JP2001033805A - Liquid crystal optical modulation element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal optical modulation element having a laminated structure which enables high-quality full-color display. SOLUTION: The device is a full-color liquid crystal display element having three liquid crystal display cells 110R, 110G, 110B laminated. In each cell, a liquid crystalline composition 17 containing a liquid crystal compound and an additive is sealed, and components of the liquid crystal composition in one cell are different from the components of the liquid crystal composition in at least one of other cells. The liquid crystal composition 17 in each cell reflects light at a specified wavelength as the peak wavelength to display a full-color image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal light modulation device,
More specifically, the present invention relates to a liquid crystal light modulation device in which a plurality of cells are stacked.

[0002]

BACKGROUND OF THE INVENTION In recent years, research / development of display devices using liquid crystals has been active. In particular, a display element using a chiral nematic liquid crystal composition exhibiting a cholesteric phase at room temperature by adding a chiral material to a nematic liquid crystal, a guest having a dichroic dye added to a nematic liquid crystal,
Attention has been paid to host-type display elements.

Incidentally, as one method of realizing the above-mentioned full-color display element, it is conceivable to adopt a structure in which a plurality of cells for displaying each color are stacked. However, a liquid crystal display element having a laminated structure having display characteristics and drive characteristics suitable for practical use has not yet been realized.

An object of the present invention is to provide a novel liquid crystal light modulation device having a novel laminated structure capable of displaying high quality images. Further, another object of the present invention is to provide an easy drive control.
An object of the present invention is to provide a liquid crystal light modulation element having a novel laminated structure.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, a liquid crystal light modulation device according to the first invention is formed by laminating a plurality of liquid crystal layers each containing a liquid crystal composition, and each liquid crystal layer emits light of a specific wavelength range. In the liquid crystal light modulation element for modulating the liquid crystal, the composition type of the liquid crystal composition contained in the liquid crystal layer is different for each liquid crystal layer.

[0006] By making the composition type of the liquid crystal composition contained in the liquid crystal layer different for each liquid crystal layer, it is possible to provide an optimum light modulation characteristic for each liquid crystal layer. High-quality light modulation characteristics can be achieved for the entire modulation element.

A liquid crystal light modulation device according to a second aspect of the present invention is a liquid crystal light modulation device in which a plurality of liquid crystal layers each containing a liquid crystal composition are laminated, and each liquid crystal layer modulates light in a specific wavelength range. The liquid crystal layer is characterized in that at least two liquid crystal layers having different composition types and different thicknesses of the liquid crystal composition contained in the liquid crystal layer are included.

[0008] By providing at least two liquid crystal layers having different composition types and different thicknesses of the liquid crystal composition, it is possible to easily suppress the variation of the driving voltage of each liquid crystal layer while providing the optimum light modulation characteristics. It becomes possible.

In the liquid crystal light modulation device according to a second aspect of the present invention, the plurality of liquid crystal layers have different thicknesses from each other, and the liquid crystal composition contained in the thicker layer has a higher dielectric anisotropy than the other. A large set of liquid crystal layers may be included. The larger the dielectric anisotropy, the smaller the voltage for coloring / decoloring the liquid crystal layer. Therefore, with such a configuration, it is possible to more accurately cancel the variation in the driving voltage of each liquid crystal layer.

Further, the liquid crystal composition contained in the liquid crystal layer in which the dielectric anisotropy of the liquid crystal composition is larger than the other may include a liquid crystal compound having a polar group. The liquid crystal compound having a polar group is selected from the group consisting of a liquid crystal ester compound, a liquid crystal pyrimidine compound, a liquid crystal cyanobiphenyl compound, a liquid crystal cyanophenylcyclohexane compound, a liquid crystal cyanoterphenyl compound, and a liquid crystal difluorostilbene compound. At least one liquid crystalline compound.

Further, the thicknesses of the plurality of liquid crystal layers may all be different, or the dielectric anisotropy of the liquid crystal composition contained in each liquid crystal layer may all be different. This increases the degree of freedom in designing the liquid crystal composition contained in the liquid crystal layer,
Light modulation characteristics required for each liquid crystal layer can be optimized.

A liquid crystal light modulating element according to a third aspect of the present invention is a liquid crystal light modulating element in which a plurality of liquid crystal layers each containing a liquid crystal composition are laminated, and each liquid crystal layer modulates light in a specific wavelength range. The liquid crystal layer is characterized by including at least two liquid crystal layers having different types of liquid crystal compositions contained in the liquid crystal layer and having the same driving voltage range.

By providing at least two liquid crystal layers having different composition types of the liquid crystal composition and having the same drive voltage range, it is possible to facilitate the drive control while having an optimum light modulation characteristic.

In the liquid crystal light modulation device according to a third aspect of the present invention, the driving voltage ranges of the plurality of liquid crystal layers may be all equal. In this case, drive control becomes easier.

In any of the liquid crystal light modulation elements according to the second and third aspects of the invention, the composition types of the liquid crystal compositions of all the liquid crystal layers may be different from each other. By doing so, it is possible to provide an optimal light modulation characteristic for each liquid crystal layer, and it is possible to display a high quality image as a whole liquid crystal light modulation element having a laminated structure.

In each of the liquid crystal light modulation elements according to the first, second and third aspects, the liquid crystal composition contained in each liquid crystal layer may include a liquid crystal compound and an additive. . Then, the type of the additive included in the liquid crystal composition of one liquid crystal layer may be different from the type of the additive included in the other liquid crystal layer, or may be included in the liquid crystal composition of one liquid crystal layer. The kind of the liquid crystal compound to be used may be different from the kind of the liquid crystal composition contained in another liquid crystal layer.

The additive may include a compound having at least one asymmetric carbon. By adding such an additive to a nematic liquid crystal as a chiral material, a liquid crystal composition exhibiting a cholesteric phase at room temperature can be obtained. By changing the amount and type of the chiral material, characteristics such as the selective reflection wavelength of the liquid crystal composition can be changed.

The additive may be a polychromatic dye. By using a polychromatic dye, the color purity of the display color of the liquid crystal layer can be improved.

The liquid crystal layer may be switchable between a selective reflection state and a transmission state. For example, the liquid crystal composition may exhibit a cholesteric phase at room temperature. In this case, the plurality of liquid crystal layers are composed of three layers: a blue liquid crystal layer for displaying blue, a green liquid crystal layer for displaying green, and a red liquid crystal layer for displaying red, which are sequentially stacked from the light incident side. Then, a good full-color image can be displayed.

The liquid crystal layer may be switchable between a state of absorbing light in a specific wavelength range and a transmitting state.
Each liquid crystal layer may perform display by the guest-host effect. Such display can be realized, for example, by using a liquid crystal composition obtained by adding a polychromatic dye as an additive to a nematic liquid crystal. In this case, the liquid crystal layer can be switched between a colored state and a transparent state by controlling the direction of the dye molecules by changing the molecular arrangement of the liquid crystal.

A color filter may be arranged between at least one pair of adjacent liquid crystal layers. By disposing a color filter, the color purity of the display on the liquid crystal layer can be increased,
The viewing angle characteristics can be improved.

It is preferable that each liquid crystal layer is sandwiched between a pair of substrates. At least one of the pair of substrates may have flexibility. By using a flexible substrate, a flexible liquid crystal display element can be obtained. In particular, when a resin film substrate is used, the weight of the liquid crystal display element can be reduced.

A resin structure may be arranged in a light modulation region between a pair of substrates sandwiching a liquid crystal layer. By arranging the resin structure, the distance between the substrates is accurately kept constant, and the thickness of the liquid crystal layer becomes uniform. In addition, even when a flexible substrate is used, the distance between the substrates can be favorably maintained, and the area can be easily increased.

Each liquid crystal layer may be a composite film in which the liquid crystal composition is dispersed in a network polymer matrix.
By doing so, the area can be easily increased, and the viewing angle characteristics can be improved.

