JPH06230371A - Reflection type liquid crystal electrooptical device - Google Patents

Abstract

PURPOSE:To provide the reflection type liquid crystal electrooptical device which is practicable and can make bright and highly aesthetic color display by providing a reflection plate made of a cholesteric liquid crystal polymer exhibiting a selective reflection characteristic in a visible light region. CONSTITUTION:The reflection plate 9 made of the cholesteric liquid crystal polymer selectively reflects the light of the left-hand (right-hand) polarized light which is is the same in the pitch of the spiral structure of a cholesteric liquid crystal structure and the direction of the spiral axis of the wavelength band corresponding to the average refractive index in accordance with the nature of the cholesteric liquid crystal structure. The transmitted light 23 is mostly absorbed by a black plate and, therefore, the reflected light is made into reflected light 22 of the colored light by only the corresponding wavelength band if an light absorption plate 10 is a black plate. The reflected light 24 of a specific wavelength is emitted as well if the light absorption plate 10 reflects the light of only the specific wavelength. The synthesized light of the reflected light 22 and the reflected light 24 is, therefore, eventually observed and the color tones are delicately changed by changing the reflection characteristics of the light reflection plate 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective liquid crystal electro-optical device, and more particularly to a color reflective liquid crystal electro-optical device for displaying a bright and aesthetically pleasing color tone used in watches and small portable devices.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, a conventional reflective liquid crystal electro-optical device for displaying black and white has electrodes 3 and 3'on two substrates 2 and 2'which face each other. The liquid crystal layer 5 is provided in the space between the substrates via the spacer 14 between the substrates, and the reflector 15 is provided behind the liquid crystal element for the observer 17. Further, if necessary, polarizing plates 1 and 1 '
Are arranged as shown in the figure. Reflectors that are commonly used are processed by sandblasting a metal surface such as aluminum in order to widen the viewing angle, or give appropriate light diffusion,
Alternatively, a metal plate such as aluminum is vapor-deposited after forming irregularities on the substrate surface of the reflection plate to form the reflection plate. On the other hand, for colorization, a color filter 16 is provided in front of the reflector 15.
Is provided to enable color display. As the color filter 16, a transparent resin film whose surface is coated with a dye or a product produced by dissolving a dye in a transparent resin is used. Further, without using the color filter 16, a method that enables color display by using a color polarizing plate for at least one of the polarizing plates 1 and 1 ', or a dye is provided on the metal surface of the reflecting plate 15. There is a method of coating or printing to enable color display as a colored reflector, or a method of coating several layers of dielectric on the substrate surface of the reflector 15 to enable color display as a dichroic mirror. Further, a system has been proposed in which a color reflective plate function is provided by using, instead of the reflective plate 15, a cholesteric liquid crystal cell that exhibits selective reflectivity at a specific wavelength in the visible light region.

[0003]

However, the color display system in which a color filter, which has been widely used in the past, and a reflection plate such as aluminum are combined, has a transmittance of a dye used in the color filter and a metal reflection plate such as aluminum. Due to the poor reflectance, clear color display is impossible. Further, the color display method using a dichroic mirror with a dielectric coating has a high linear reflectance after reflection and a low diffuse reflectance, so that the contrast between the display section and the non-display section is low, and it is difficult to distinguish the display. In addition, a vacuum process is required for the dielectric coating, and the manufacturing cost is high. Further, in the system using the cholesteric liquid crystal cell as the color reflector, the change of the reflection wavelength with the temperature change of the cholesteric pitch is large, and the temperature region showing the selective reflection is narrow. In addition, since the cholesteric liquid crystal is a low molecular weight liquid crystal, it is necessary to have a structure in which it is injected into the gap between two glass substrates, so that the distance between the liquid crystal optical element and the reflection plate becomes large, and a shadow is generated to make the visibility easier. Deteriorate. Further, there is a problem in that it is difficult to obtain a reflective liquid crystal electro-optical device that is practical, vivid and excellent in color display and has a drawback that it cannot be manufactured at a low cost due to its structure.

Therefore, in order to solve such a conventional problem, an object of the present invention is to provide a cholesteric liquid crystal polymer reflector having a selective reflection property in a visible light region to provide a practical, clear and aesthetically pleasing color. It is to obtain a displayable reflective liquid crystal electro-optical device.

