided. Thus, it is possible to provide a liquid crystal light modulation element capable of obtaining characteristics such as good color purity and light reflectance.

Further, according to the present invention, there is provided a liquid crystal light modulation element including three liquid crystal layers of an R liquid crystal layer for performing red display, a G liquid crystal layer for performing green display, and a B liquid crystal layer for performing blue display. The present invention can provide a liquid crystal light modulation element that can be operated.

According to the present invention, there is provided a liquid crystal light modulating element including three liquid crystal layers of an R liquid crystal layer for performing red display, a G liquid crystal layer for performing green display, and a B liquid crystal layer for performing blue display. It is possible to provide a liquid crystal light modulation element having a temperature range as large as possible.

According to the present invention, there is provided a liquid crystal light modulation device including three liquid crystal layers, an R liquid crystal layer for performing red display, a G liquid crystal layer for performing green display, and a B liquid crystal layer for performing blue display. A liquid crystal light modulation element that can be kept low can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a cross-sectional structure of a liquid crystal light modulation element (liquid crystal display element) according to first and fourth embodiments of the present invention. FIG. 1A shows a planer when a high-voltage pulse is applied. It is a figure which shows a state (R (red) G (green) B (blue) coloring state), and figure (B) is a figure which shows the focal conic state (transparent / black display state) when a low voltage pulse is applied. is there.

FIG. 2 is a schematic diagram illustrating a cross-sectional structure (in a planar state when a high-voltage pulse is applied) of a liquid crystal light modulation element according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating a cross-sectional structure (in a planar state when a high-voltage pulse is applied) of a liquid crystal light modulation element according to a third embodiment of the present invention.

[Explanation of symbols]

 r R liquid crystal layer for red display (red layer) g G liquid crystal layer for green display (green layer) b B liquid crystal layer for blue display (blue layer) 11, 12 transparent substrate 13, 14 transparent electrode 15 insulating thin film Reference Signs List 16 visible light absorbing layer 20 columnar structure 20 'small columnar structure 21r, 21g, 21b liquid crystal composition 24 sealing material 25 pulse power supply

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 19/34 C09K 19/34 G02F 1/13 500 G02F 1/13 500 505 505 1/139 1/137 505 (72) Inventor Nobuyuki Kobayashi 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Co., Ltd. International Building Minolta Co., Ltd. F-term (reference) 2H088 EA44 GA02 GA03 GA17 JA04 MA06 4H027 BA02 BD02 BD07 BD09 BE02 BE03 BE04 CB04 CC04 CN01 CN04 CP04 DE04 DE05 DF04

Claims (6)

[Claims] 1. A liquid crystal light modulation device comprising three liquid crystal layers, each comprising a liquid crystal composition, an R liquid crystal layer for displaying red, a G liquid crystal layer for displaying green, and a B liquid crystal layer for displaying blue. In a liquid crystal light modulation element in which each liquid crystal layer modulates light in a specific wavelength range, the liquid crystal composition in the R liquid crystal layer has an isotropic phase transition temperature of 9
A chiral material is added to a nematic liquid crystal at 0 ° C. to 150 ° C. in an amount of 5% by weight to 25% by weight.
A chiral nematic liquid crystal exhibiting a cholesteric phase at room temperature, having a dielectric anisotropy of 6 to 0.20 and a liquid crystal composition in the G liquid crystal layer having an isotropic phase transition temperature of 9;
A chiral material is added to a nematic liquid crystal at 0 ° C. to 150 ° C. in an amount of 10% by weight to 30% by weight.
A chiral nematic liquid crystal exhibiting a cholesteric phase at room temperature having a dielectric anisotropy of 8 to 40;
A chiral material is added to a nematic liquid crystal at 0 ° C. to 150 ° C. in an amount of 15% by weight to 40% by weight.
A liquid crystal light modulation device comprising a chiral nematic liquid crystal having a cholesteric phase at room temperature, having a dielectric anisotropy of 13 to 0.20 and a dielectric anisotropy of 8 to 35. 2. The liquid crystal light modulation device according to claim 1, wherein the chiral nematic liquid crystal in each of the liquid crystal layers has a different refractive index anisotropy. 3. The liquid crystal according to claim 1, wherein the nematic liquid crystal in each of the liquid crystal layers contains at least one of a liquid crystal ester compound, a liquid crystal pyrimidine compound, a liquid crystal trans compound, and a liquid crystal stilbene compound. Light modulation element. 4. The nematic liquid crystal in each of the liquid crystal layers contains a liquid crystalline ester compound, a liquid crystalline pyrimidine compound, a liquid crystalline tolan compound and a liquid crystalline stilbene compound alone or in a total of 25% by weight or more. Liquid crystal light modulator. 5. The liquid crystal light modulation device according to claim 1, wherein the chiral nematic liquid crystal in each of the liquid crystal layers has an isotropic phase transition temperature of 70 ° C. to 100 ° C. 6. The chiral nematic liquid crystal in each liquid crystal layer contains a plurality of types of chiral materials.
6. The liquid crystal light modulation device according to any one of items 1 to 5.