A functional thin film may be provided on at least one of the pair of substrates sandwiching the liquid crystal layer, and the thickness of the functional thin film may be equal for each liquid crystal layer. This way,
The structure of the substrate with the functional thin film of each liquid crystal layer can be made the same, and the manufacture becomes easy.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the liquid crystal light modulation device according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration of a liquid crystal display device 10 according to a first embodiment of the present invention. The liquid crystal display element 10 includes a liquid crystal display cell 110R including a red display layer 11R that can be switched between a red selective reflection state and a transparent state, and a liquid crystal display cell 110 that includes a green display layer 11G that can be switched between a green selective reflection state and a transparent state.
G and a liquid crystal display cell 110B including a blue display layer 11B that can be switched between a blue selective reflection state and a transparent state. Further, a light absorbing layer 19 is provided on the reflection side in the viewing direction indicated by the arrow A.

Each of the liquid crystal display cells 110R, 110G, 11
In FIG. 0B, a liquid crystal composition 17 is sealed between the transparent substrates 12, respectively. Electrodes are formed on the inner surface of the substrate 12, and an insulating film and / or an orientation control film are further formed as necessary. Details of these are described below with reference to FIGS. 2, 3, and 4. I do.

(First Example of Cell Structure, see FIG. 2) FIG. 2 shows an arbitrary one of the liquid crystal display cells 110R, 110G and 110B. On the surface of each substrate 12, there are provided a plurality of transparent electrodes 13 and 14 formed in a plurality of strips parallel to each other. These electrodes 13 and 14 face each other so as to alternate with each other in a matrix. Electrode 1
An insulating film 15 and an orientation control film 16 are formed on 3, and an orientation control film 16 is formed on the electrode 14. As described in detail below, the liquid crystal composition 17 exhibits a cholesteric phase at room temperature.
Sealing between the substrates 12.

(Second example of cell structure, see FIG. 3) FIG. 3 shows an arbitrary one of the liquid crystal display cells 110R, 110G and 110B. The basic configuration is the same as that of the cell 110 shown in FIG. 2, and a columnar structure 22 made of a polymer substance is formed between the substrates 12.

(Third example of cell structure, see FIG. 4) FIG. 4 also shows an arbitrary one of the liquid crystal display cells 110R, 110G and 110B. The basic configuration is the same as that of the cell 110 shown in FIG. 2, and a network polymer matrix 23 is formed between the substrates 12.

(Second Embodiment, see FIG. 5) FIG. 5 shows a schematic configuration of a liquid crystal display element 40 according to a second embodiment of the present invention. The liquid crystal display element 40 includes liquid crystal display cells 41X, 4
It has a two-layer structure of 1Y.

In FIG. 5, the same members as those in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted. Further, the columnar polymer structure 2 shown in FIG.
The network polymer matrix 23 shown in FIG. 2 or FIG. 4 may be formed.

In any of the above embodiments, the multi-layer liquid crystal display device may include at least two liquid crystal layers having different thicknesses. If the thickness of the liquid crystal layer is made different for each layer, the variation in the driving voltage of each liquid crystal layer can be easily canceled.

The plurality of liquid crystal layers include a pair of liquid crystal layers whose thicknesses are different from each other and whose liquid crystal composition contained in the thicker layer has a larger dielectric anisotropy than the other. Is preferred. The larger the dielectric anisotropy, the smaller the voltage for coloring / decoloring the liquid crystal layer. Therefore, with such a configuration, it is possible to more accurately cancel the variation in the driving voltage of each liquid crystal layer.

The thicknesses of the plurality of liquid crystal layers may all be different, and the liquid crystal compositions contained in each liquid crystal layer may all have different dielectric anisotropy. In this case, the degree of freedom in designing the liquid crystal composition contained in the liquid crystal layer is increased, and the light modulation characteristics required for each liquid crystal layer can be optimized.

The drive voltages of all the liquid crystal layers may be equal.
By making the drive voltages of all the liquid crystal layers equal, drive control becomes easier and a common drive IC can be used.

(Display Method 1, Case of Using Selective Reflection by Cholesteric Phase) In each cell of the liquid crystal display elements 10 and 40 having the above configuration, display is performed by applying a pulse voltage to the electrodes 13 and 14. Will be That is, when the liquid crystal composition 17 uses a material exhibiting a cholesteric phase, by applying a pulse voltage having a relatively high energy, the liquid crystal is in a planar state, and is determined based on a spiral pitch and a refractive index of liquid crystal molecules. Light of a wavelength is selectively reflected. By applying a pulse voltage of relatively low energy, the liquid crystal is in a focal conic state and is in a transparent state. Each state is maintained even when no voltage is applied.

It has been found that there is also an intermediate state between the focal conic state and the planar state. By applying a pulse voltage of intermediate energy, it is possible to express a halftone. In the intermediate state, it is considered that the focal conic state and the planar state are mixed, and this state is also maintained when no voltage is applied. When the visible light absorbing layer 19 is provided, black is displayed in the focal conic state.

In the present liquid crystal display device, the strip electrodes 13 and 14 are used.
Are the display pixels. In this specification, a region in which light modulation is performed by the liquid crystal is referred to as a light modulation region, and its periphery is outside the light modulation region in which light modulation is not performed. In the present liquid crystal display element, the light modulation area is the display area.

(Display Method 2, Display by Guest-Host Effect) When a material in which a liquid crystal is mixed with a polychromatic dye such as a dichroic dye is used as a liquid crystal composition, a voltage is applied between the electrodes 13 and 14. Since the direction of the molecular axis of the liquid crystal can be changed between when the voltage is applied and when no voltage is applied, it is possible to switch between the colored state and the colorless state.

(Substrate) The substrate 12 needs to be transparent except for at least the lowermost layer. As a transparent substrate, besides glass, polycarbonate (P
C), flexible substrates such as polyethersulfone (PES) and polyethylene terephthalate (PET) can be used.

(Electrode) The electrodes 13 and 14 are made of ITO
A transparent conductive film represented by (Indium Tin Oxide), a metal electrode such as aluminum or silicon, or a photoconductive film such as amorphous silicon or BSO (Bismuth Silicon Oxide) can be used. In order to form the electrodes 13 and 14 in a strip shape, for example, an ITO film may be formed on the substrate 12 by a sputtering method or the like, and then patterned by a photolithography method.

(Insulating film, alignment control film, color filter)
The insulating film 15 is an inorganic film such as silicon oxide or an organic film such as a polyimide resin, an epoxy resin, an acrylic resin, or a urethane resin. The insulating film 15 prevents a short circuit between the electrodes 13 and 14, and improves the reliability of the liquid crystal as a gas barrier layer. It has a function to make Further, a polyimide resin or a silicon resin that functions as the alignment control film 16 may be used. Further, if a pigment is added, it functions as a color filter. Further, the same material as the polymer used for the polymer structure 22 may be used as the insulating film 15.

(Liquid Crystal Composition) In the case of utilizing the selective reflection by the cholesteric phase of a liquid crystal, the liquid crystal composition preferably exhibits a cholesteric phase at room temperature. A chiral nematic liquid crystal obtained by adding a chiral material to a nematic liquid crystal is preferable. The selective reflection wavelength can be adjusted depending on the amount of the chiral material added, and the selective reflection wavelength can be set in the visible light range or outside the visible light range. A dye may be added to the liquid crystal composition. The nematic liquid crystal has rod-shaped liquid crystal molecules arranged in parallel, but does not have a layered structure.

Various types of nematic liquid crystal can be used without any particular limitation. In particular, liquid crystalline ester compounds, liquid crystalline pyrimidine compounds,
A nematic liquid crystal containing a liquid crystal compound having a polar group such as a liquid crystal cyanobiphenyl compound, a liquid crystal cyanophenylcyclohexane compound, a liquid crystal cyanoterphenyl compound, a liquid crystal difluorostilbene compound, and a liquid crystal tolan compound has a dielectric constant of the liquid crystal composition. This is useful for increasing the anisotropy. The nematic liquid crystal may be a mixture of a plurality of liquid crystal compounds. Other than the above compounds,
Liquid crystal components such as polycyclic compounds and N-type compounds for raising the phase transition temperature to an isotropic phase can be included.

The chiral nematic liquid crystal has the advantage that the pitch of the helical structure can be changed by changing the amount of the chiral material added, thereby controlling the selective reflection wavelength of the liquid crystal. Note that, as a general term indicating the pitch of the helical structure of the liquid crystal molecules, “helical pitch” defined by the distance between the liquid crystal molecules when the liquid crystal molecules rotate 360 degrees along the helical structure of the liquid crystal molecules is used. .