[0005]

In order to solve the above problems, the present invention provides a cholesteric liquid crystal polymer having a selective reflection property in the visible light region between a liquid crystal display device and a light absorbing plate having absorption in the visible light region. The problem is solved by a reflection type liquid crystal electro-optical device configured to have a reflection plate.

[0006]

The operation principle of the reflection type liquid crystal display device constructed as described above will be described with reference to FIG.
In the figure, 6 is a liquid crystal display element, 9 is a cholesteric liquid crystal polymer reflection plate, 10 is a light absorption plate, 21 is incident white light, 22
Is reflected light, and 23 is transmitted light.

In the figure, the incident white light 21 that has entered the liquid crystal display element 6 undergoes two-dimensional light modulation by the display information, passes through the liquid crystal display element 6, and then enters the cholesteric liquid crystal polymer reflector 9. Here, the cholesteric liquid crystal polymer reflector 9 is a polymer in which a cholesteric liquid crystal structure of a polypeptide such as polyglutamate is heated at a specific temperature and then rapidly cooled to fix the cholesteric structure, and based on the properties of the cholesteric liquid crystal structure. If the pitch P of the spiral structure, the average refractive index n, and the anisotropy of the refractive index are Δn, the central wavelength λ0 is λ0 when the incident light is perpendicular to the spiral axis.
= N · P, the wavelength width Δλ selectively reflects right circularly polarized light or left circularly polarized light having the same spiral axis direction in the wavelength band corresponding to Δλ = Δn · P. When the light absorbing plate 10 is a black plate, the reflected light from the cholesteric liquid crystal polymer reflecting plate 9 is the right circularly polarized light component of the wavelength band Δλ at the central wavelength λ 0 because the transmitted light 23 is mostly absorbed by the black plate, or It becomes colored light only by the left-handed circularly polarized light component, and again becomes colored reflected light 22 which passes through almost the same place of the liquid crystal display element 6. The light absorbing plate 10 reflects only light of a specific wavelength. That is, when it has a specific color, the reflected light 24 having a specific wavelength also passes through the cholesteric liquid crystal polymer reflector 9 and the liquid crystal display element 6 and is emitted. Therefore, the combined light of the reflected light 22 and the reflected light 24 is observed, and the color tone can be delicately changed by changing the reflection characteristic of the light absorption plate 10.

In this way, when the light absorbing plate is a black plate, the spiral pitch and the average refractive index of the cholesteric liquid crystal polymer reflecting plate 9 are appropriately changed to obtain an arbitrary monocolor and an appropriate refractive index anisotropy. A high-purity monocolor can be displayed by setting the value to any value, and the color tone can be delicately changed by changing the reflection characteristic of the light absorbing plate.

Further, when the incident light is displaced from the spiral axis direction, λ0 and Δλ slightly change depending on the incident angle. That is, the display color slightly changes depending on the viewing angle direction, and exhibits a so-called cholesteric color. This cholesteric color is a so-called iridescent color that can be seen in the insect beetle in nature, and shows a very noble and beautiful unique shade.

Further, since the cholesteric liquid crystal polymer reflection plate 9 has a fixed cholesteric structure, the spiral pitch does not change due to temperature changes, so that there is no temperature change in the central wavelength and stable color display is possible. Is. In the case where the liquid crystal display element 6 has a polarizing plate, the incident white light incident on the liquid crystal display element 6 becomes linearly polarized light when emitted from the liquid crystal display element 6, and the circularly polarized light selective reflection efficiency at the cholesteric liquid crystal polymer reflector 9 is increased. Is reduced.
In order to improve this, a quarter-wave plate that changes the phase of light by 90 degrees at the selective reflection center wavelength λ 0 of the cholesteric liquid crystal polymer reflector 9 is inserted between the liquid crystal display element 6 and the cholesteric liquid crystal polymer reflector 9. By making the linearly polarized light circularly polarized light in the same rotation direction as the rotation direction of the spiral axis of the cholesteric liquid crystal polymer reflection plate 9, the reflectance can be increased to nearly 100% at the selective reflection center wavelength λ 0, and clear visibility is obtained. Good display of