Here, the general structural formulas (I) to (VI) of six representative liquid crystal compounds capable of increasing the dielectric anisotropy are shown below.

[0049]

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The chiral material is an additive having a function of twisting the molecules of the nematic liquid crystal when added to the nematic liquid crystal. By adding a chiral material to a nematic liquid crystal, a helical structure of liquid crystal molecules having a predetermined twist interval is generated, thereby exhibiting a cholesteric phase.

The added chiral material contains at least one compound having at least one asymmetric carbon, and the helical sense (the direction of twist given to the liquid crystal) may be the same or different. The addition amount is preferably about 45 wt% or less, more preferably 40 wt% or less, based on the liquid crystal compound. 45wt
%, Defects such as precipitation of crystals are likely to occur. The lower limit of the addition amount of the chiral material is not particularly limited as long as the liquid crystal composition causes selective reflection.
Preferably, the content is 10 wt% or more.

As the chiral material to be added to the nematic liquid crystal, plural kinds of chiral materials may be mixed and used.
In addition to combinations of the same type of optical rotation, combinations of different types of optical rotation can also be used. Use of multiple types of chiral materials and liquid crystal components such as polycyclic compounds and N-type compounds as chiral materials can change the phase transition temperature of cholesteric liquid crystals and reduce the change in selective reflection wavelength according to temperature changes. Besides, it can change various physical property values of the cholesteric liquid crystal such as dielectric anisotropy, refractive index anisotropy and viscosity, and has a function of improving characteristics as a display element.

Here, general structural formulas (A) to (F) and specific structural formulas (A ₁ ) to (A ₁₀ ) of typical chiral materials,
(B ₁ ) to (B ₁₀ ), (C ₁ ) to (C ₁₀ ), (D ₁ )
(D _10), indicating the _{(E 1) ~ (E 10} ), (F 1) ~ (F 9).

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In each of the display layers 11R, 11G, and 11B, the improvement of the color purity of the display performed by selective reflection,
In order to absorb a light component that leads to a decrease in transparency in the transparent state, a dye is added to each display layer, or a colored filter layer having an equivalent effect, that is, a plate member such as a color glass filter or a color film. May be arranged on each display layer. The dye may be added to any of the liquid crystal material, resin material, transparent electrode material, and transparent substrate material constituting each display layer,
More than one of each component may contain a dye. However,
In order not to lower the display quality, it is desirable that the dye to be added and the filter layer to be added do not hinder color display by selective reflection of each display layer.

As the dye to be added to the liquid crystal material, conventionally known various dyes can be used, and those having good compatibility with the liquid crystal are preferable. For example, azo compounds, quinone compounds, anthraquinone compounds and the like, or dichroic dyes and the like can be used, and a plurality of these may be used. From these dyes, a dye that absorbs spectral light in a wavelength region that causes a reduction in display without hindering display by the selective reflection wavelength of the liquid crystal may be appropriately selected and used for each display layer. In addition, since the light component that degrades the display quality is considered to mainly exist on the short wavelength side,
It is more preferable to use a dye that absorbs spectral light in a wavelength range shorter than the selective reflection wavelength of the liquid crystal.

The amount of the dye to be added is not particularly limited as long as the switching operation characteristic for displaying the liquid crystal is not significantly reduced.
It is preferable to add the above, and about 2 wt% is sufficient.

When a color filter is employed in place of the addition of a dye, an additional filter layer material may be a colorless and transparent substance obtained by adding a dye. It may be a material that is inherently colored without adding a dye, or a thin film of a specific substance that functions similarly to the dye.
It is clear that the same effect can be obtained by replacing the transparent substrate 12 itself with the above filter layer material instead of disposing the filter layer.

When utilizing the guest-host effect, it is preferable to use a nematic liquid crystal to which a polychromatic dye such as a dichroic dye is added. As the nematic liquid crystal, the same one as described above can be used.
Further, as the polychromatic dye, the same one as described above can be used.

In any of the embodiments, the plurality of liquid crystal layers include at least two liquid crystal layers having different composition types of the liquid crystal composition contained in each liquid crystal layer.
In order to make the composition type of the liquid crystal composition different, the kind of the liquid crystal compound contained in the liquid crystal composition of one liquid crystal layer is made different from the kind of the liquid crystal composition contained in the other liquid crystal layer, What is necessary is just to make the kind of additive contained in the liquid crystal composition of a liquid crystal layer different from the kind of additive contained in another liquid crystal layer. In the case where display is performed by the guest-host effect, it is preferable to change the composition type of the base nematic liquid crystal because the fluctuation range of the driving voltage due to the addition amount of the polychromatic dye is small.

The composition of the liquid crystal composition contained in the liquid crystal layer may be different for each liquid crystal layer. This makes it possible to provide each liquid crystal layer with an optimum display characteristic, thereby enabling a high-quality display as a whole of the liquid crystal display element having a laminated structure.

Further, the plurality of liquid crystal layers may include at least two liquid crystal layers having different composition types and different thicknesses of the liquid crystal composition contained in the liquid crystal layers. With this configuration, it is possible to easily suppress the variation in the driving voltage of each liquid crystal layer while providing the optimum display characteristics. The thickness of the liquid crystal layer can be controlled by the size of the spacer to be used, and a different size spacer may be used for each liquid crystal layer.

Further, the plurality of liquid crystal layers may include at least two liquid crystal layers having different types of liquid crystal compositions contained in the liquid crystal layers and having the same driving voltage range.
By doing so, the drive control can be facilitated while having the optimal light modulation characteristics. The driving voltage can be realized by appropriately selecting a combination of a liquid crystal compound and an additive, or appropriately adjusting the thickness of a liquid crystal layer.

(Spacer) The spacer 21 is for maintaining the gap between the substrates 12 at a predetermined value.
A spherical or rod-shaped resin or inorganic oxide can be used. It may have a fixing / welding property to the substrate 12. The size of the spacer 21 may be determined according to the gap, but is preferably 1 to 20 μm. When used together with the polymer structure 22, the ratio of the spacer 21 to the polymer structure 22 is preferably set to about 1/2 to 1/200.

(Polymer Structure) The polymer structure 22 may have any shape, such as a columnar body, an elliptical body, or a quadrangular prism, and its arrangement may be random. It may have regularity such as a lattice shape.
By providing such a polymer structure, it is easy to keep the gap between the substrates constant, and the self-holding property of the liquid crystal display element itself can be enhanced. In particular, when dot-shaped polymer structures are arranged at regular intervals, it is easy to make display performance uniform.

In order to form a polymer structure, a photo-curable resin material such as a photoresist material made of an ultraviolet-curable monomer is used to apply a desired thickness to a substrate, and this is irradiated with ultraviolet light through a mask. For example, a so-called photolithography method of performing pattern exposure and removing an uncured portion can be used.

Further, a polymer structure made of a thermoplastic resin may be formed by using a resin material obtained by dissolving a thermoplastic resin in an appropriate solvent. In this case, a resin material is applied onto the substrate from the tip of the nozzle, such as a printing method for printing on the substrate by extruding a thermoplastic resin material with a squeegee using a screen plate or a metal mask, or a dispenser method or an inkjet method. The polymer structure can be disposed by a method of forming by discharging, or a transfer method of transferring a resin material onto a flat plate or a roller and then transferring the resin material to the substrate surface. After the opposing substrate is placed on the polymer structure arranged in this way, by heating and pressing, a liquid crystal cell in which the polymer structure is sandwiched between the substrates can be manufactured.

In order to form a liquid crystal display element, a liquid crystal composition may be injected between substrates sandwiching a polymer structure by a vacuum injection method or the like. 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 polymer 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 When spherical particles made of an organic material are arranged so that the gap is hardly changed by heating or pressing, gap accuracy is further improved, and voltage unevenness, color unevenness and the like can be reduced.

(Polymer Film) The polymer matrix 23 is a composite film that forms a three-dimensional network with the liquid crystal composition. The polymer matrix 23 is obtained by sufficiently mixing a resin material to which a photopolymerization initiator is added and a liquid crystal composition at a predetermined ratio, then dropping the mixture on a substrate, covering another substrate, and bringing the substrate into close contact. It is manufactured by irradiating ultraviolet rays to polymerize the resin material. As the resin material, for example, a methacrylate compound or the like can be used.

(Sealing Material) The sealing material 25 is for enclosing the liquid crystal composition 17 so as not to leak out of the substrate 12, and is made of a thermosetting resin such as an epoxy resin or an acrylic resin, or a photocurable adhesive. Agents and the like can be used.

(Method 1 of Color Display, When Using Selective Reflection by Cholesteric Phase) The display layers 11R, 1
In the liquid crystal display element 10 in which 1G and 11B are stacked, the blue display layer 11B and the green display layer 11G are in a transparent state in which liquid crystals are in a focal conic arrangement, and the red display layer 11R is in a selective reflection state in which liquid crystals are in a planar arrangement. By doing so, red display can be performed. The blue display layer 1
By setting 1B to a transparent state in which the liquid crystal is in a focal conic arrangement, and setting the green display layer 11G and the red display layer 11R to a selective reflection state in which the liquid crystal is in a planar arrangement,
Yellow display can be performed. Similarly, red, green, blue, white, cyan, magenta, yellow, and black can be displayed by appropriately selecting the state of each display layer between a transparent state and a selective reflection state. Furthermore, each display layer 1
By selecting an intermediate selective reflection state as the state of 1R, 11G, 11B, display of an intermediate color becomes possible, and it can be used as a full-color display element.

Further, the order of stacking the display layers 11R, 11G and 11B in the liquid crystal display element 10 may be other than that shown in FIG. However, considering that the transmittance of the light in the long wavelength region is higher than that in the short wavelength region, the selective reflection wavelength of the liquid crystal contained in the upper layer is changed to that of the liquid crystal contained in the lower layer. When the wavelength is shorter than the wavelength, more light is transmitted to the lower layer, so that a bright display can be performed. Therefore, the observation side (the direction of arrow A)
It is most preferable that the display layers become the blue display layer 11B, the green display layer 11G, and the red display layer 11R in this order, and this state provides the most preferable display quality.

(Method 2 of Color Display, When Using the Guest-Host Effect) For example, an image is displayed in a single color using one of the cells of the liquid crystal display element 40 as a background color and the other cell as a display color. . For example, if the lower cell is configured as a display layer that can be switched between a red colored state and a transparent state, and the upper cell is configured as a display layer that can be switched between a blue colored state and a transparent state, a red image is displayed on a blue background. can do. Of course, the combination of the ground color and the display color is arbitrary.

(Example of Manufacturing Cell) Here, an example of manufacturing each cell of the liquid crystal display element will be described. First, a transparent electrode such as an ITO thin film is formed on a substrate 12 such as a resin film by a known sputtering method or the like, and an insulating film and an orientation control film are formed as necessary. Next, a resin material is printed on the substrate 12 by a screen printing machine or the like as shown in FIG. Further, a seal member 25 is provided around the periphery. As a counter substrate, a transparent electrode,
Using an insulating film and an orientation control film formed as necessary, and superposing the substrate so that the transparent electrode surface faces the substrate, FIG.
The liquid crystal composition is dropped between the two substrates by a bonding apparatus having a flat plate 51 and a roller 50 as shown in FIG. Thus, one liquid crystal display cell is manufactured. By changing the liquid crystal composition, a plurality of cells are manufactured in the same manner, and by stacking these cells, a stacked liquid crystal display element that performs color display is manufactured.

(Driving Circuit and Driving Method of Display Element) Since the pixel configuration in each liquid crystal display cell of the liquid crystal display element 10 is a simple matrix, as shown in FIG. 8, the scanning electrodes R1, R2 to Rm and the signal electrodes Mx of C1, C2-Cn
It can be represented by a matrix of n. A pixel at the intersection of the scanning electrode Ra and the signal electrode Cb (a and b are natural numbers satisfying a ≦ m and b ≦ n) is defined as LCa-b. These electrode groups are respectively connected to the scan drive IC 31 and the signal drive I
These drive ICs are connected to the output terminal of C32.
From 31 and 32, a scanning voltage and a selection voltage are applied to each electrode.

The driving circuit of the liquid crystal display element 10 is not limited to the matrix-structured driver.
The image data may be serially transferred from the MPU 32 via a line latch memory. In this case, the scanning drive IC 31 is not line-compatible, but needs to be for serial use, and the cost of the driver is low.

In the liquid crystal display element 10, the display state of the liquid crystal layer is a function of the applied voltage and the pulse width. An example in which display is performed using selective reflection by a cholesteric phase of a liquid crystal will be described. First, each liquid crystal layer is reset to a focal conic state showing the lowest Y value (luminous reflectance). When a pulse voltage having a constant width is applied to the liquid crystal layer, the display state changes as shown in FIG. In FIG. 9, the vertical axis indicates the Y value, and the horizontal axis indicates the applied voltage. When the pulse of the voltage Vp is applied, the planar state indicating the highest Y value is selected, and when the pulse of the voltage Vf is applied, the focal conic state indicating the lowest Y value is selected. When an intermediate voltage is applied, a state in which the planar state and the focal conic state exhibiting an intermediate Y value are mixed is selected, and halftone display becomes possible.

FIG. 10 shows a drive / image signal processing circuit 30 adapted to rewrite image data. The scanning drive IC 31 and the signal drive IC 32 are connected to the liquid crystal display element 10, and these ICs 31 and 32 are driven by control signals from a scan controller 33 and a signal controller 34, respectively. Image data to be newly displayed is input from the memory 36 to the signal controller 34, but is converted into a selection signal by the image data conversion means 35 before that.

(Experimental Example 1) A liquid crystalline phenylcyclohexane compound was contained at 35 wt%, a liquid crystalline ester compound was contained at 30 wt%, and the remaining component was P-type 3
A liquid crystal mixture A comprising a ring compound and an N-type bicyclic compound;
It contains 35% by weight of a liquid crystalline phenylcyclohexane compound and 20% by weight of a liquid crystalline cyanobiphenyl compound.
The liquid crystal mixture B contains 35 wt% of a liquid crystal tran compound and a liquid crystal pyrimidine compound and an N type bicyclic compound. For a liquid crystal mixture C comprising a compound, the above-mentioned chemical formula (C ₉ )
A predetermined amount of chiral material S811 (manufactured by Merck Japan Ltd.), that is, 14 wt% for A and 20 w for B
liquid crystal compositions A1 and B
1, C1 was prepared. The liquid crystal composition A1 was around 680 nm, the liquid crystal composition B1 was around 560 nm, and the liquid crystal composition C1
Is adjusted to selectively reflect light having a wavelength near 480 nm. The dielectric anisotropy Δε of each of the liquid crystal compositions A1, B1, and C1 was 17, 12, 7, and the refractive index anisotropy Δn was 0.21, 0.14, and 0.14.

Next, a polyimide-based orientation control film AL4552 was formed on the transparent electrode forming surface of the PES (polyethersulfone) film on which the patterned transparent electrode was formed.
(Manufactured by JSR) was formed to a thickness of 800 angstroms and used as a first substrate. No rubbing treatment was performed on the orientation control film. Then, on the orientation control film forming surface of the first substrate,
A predetermined amount of spacer of a predetermined size was sprayed. At the same time, an insulating film HIM3000 (manufactured by Hitachi Chemical Co., Ltd.) having a thickness of 20 was formed on another PES film (second substrate) having a transparent electrode.
The alignment control film AL4552 was formed thereon to a thickness of 800 Å. No rubbing treatment was performed on the orientation control film. Subsequently, a sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) was screen-printed around the first substrate to form a sealing wall.

Thereafter, the liquid crystal composition A1 was applied on the first substrate, the first and second substrates were bonded using a bonding apparatus, and heated at 150 ° C. for 1 hour to obtain a liquid crystal display cell for red. Similarly, the first substrate and the second substrate were bonded using the liquid crystal compositions B1 and C1, to obtain green and blue liquid crystal display cells, respectively. The liquid crystal composition A1 has a thickness of 9 μm.
m, the liquid crystal composition B1 was filled in a cell having a thickness of 7 μm, and the liquid crystal composition C1 was filled in a cell having a thickness of 5 μm. These three types of cells were laminated in the order of blue, green, and red as viewed from the observation side, and a black light absorbing film was provided on the back surface of the laminate (the back surface of the cell containing the liquid crystal composition A1). .