In the case where the liquid crystal display element 6 does not have a polarizing plate, the incident white light incident on the liquid crystal display element 6 includes a part of non-polarized light when emitted from the liquid crystal display element 6, and thus the cholesteric liquid crystal polymer reflector. The circularly polarized light selective reflection efficiency at 9 decreases. In order to improve this, the structure of the cholesteric liquid crystal polymer reflection plate 9 is formed by stacking a cholesteric liquid crystal polymer that reflects right-handed circularly polarized light of a specific wavelength and a cholesteric liquid crystal polymer that reflects left-handed circularly polarized light with their optical axes parallel to each other. According to the configuration, the liquid crystal display element 6
Light including a part of non-polarized light emitted from is reflected by the cholesteric liquid crystal polymer reflection plate 9 of this configuration by being divided into a right-handed circularly polarized light component and a left-handed circularly polarized light component, and the reflectance is increased to nearly 100% at the selective reflection center wavelength λ 0 It is possible to do a clear display with good visibility.

Similarly, in the case where the liquid crystal display element 6 does not have a polarizing plate, the incident white light incident on the liquid crystal display element 6 includes a part of non-polarized light when it is emitted from the liquid crystal display element 6, and the cholesteric liquid crystal polymer reflection occurs. The circularly polarized light selective reflection efficiency at the plate 9 is reduced. In order to improve this, the structure of the cholesteric liquid crystal polymer reflection plate 9 is such that the phase of light of the specific wavelength is set between two cholesteric liquid crystal polymers that selectively reflect circularly polarized light of the same rotation direction of the specific wavelength. 180
By having a structure in which a wavelength plate for converting the wavelength is sandwiched, the light including a part of non-polarized light emitted from the liquid crystal display element 6 is right-circularly polarized by the cholesteric liquid crystal polymer reflection plate 9 of this structure. The component and the left-handed circularly polarized component are reflected separately, and the reflectance can be increased to nearly 100% at the selective reflection center wavelength λ 0, and a clear display with good visibility can be performed.

Further, since the liquid crystal display element 6, the cholesteric liquid crystal polymer reflection plate 9 and the light absorption plate 10 are separated by an air layer from each other, a laminated structure of an adhesive or an adhesive is applied to each interface. By reducing the Fresnel reflection of the, it enables a bright and highly visible display.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. (Example 1) In FIG. 1, the transparent substrates 2 and 2'use smooth glass plates, but transparent polymer films may also be used. Transparent electrodes 3 provided on transparent substrates 2 and 2 '
In 3 and 3 ′, a transparent conductive film made of an ITO film was divided and formed by photolithography. Then, on the transparent electrodes 3 and 3 ', for example, a film having a film thickness of several tens of nm such as holimide or polyvinyl alcohol is applied and treated so that the rubbing direction is about 90 degrees to form the alignment films 4 and 4'. After the formation, a nematic liquid crystal having a positive dielectric anisotropy was injected with a cell gap of about 6 μm. The polarizing plates 1 and 1'were laminated so that their absorption axes were orthogonal to each other, and a so-called 90-degree twisted nematic liquid crystal display element 6 was produced. As the liquid crystal display device 6 using a polarizing plate, an operation mode such as a guest-host system, a birefringence control system, a supertwist nematic birefringence system, a ferroelectric liquid crystal system, etc. can be used in addition to the 90-degree twist nematic system.

The liquid crystal display element 6 thus produced is adhered to the surface of the polarizing plate 1'side by an ester type optical adhesive or a pressure sensitive adhesive made of a copolymer of butyl acrylate and 2 ethylhexyl acrylate with an acrylic monomer. A quarter wave plate 8 coated with layers 7 and 7'was attached. The directions of the optical axes at the time of bonding are so aligned that the incident light 21 is converted into the linearly polarized light emitted from the polarizing plate 1 ′ of the liquid crystal display element 6 into the circularly polarized light.
The quarter-wave plate 8 is made of a uniaxially stretched polycarbonate film and has a retardation Δnd of 133 nm. The adhesive layers 7 and 7'can be used as long as they are transparent adhesives and pressure-sensitive adhesives, and also have a function of reducing Fresnel reflection at each interface. 1
The / 4 wave plate 8 can be made of a polymer film such as polystyrene or an optical crystal such as a crystal flake or calcite in addition to polycarbonate.

Further, after forming the cholesteric liquid crystal polymer layer reflection plate 9 on the light absorption plate 10, it was laminated via the adhesive layer 7 '. As the light absorption plate 10, a black plate was used which was dyed in black so as to have absorption in the visible light region in a methacrylic resin having a thickness of 0.5 mm. The cholesteric liquid crystal polymer reflector 9 is made by sandwiching a polymer having a cholesteric liquid crystal structure of a polypeptide such as polyglutamate between polyethylene terephthalate films and rapidly cooling it from a heated state at a specific temperature after sealing. Center wavelength λ 0 is 530 nm, wavelength band Δλ is 70 n
m and maximum reflectance of 48% (non-polarization measurement condition) were used. Here, the black plate 10 may be a polymer film, a substrate, or a metal plate other than methacrylic resin that is dyed in black. Also, the cholesteric liquid crystal polymer reflector 9
Is a lyotropic cholesteric liquid crystal using a photopolymerizable unsaturated monomer as a solvent to form a cholesteric structure,
It is also possible to use those having a cholesteric structure immobilized by photopolymerization later. Further, the light absorption plate 10 and the cholesteric liquid crystal polymer reflection plate 9 may be laminated and integrated by press heating.

When the reflection type liquid crystal electro-optical device manufactured in this way is observed under the condition of normal incidence of white light, A in FIG.
In the area where the drive voltage is not applied like the area,
The incident light 21 was observed as a reflected light 22 with a bright green color. When measured with a spectrophotometer, a reflection spectrum as shown in FIG. 6 was obtained. On the other hand, in the region B to which the drive voltage is applied, the incident light 21 'is hardly observed as the reflected light 22', and a black display is presented.

Next, when this reflection type liquid crystal electro-optical device was mounted on a wrist watch and observed, it became a deep black display on a clear green background, and was brighter and more visible than a color display by a color filter. It was Furthermore, the green color changes subtly depending on the viewing angle, showing a so-called iridescent, noble and beautiful unique hue, which significantly improves the aesthetic or artistic added value of the digital wristwatch. Further, when the temperature was observed in the range of -20 ° C to 90 ° C, the green display hardly changed, which satisfied the actual operating environment conditions of the wristwatch.

In addition, it is added that when the polarizing plates 1 and 1'are made into parallel Nicols (normally black), a clear green display can be made on a deep black background. (Embodiment 2) In FIG. 3, the transparent substrates 2 and 2'use smooth glass plates, but transparent polymer films may be used. An antireflection film 11 was coated on the incident surface side of the transparent substrate 2 in order to reduce surface reflection in the visible light region. The transparent electrodes 3 and 3 ′ provided on the transparent substrates 2 and 2 ′ are formed by dividing a transparent conductive film made of an ITO film by photolithography. Then, on the transparent electrodes 3 and 3 ′, for example, a polyimide vertical aligning agent having a film thickness of several tens of nm is applied as a film and subjected to a baking treatment to obtain alignment films 4 and 4 ′.
After forming the film, the nematic liquid crystal with positive dielectric anisotropy and a black anthraquinone-based compound 2 with a cell gap of about 9 μm was used.
ZLI-8 as a chiral agent after dissolving 2% by weight of a color dye
11 (manufactured by Merck & Co., Inc.) was heated and mixed at 2% by weight and then injected to prepare a so-called cholesteric / nematic phase transition guest / host type liquid crystal display element 6. In addition to this, as the liquid crystal display element 6 which does not use a polarizing plate, an operation mode such as a nematic cholesteric phase transition type guest-host system or a polymer dispersion type guest-host system can be used.

The liquid crystal display element 6 thus produced is adhered to the surface of the transparent substrate 2'side by an ester type optical adhesive or a pressure sensitive adhesive composed of a copolymer of butyl acrylate and 2 ethylhexyl acrylate with an acrylic monomer. The transparent support substrate 1 is provided on the light absorption plate 10 through the layer 7.
The cholesteric liquid crystal polymers sandwiched between 2 and 12 'were laminated in a laminated state. The adhesive layer 7 can be used as long as it is a transparent adhesive or pressure-sensitive adhesive, and also has a function of reducing Fresnel reflection at each interface.