When each cell was driven using a pulse voltage having a pulse width of 5 msec to bring the cells into a colored state (planar arrangement) and a decolored state (focal conic arrangement), the contrast of the laminate was 6: 1 (W / B). ) And exhibited extremely excellent display characteristics. The driving voltage was set for each liquid crystal composition A1,
B1 and C1 are 60 V when colored and 30 V when decolored
Met.

The measurement of the reflectance and the like for measuring the contrast was performed using a spectrophotometer CM-3700d (manufactured by Minolta). The same applies to the following experimental examples and comparative examples. The drive voltage range was measured by measuring the minimum voltage required to obtain the strongest colored state in the colored state and the maximum voltage at which the maximum transmittance was obtained in the transparent state. .

(Experimental Example 2) The liquid crystal compositions A1, B1, and C1 shown in Experimental Example 1 were used. Then, an alignment control film AL4 having a thickness of 800 Å was formed on the electrode surfaces of the three PES film substrates on which the transparent electrodes were formed.
552 (manufactured by JSR) was formed, and spacers of a predetermined size were sprayed. On the other hand, the other three PESs having transparent electrodes
An insulating film HIM3000 was formed to a thickness of 2000 Å on the film (second substrate), and an orientation control film AL4552 was formed thereon to a thickness of 800 Å. Subsequently, the sealing material XN is applied to the peripheral portion on the second substrate.
113E (manufactured by Mitsui Chemicals, Inc.) was screen-printed to form a seal wall. Then, the first and second substrates were bonded to each other, and heated at 150 ° C. for 1 hour while applying a predetermined pressure to produce three cells.

Next, 2 wt% of each of the liquid crystal compositions A1, B1 and C1 was added to the acrylate monomer R684.
After adding (Nippon Kayaku Co., Ltd.), each cell was filled by a vacuum injection method. The liquid crystal composition A1 was filled in a cell having a thickness of 9 μm, the liquid crystal composition B1 was filled in a cell having a thickness of 7 μm, and the liquid crystal composition C1 was filled in a cell having a thickness of 5 μm. Thereafter, each cell was irradiated with ultraviolet rays of 15 mW / cm ² for 5 minutes using a high-pressure mercury lamp to form a polymer composite film in the liquid crystal layer, and a liquid crystal display cell for red containing the liquid crystal composition A1 and a liquid crystal composition, respectively. A liquid crystal display cell for green containing B1 and a liquid crystal display cell for blue containing the liquid crystal composition C1 were obtained. These three types of cells were laminated in the order of blue, green, and red as viewed from the observation side, and a black light absorbing film was provided on the back surface of the laminate (the back surface of the cell containing the liquid crystal composition A1). .

When each cell was driven using a pulse voltage having a pulse width of 5 msec to bring the cells into a colored state (planar arrangement) and a decolored state (focal conic arrangement), the contrast of the laminate was 4: 1 (W / B). ) And exhibited extremely excellent display characteristics. The driving voltage was set for each liquid crystal composition A1,
80V for coloring and 50V for decoloring with respect to B1 and C1
Met.

(Experimental Example 3) For the liquid crystal mixtures A, B, and C shown in Experimental Example 1, as chiral materials, R811 represented by the chemical formula (C ₉ ) and R811 represented by the chemical formula (F ₁ ) were used. A predetermined amount of a mixture of CB15 (manufactured by Merck Japan Ltd.) at a ratio of 3: 1, that is,
14 wt% for A, 20 wt% for B, 24 wt% for C
% To prepare liquid crystal compositions A6, B6, and C6. The liquid crystal composition A6 was around 680 nm, and the liquid crystal composition B6 was 56
The liquid crystal composition C6 is adjusted to selectively reflect light having a wavelength near 0 nm and a wavelength near 480 nm. Liquid crystal composition A
6, B6, and C6 have dielectric anisotropy Δε of 18,
13,8, and the refractive index anisotropy Δn is 0.21, 0.1.
4,0.14.

Next, a polyimide-based alignment control film AL4552 was formed on the transparent electrode forming surface of the PES (polyethersulfone) film on which the patterned transparent electrode was formed.
(Manufactured by JSR) was formed to a thickness of 800 angstroms and used as a first substrate. No rubbing treatment was performed on the orientation control film. Then, on the orientation control film forming surface of the first substrate,
A spacer of a predetermined size was sprayed. At the same time, an insulating film HIM3000 is formed to a thickness of 2000 Å on another PES film (second substrate) having a transparent electrode, and an orientation control film AL4552 is formed thereon to a thickness of 8 Å.
It was formed to 00 Å. No rubbing treatment was performed on the orientation control film. Subsequently, an ink containing a thermoplastic resin as a main component is placed on a metal mask having a large number of holes having a diameter of about 100 μm formed at intervals of about 500 μm on a second substrate, and screen printing is performed using a squeegee. Do
A columnar polymer structure having a height of 5 to 10 μm was formed.
Subsequently, a seal material XN21S was screen-printed on a peripheral portion on the first substrate to form a seal wall.

Thereafter, the liquid crystal composition A6 was applied on the first substrate, the first and second substrates were bonded using a bonding apparatus, and heated at 150 ° C. for 1 hour to obtain a liquid crystal display cell for red. Similarly, the first substrate and the second substrate were bonded using the liquid crystal compositions B6 and C6 to obtain green and blue liquid crystal display cells, respectively. Note that the liquid crystal composition A6 has a thickness of 9 μm.
, The liquid crystal composition B6 was filled in a cell having a thickness of 7 μm, and the liquid crystal composition C6 was filled in a cell having a thickness of 5 μm. These three
The types of cells were laminated in the order of blue, green, and red as viewed from the observation side, and a black light absorbing film was provided on the back surface of the laminate (the back surface of the cell containing the liquid crystal composition A6).

When each cell was driven in the same manner as in Experimental Example 1, the contrast of the laminated body was 6.5: 1 (W / B), showing extremely excellent display characteristics. The driving voltage was 55 V for each of the liquid crystal compositions A6, B6, and C6 when colored.
The voltage was 30 V when the color was erased.

(Experimental Example 4) The liquid crystal compositions A1, B1, and C1 shown in Experimental Example 1 were used. Then, three PES films (first substrate) having transparent electrodes were prepared, one of which was a red color filter film (manufactured by Fuji Film Olin) and the other was a yellow color filter film (Fuji Film Olin). Film Olin), and the remaining one is insulating film H
Each IM3000 was formed to a thickness of 2000 Å, and an orientation control film AL4552 was formed thereon to a thickness of 800 Å, and spacers of a predetermined size were sprayed. No rubbing treatment was performed on the orientation control film. On the other hand, an insulating film HIM3000 having a thickness of 20 was formed on three other PES films (second substrates) each having a transparent electrode.
The alignment control film AL4552 was formed thereon to a thickness of 800 Å. No rubbing treatment was performed on the orientation control film. Subsequently, an ink containing a thermoplastic resin as a main component is placed on a metal mask having a large number of holes having a diameter of about 100 μm formed at intervals of about 500 μm on a second substrate, and screen printing is performed using a squeegee. This was performed to form a columnar polymer structure having a height of 5 to 10 μm. Subsequently, a seal material XN21S was screen-printed on a peripheral portion on the first substrate to form a seal wall.

Thereafter, the liquid crystal composition A1 was coated on the first substrate, the first and second substrates were bonded using a bonding apparatus, and heated at 150 ° C. for 1 hour to obtain a liquid crystal display cell for red. Similarly, the first substrate and the second substrate were bonded using the liquid crystal compositions B1 and C1, to obtain green and blue liquid crystal display cells, respectively. The liquid crystal composition A1 has a thickness of 9 μm.
m, the liquid crystal composition B1 was filled in a cell having a thickness of 7 μm, and the liquid crystal composition C1 was filled in a cell having a thickness of 5 μm. These three types of cells were laminated in the order of blue, green, and red as viewed from the observation side, and a black light absorbing film was provided on the back surface of the laminate (the back surface of the cell containing the liquid crystal composition A1). .

When each cell was driven in the same manner as in Experimental Example 1, the contrast of the laminated body was 6: 1 (W / B), showing extremely excellent display characteristics. The driving voltage was 60 V for each of the liquid crystal compositions A1, B1, and C1 at the time of coloring, and 30 V at the time of decoloring.

(Experimental Example 5) With respect to the liquid crystal mixtures A, B and C shown in Experimental Example 1, A was 20 wt% of the chiral material CB15, B was 16 wt% of the chiral material S811,
C is the chiral material CM represented by the chemical formula (E ₉ )
31 (manufactured by Chisso Corporation) in an amount of 15 wt%, and a liquid crystal composition A
7, B7 and C7 were prepared. 680 n of the liquid crystal composition A7
m, the liquid crystal composition B7 is adjusted to selectively reflect light having a wavelength of about 560 nm, and the liquid crystal composition C7 is adjusted to selectively reflect light having a wavelength of about 480 nm. The dielectric anisotropy Δε of each of the liquid crystal compositions A7, B7, C7 was 17, 13, 13 and the refractive index anisotropy Δn was 0.18, 0.15, 0.15.

Next, a cell made of the same structure and material as in the above-mentioned Experimental Example 1 was manufactured by the same method, and the liquid crystal compositions A7, B7,
C7 was sealed to obtain red, green, and blue liquid crystal display cells. Note that the liquid crystal composition A7 was a cell having a thickness of 9 μm,
The cell of the liquid crystal composition B7 has a thickness of 7 μm and the liquid crystal composition C7.
Are cells having a thickness of 5 μm. These three types of cells are laminated in the order of blue, green, and red as viewed from the observation side, and the back surface of the laminate (the back surface of the cell containing the liquid crystal composition A7)
Was provided with a black light absorber.

When each cell was driven in the same manner as in Experimental Example 1, the contrast of the laminate was 5: 1 (W / B), showing extremely excellent display characteristics. The driving voltage was 60 V for each of the liquid crystal compositions A7, B7, and C7 during coloring and 30 V during erasing.

(Experimental Example 6) A liquid crystalline ester compound was added to 25
liquid crystal mixture H composed of an N-type tricyclic compound and an N-type bicyclic compound, the liquid crystal mixture H being composed of an N-type tricyclic compound and an N-type bicyclic compound, a liquid crystal phenylcyclohexane compound of 30 wt%, and a liquid crystal ester compound. 15wt
% Of a liquid crystal mixture I consisting of an N-type bicyclic compound, and 3 parts of a liquid crystalline cyanobiphenyl compound.
5 wt% and 16 wt% of a liquid crystalline tolan compound, and the remaining components are a liquid crystalline pyrimidine compound and N-type 2
14 wt%, 18 wt%, and 22 wt% of chiral material S811 (manufactured by Merck Japan Ltd.) were added to each of the liquid crystal mixtures J composed of a ring compound, and a liquid crystal composition H1 having a selective reflection wavelength of about 680 nm and a liquid crystal composition H1 of about 56, respectively.
0 nm liquid crystal composition I1, about 480 nm liquid crystal composition J
1 was prepared. The dielectric anisotropies of the liquid crystal compositions H1, I1, and J1 were 20, 12, and 7, respectively. Further, their refractive index anisotropy is 0.21, 0.14, 0.1, respectively.
It was 4.

Next, three PESs on which transparent electrodes were formed were formed.
0.3μm and 0.25μ respectively on the film substrate
An insulating film HIM3000 (manufactured by Hitachi Chemical Co., Ltd.) having a thickness of 0.2 μm was formed. Further thereon, an orientation control film AL4552 (manufactured by JSR Corporation) having a thickness of 800 Å was formed. No rubbing treatment was performed on the orientation control film. Subsequently, spacers having a particle size of about 7 μm were sprayed on the orientation control films of these substrates.

Further, three PESs on which transparent electrodes were formed were used.
On the transparent electrode of the film substrate, an alignment control film AL4552 having a thickness of 800 Å was formed.
No rubbing treatment was performed on the orientation control film. And
On the orientation control film of these substrates, a resin material mainly composed of a thermoplastic resin is formed with a hole having a diameter of about 100 μm of about 500 μm.
It is placed on a metal mask formed at intervals of m and screen-printed by extruding with a squeegee.
m of a columnar polymer structure was formed.

After that, the liquid crystal composition H1 was supplied to the polymer structure forming surface of the substrate placed on the flat plate, and the thickness was set to 0.3.
The substrate on which the insulating film having a thickness of μm was formed was adhered using a pressure roller while being bent, and heated at 150 ° C. for 1 hour to produce a liquid crystal display layer for red. Similarly, a liquid crystal display layer for green was manufactured using the liquid crystal composition I1 and a substrate on which an insulating film having a thickness of 0.25 μm was formed.
A liquid crystal display layer for blue was manufactured using the substrate on which the m insulating film was formed.

When a pulse voltage of 60 V is applied, all of the three liquid crystal display layers thus produced become colored.
When a pulse voltage of 30 V was applied, the film became transparent. Each of these liquid crystal display layers is laminated in the order of blue, green, and red from the observation side, and a light absorbing layer that absorbs visible light is provided on a surface of the red liquid crystal display layer opposite to the observation side. By
A multi-layer liquid crystal display device capable of full color display was obtained. The contrast ratio of this multi-layer liquid crystal display element was a very high value of 5: 1 (white / black).

(Experimental Example 7) 15% by weight of a liquid crystalline phenylcyclohexane compound having an alkyl chain having 4 carbon atoms
A liquid crystal mixture D containing 10 wt% of a liquid crystalline phenylcyclohexane compound having an alkyl chain having 5 carbon atoms and 15 wt% of a liquid crystalline phenylcyclohexane compound having an alkyl chain having 5 carbon atoms and having a carbon number of 5 wt%. Liquid crystal mixture E containing 10 wt% of a liquid crystalline phenylcyclohexane compound having an alkyl chain of 6
And a liquid crystal mixture F containing 15 wt% of a liquid crystalline phenylcyclohexane compound having an alkyl chain having 6 carbon atoms and 10 wt% of a liquid crystalline phenylcyclohexane compound having an alkyl chain having 7 carbon atoms,
Liquid crystal compositions D1, E1, and F1 were prepared by adding a predetermined amount of chiral material S811, that is, 16 wt% to D, 18 wt% to E, and 20 wt% to F. The liquid crystal composition D1 was around 680 nm, and the liquid crystal composition E1 was 560 nm.
m, the liquid crystal composition E1 is adjusted to selectively reflect light having a wavelength near 480 nm. Liquid crystal compositions D1, E
The dielectric anisotropy Δε of each of F1, F1 is 13, 12,
11, and the refractive index anisotropy Δn is 0.17, 0.16,
0.15. The remaining components of the liquid crystal mixtures D, E, and F consist of a liquid crystalline pyrimidine compound and an N-type bicyclic compound.

Next, a cell made of the same structure and material as in the above-mentioned Experimental Example 3 was manufactured by the same method, and the liquid crystal compositions D1, E1,
F1 was sealed to obtain liquid crystal display cells for red, green, and blue. The cell of the liquid crystal composition D1 had a thickness of 9 μm,
The cell of the liquid crystal composition E1 has a thickness of 7 μm, and the cell of the liquid crystal composition has a thickness of 5 μm. These three types of cells were laminated in the order of blue, green, and red as viewed from the observation side, and a black light absorbing film was provided on the back surface of the laminate (the back surface of the cell containing the liquid crystal composition D1). .

When each cell was driven in the same manner as in Experimental Example 1, the contrast of the laminate was 5: 1 (W / B), showing extremely excellent display characteristics. The driving voltage was 70 V for each of the liquid crystal compositions D1, E1, and F1 when colored, and 40 V when decolored.

(Experimental Example 8) 15% by weight of a liquid crystalline phenylcyclohexane compound having an alkyl chain having 4 carbon atoms
A chiral material for a liquid crystal mixture G containing 10 wt% of a liquid crystalline phenylcyclohexane compound having an alkyl chain having 6 carbon atoms and the remaining components being a P-type tricyclic compound and an N-type bicyclic compound. Liquid crystal composition G1 containing 20 wt% of CB15, chiral material S81
Liquid crystal composition G2 containing 16 wt% of No. 1 and chiral material C
Liquid crystal composition G3 to which N (manufactured by Merck Japan) was added at 18 wt% was prepared. The liquid crystal composition G1 was around 680 nm, the liquid crystal composition G2 was around 560 nm, and the liquid crystal composition G3
Is adjusted to selectively reflect light having a wavelength near 480 nm. The dielectric anisotropy Δε of each of the liquid crystal compositions G1, G2, and G3 was 13, 12, 11, and the refractive index anisotropy Δn was 0.18, 0.16, and 0.16.

Next, a cell made of the same structure and material as in the above-mentioned Experimental Example 3 was manufactured by the same method, and the liquid crystal compositions G1, G2,
G3 was sealed to obtain liquid crystal display cells for red, green, and blue. The cell of the liquid crystal composition G1 has a thickness of 9 μm,
The cell of the liquid crystal composition G2 has a thickness of 7 μm and the liquid crystal composition G3.
Has a thickness of 5 μm. These three types of cells were laminated in the order of blue, green, and red as viewed from the observation side, and a black light absorbing film was provided on the back surface of the laminate (the back surface of the cell containing the liquid crystal composition G1). .

When each cell was driven in the same manner as in Experimental Example 1, the contrast of the laminated body was 5: 1 (W / B), showing extremely excellent display characteristics. The driving voltage was 75 V for each of the liquid crystal compositions G1, G2, and G3 when coloring, and 40 V when decoloring.

(Experimental Example 9) In Experimental Example 9, a liquid crystal display device having a two-layer structure shown in FIG. 5 was constructed. For the liquid crystal mixtures A and B shown in Experimental Example 1, dichroic dyes SI-426 and M570 (manufactured by Mitsui Chemicals, Inc.) that absorb light in the wavelength range of R and B, respectively, were used. 2w
The liquid crystal compositions A8 and B8 were prepared by adding t% each. The liquid crystal composition A8 was around 680 nm, and the liquid crystal composition B8 was 48 nm.
It is adjusted to absorb light having a wavelength near 0 nm. Dielectric anisotropy Δ of each of liquid crystal compositions A8 and B8
ε is 20, 15, and the refractive index anisotropy Δn is 0.22,
0.15.

Next, a polyimide-based orientation control film AL4552 (manufactured by JSR Corporation) was formed to a thickness of 800 angstroms on the transparent electrode forming surface of the PES film on which the patterned transparent electrode was formed, and used as a first substrate. Then, spacers of a predetermined size were sprayed on the orientation control film forming surface of the first substrate. At the same time, an insulating film HIM3 is formed on another PES film (second substrate) with a patterned transparent electrode.
Was formed to a thickness of 2000 angstroms, and a polyimide-based orientation control film AL4552 was formed thereon to a thickness of 800 angstroms. Subsequently, a sealing material XN21S is screen-printed on a peripheral portion on the first substrate,
A seal wall having a predetermined height was formed except for the injection port of the liquid crystal composition. Then, the first and second substrates were bonded together and heated at 150 ° C. for 1 hour while applying a predetermined pressure to produce two cells.

Next, each of the liquid crystal compositions A8 and B8 was filled into each cell from the injection port by a vacuum injection method to obtain red and blue liquid crystal display cells. The cell of the liquid crystal composition A8 has a thickness of 7 μm, and the cell of the liquid crystal composition B8 has a thickness of 5 μm. These two types of cells were laminated in the order of blue and red as viewed from the observer side, and a black light absorbing film was provided on the back surface of the laminate (the back surface of the cell containing the liquid crystal composition A8).

When each cell was driven, the contrast of the laminate was 4: 1, and the display characteristics (red on a blue background) were good when each was colored simultaneously. The driving voltage was 3 V when coloring each of the liquid crystal compositions A8 and B8, and 0 V (no voltage was applied) when decoloring.

(Experimental Example 10) A liquid crystal mixture J containing 35% by weight of a liquid crystalline cyanobiphenyl compound and 16% by weight of a liquid crystalline tolane compound as used in Experimental Example 6 above.
15 wt%, 18 wt%, and 22 wt% of chiral material S811 (manufactured by Merck Japan Ltd.), respectively, and a liquid crystal composition J2 having a selective reflection wavelength of about 680 nm, a liquid crystal composition J3 of about 560 nm, and about 480 nm.
Was prepared. Liquid crystal compositions J2, J3,
The dielectric anisotropy Δε of J4 was 11, 9, 7 respectively. Further, their refractive index anisotropy Δn is 0.2
1,0.17,0.14.

In the experimental example 6, the liquid crystal composition H
1, I1, J1 instead of liquid crystal compositions J2, J
3, except for using J4, in the same manner as in Experimental Example 6, for red
Three liquid crystal display cells for green and blue were produced, and a multilayer liquid crystal display element was obtained.

As a result, the contrast ratio of the liquid crystal display device was a low value of 2: 1 (white / black). The red display layer becomes colored when a pulse voltage of 80 V is applied,
When a pulse voltage of 45 V was applied, the film became transparent. The green display layer became colored when a pulse voltage of 85 V was applied, and became transparent when a pulse voltage of 50 V was applied. The blue display layer became colored when a pulse voltage of 90 V was applied, and became transparent when a pulse voltage of 55 V was applied.

(Experimental Example 11)
wt%, 10w of liquid crystalline phenylcyclohexane compound
The chiral material S-811 (manufactured by Merck Japan Ltd.) is contained in a predetermined amount, that is, 17 wt% with respect to the liquid crystal mixture L containing the liquid crystalline pyrimidine compound and the N-type bicyclic compound while the remaining components are contained. , 22 wt%, 2
Liquid crystal compositions L1, L2, and L3 to which 6 wt% was added were prepared. The liquid crystal composition L1 was around 680 nm, and L2 was 560n.
m and L3 are adjusted so as to selectively reflect light having a wavelength of around 480 nm. Liquid crystal compositions L1, L2, L3
Have dielectric anisotropy Δε of 12, 10, 8, respectively.
The refractive index anisotropy Δn was 0.2, 0.18, 0.16.

Next, three PESs on which transparent electrodes were formed were formed.
An 800 angstrom thick alignment film AL4552 (manufactured by JSR) is formed on a transparent electrode of a film substrate, and a 7 μm diameter spacer (manufactured by Sekisui Fine Chemical) is formed thereon.
Was sprayed. Further, an insulating film HIM3000 (manufactured by Hitachi Chemical Co., Ltd.) having a thickness of 2000 angstroms is first formed on the transparent electrodes on the other three PES film substrates with a transparent electrode, and then an orientation film AL4552 having a thickness of 800 angstroms is formed thereon. Was formed. Subsequently, a sealing material XN21S (manufactured by Mitsui Chemicals, Inc.) was screen-printed around the first substrate to form a sealing wall.

Thereafter, the liquid crystal compositions L1, L2, and L3 were applied on the respective first substrates, and the first and second substrates were bonded using a bonding apparatus, and heated at 150 ° C. for one hour to obtain a red color composition. Thus, liquid crystal display cells for green and blue were obtained. These three types of cells were laminated in the order of red, green, and blue as viewed from the observation side, and a black light absorbing layer was provided on the back surface of the laminate to obtain a laminated liquid crystal display device.

When each cell was driven at a predetermined voltage to bring it into a colored state and a decolored state, the contrast of the laminate was 2: 1 (W / B). It became.

The driving voltage of the liquid crystal composition A1 was 85 V / 55 V for coloring / decoloring, and the driving voltage was 90 V / 60 for coloring / decoloring A2.
For V and A3, coloring / decoloring was 95 V / 65 V.

(Other Embodiments) The liquid crystal light modulation device according to the present invention is not limited to the above embodiments and experimental examples, but can be variously modified within the scope of the gist.
In particular, specific examples and numerical values of various materials such as a liquid crystal are merely examples. Further, there are various driving methods of the display element,
The best one may be adopted.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a first example of a cell constituting the liquid crystal display element.

FIG. 3 is a sectional view showing a second example of a cell constituting the liquid crystal display element.

FIG. 4 is a sectional view showing a third example of a cell constituting the liquid crystal display element.

FIG. 5 is a sectional view showing a liquid crystal display element according to a second embodiment of the present invention.

FIG. 6 is a plan view showing a state in which a columnar structure and a sealing material are formed on a film substrate constituting a cell.

FIG. 7 is an explanatory view showing a manufacturing process of the cell.

FIG. 8 is a block diagram showing a matrix drive circuit of the liquid crystal display element.

FIG. 9 is a graph showing a relationship between a voltage applied to a selection signal and a Y value in the matrix driving circuit.

FIG. 10 is a block diagram showing a driving / image signal processing circuit of the liquid crystal display element.

[Explanation of symbols]

 10, 40 liquid crystal display elements 11R, 11G, 11B, 41X, 41Y display layer 17 liquid crystal composition 21 spacer 22 polymer structure 23 network polymer matrix 110B, 110G, 110R liquid crystal display cell

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hideaki Ueda 2-13-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka International Building Minolta Co., Ltd. 2H089 HA04 HA09 HA23 JA04 JA05 KA08 LA07 LA09 LA19 MA04Y MA07X NA13 NA14 NA25 NA41 QA04 QA14 QA16 RA06 SA01 SA03 TA01 TA04 TA05 TA06 TA12 TA13

Claims (26)

[Claims] 1. A liquid crystal light modulating element in which a plurality of liquid crystal layers each containing a liquid crystal composition are laminated, and each liquid crystal layer modulates light in a specific wavelength range, wherein the composition type of the liquid crystal composition contained in the liquid crystal layer is A liquid crystal light modulation device, wherein each liquid crystal layer is different. 2. A liquid crystal light modulation device in which a plurality of liquid crystal layers each containing a liquid crystal composition are laminated, and each liquid crystal layer modulates light in a specific wavelength range, wherein the plurality of liquid crystal layers are included in the liquid crystal layer. A liquid crystal light modulation device comprising at least two liquid crystal layers having different composition types and different thicknesses of the liquid crystal composition. 3. The plurality of liquid crystal layers include a set of liquid crystal layers having different thicknesses from each other and a liquid crystal composition contained in the thicker layer having a larger dielectric anisotropy than the other. 3. The liquid crystal light modulation device according to claim 2, wherein: 4. The liquid crystal composition contained in a liquid crystal layer having a larger dielectric anisotropy of the liquid crystal composition than the other liquid crystal composition contains a liquid crystal compound having a polar group. The liquid crystal light modulation device as described in the above. 5. The liquid crystalline compound having a polar group includes a liquid crystalline ester compound, a liquid crystalline pyrimidine compound,
The liquid crystal composition according to claim 4, comprising at least one liquid crystal compound selected from the group consisting of a liquid crystal cyanobiphenyl compound, a liquid crystal cyanophenylcyclohexane compound, a liquid crystal cyanoterphenyl compound, and a liquid crystal difluorostilbene compound. Liquid crystal light modulator. 6. The liquid crystal light modulation device according to claim 2, wherein the thicknesses of the plurality of liquid crystal layers are all different. 7. The liquid crystal composition contained in each of the liquid crystal layers has a different dielectric anisotropy from each other. The liquid crystal light modulation device as described in the above. 8. A liquid crystal light modulation device in which a plurality of liquid crystal layers each containing a liquid crystal composition are laminated, and each liquid crystal layer modulates light in a specific wavelength range, wherein the plurality of liquid crystal layers are included in the liquid crystal layer. A liquid crystal light modulation device comprising at least two liquid crystal layers having different types of liquid crystal compositions and equal driving voltage ranges. 9. The liquid crystal light modulation device according to claim 8, wherein the drive voltage ranges of the plurality of liquid crystal layers are all equal. 10. The liquid crystal composition of each liquid crystal layer, wherein the composition type of each liquid crystal layer is different for each liquid crystal layer. 10. The liquid crystal light modulation element according to claim 7, claim 8, or claim 9. 11. The liquid crystal composition contained in each of the liquid crystal layers contains a liquid crystal compound and an additive. The liquid crystal light modulation device according to claim 6, claim 7, claim 8, claim 9, or claim 10. 12. The liquid crystal composition of one liquid crystal layer, wherein the kind of liquid crystal compound contained in the liquid crystal composition is different from the kind of liquid crystal compound contained in another liquid crystal layer.
2. The liquid crystal light modulation device according to 1. 13. The liquid crystal light according to claim 11, wherein the kind of the additive contained in the liquid crystal composition of one liquid crystal layer is different from the kind of the additive contained in the other liquid crystal layer. Modulation element. 14. The method according to claim 11, wherein the additive comprises a compound having at least one asymmetric carbon.
The liquid crystal light modulation device according to claim 12. 15. The liquid crystal layer according to claim 1, wherein the liquid crystal layer is switchable between a selective reflection state and a transmission state.
Claim 2, Claim 3, Claim 4, Claim 5, Claim 6,
Claim 7, Claim 8, Claim 9, Claim 10, Claim 1
The liquid crystal light modulation device according to claim 1, claim 12, 13 or 14. 16. The liquid crystal composition according to claim 1, wherein the liquid crystal composition exhibits a cholesteric phase at room temperature. Claim 8, Claim 9, Claim 10, Claim 11, Claim 1
The liquid crystal light modulation device according to claim 2, claim 13, 14, or 15. 17. A liquid crystal layer for displaying blue, a liquid crystal layer for displaying green, and a liquid crystal layer for displaying red, wherein the plurality of liquid crystal layers are sequentially stacked from a light incident side.
17. The liquid crystal light modulation device according to claim 16, comprising a layer. 18. The liquid crystal layer according to claim 1, wherein said liquid crystal layer is switchable between a state of absorbing light in a specific wavelength range and a transmitting state. 13. The liquid crystal light modulation device according to claim 5, claim 6, claim 7, claim 8, claim 9, claim 10, claim 11, or claim 12. 19. The liquid crystal device according to claim 1, wherein each of the liquid crystal layers performs display by a guest-host effect.
Claim 3, Claim 4, Claim 5, Claim 6, Claim 7,
13. The liquid crystal light modulation device according to claim 8, claim 9, 9, 10, 11, or 12. 20. The liquid crystal light modulation device according to claim 11, wherein the additive is a polychromatic dye. 21. The color filter according to claim 1, wherein a color filter is arranged between at least one pair of adjacent liquid crystal layers. Claim 7, Claim 8, Claim 9, Claim 10, Claim 11, Claim 12, Claim 13, Claim 14, Claim 15, Claim 16, Claim 17, Claim 18, Claim The liquid crystal light modulation device according to claim 19 or 20. 22. The liquid crystal layer according to claim 1, wherein each of the liquid crystal layers is sandwiched between a pair of substrates. , Claim 7, Claim 8, Claim 9, Claim 10, Claim 11, Claim 12, Claim 13, Claim 14, Claim 15, Claim 16, Claim 17, Claim 18, Claim 22. The liquid crystal light modulation device according to claim 19, 20 or 21. 23. The liquid crystal light modulation device according to claim 22, wherein at least one of the pair of substrates has flexibility. 24. The liquid crystal light modulation device according to claim 22, wherein a resin structure is disposed in a light modulation region between the pair of substrates. 25. The liquid crystal display device according to claim 1, wherein each of the liquid crystal layers is a composite film in which the liquid crystal composition is dispersed in a network polymer matrix. , Claim 5, Claim 6, Claim 7, Claim 8, Claim 9, Claim 10, Claim 11, Claim 12, Claim 1
3, Claim 14, Claim 15, Claim 16, Claim 1
7, Claim 18, Claim 19, Claim 20, Claim 2
24. The liquid crystal light modulation device according to claim 22. 26. The liquid crystal display device according to claim 22, wherein a functional thin film is provided on at least one of the pair of substrates, and the thickness of the functional thin film is equal for each liquid crystal layer. Item 25. A liquid crystal light modulation device according to item 24.