The light absorbing plate 10 was a blackboard plate which was dyed in black so as to have absorption in the visible light region with a methacrylic resin. The cholesteric liquid crystal polymer is a polymer having a cholesteric liquid crystal structure of a polypeptide such as polyglutamate which selectively reflects right-handed circularly polarized light of a specific wavelength and a left-handed circularly polarized light of the specific wavelength between transparent supporting substrates 12 and 12 'of polyethylene terephthalate film. A polymer with a cholesteric liquid crystal structure of a polypeptide such as polyglutamate that selectively reflects is sandwiched and rapidly cooled from a heated state at a specific temperature after sealing. The thickness is about 0.2 mm and the central wavelength of selective reflection is λ.
0 was 530 nm, wavelength band Δλ was 70 nm, and maximum reflectance was 98% (non-polarization measurement condition). Here, the light absorption plate 10 may be a polymer film, a substrate, or a metal plate other than methacrylic resin, which is dyed black.

Further, as the cholesteric liquid crystal polymer, there may be used one in which a cholesteric structure is fixed by forming a cholesteric structure from a lyotropic cholesteric liquid crystal using a photopolymerizable unsaturated monomer as a solvent and then photopolymerizing the cholesteric structure. Further, the light absorbing plate 10, the cholesteric liquid crystal polymer and the transparent supporting substrates 12 and 12 'may be laminated and integrated by press heating.

When the reflection type liquid crystal electro-optical device manufactured in this way is observed under the condition of normal incidence of white light, A in FIG.
In the area where the drive voltage is not applied like the area,
The incident light 21 is hardly observed as the reflected light 22 and exhibits a black display. On the other hand, in the region B to which the drive voltage is applied, the incident light 21 ′ is observed as the reflected light 22 ′ which is colored bright green.

Next, when the reflection type liquid crystal electro-optical device was mounted on a wrist watch and observed, a clear green display was obtained on a deep black background, which was brighter than that of the first embodiment. Furthermore, the green color changes subtly depending on the viewing angle, showing a so-called iridescent, noble and beautiful unique hue, which significantly improves the aesthetic or artistic added value of the digital wristwatch. Further, when the temperature was observed in the range of -20 ° C to 90 ° C, the green display hardly changed, which satisfied the actual operating environment conditions of the wristwatch.

Further, by using the nematic cholesteric phase transition type guest-host system (positive type) for the liquid crystal display element 6, it was possible to display deep black on a clear green background. When the black plate was replaced with a dark red light absorbing plate, the color tone when observed from the front changed to yellow green, and a beautiful display of yellow green was realized on a deep black background.

(Embodiment 3) In FIG. 4, the transparent substrates 2 and 2'are made of smooth glass plates, but transparent polymer films may be used. On the incident surface side of the transparent substrate 2, the antireflection film 1 is provided in order to reduce surface reflection in the visible light region.
1 was coated. The transparent electrodes 3 and 3 ′ provided on the transparent substrates 2 and 2 ′ are formed by dividing a transparent conductive film made of an ITO film by photolithography. Transparent substrate 2 '
A nematic liquid crystal material having a positive dielectric anisotropy was dissolved and mixed with 2% by weight of a black anthraquinone type dichroic dye, and then emulsified in a water-soluble polymer and dried. Then, a so-called polymer dispersed guest-host type liquid crystal display element 6 was produced by placing the transparent substrate 2 thereon to form a cell. In addition to this, as the liquid crystal display element 6 which does not use a polarizing plate, an operation mode such as a nematic cholesteric phase transition type guest-host system or a cholesteric nematic phase transition type guest-host system can be used.

The liquid crystal display element 6 thus produced is adhered to the surface of the transparent substrate 2'side by an ester type optical adhesive or a pressure sensitive adhesive made of a copolymer of butyl acrylate and 2 ethylhexyl acrylate with an acrylic monomer. A phase of a specific wavelength is converted by 180 degrees with a cholesteric liquid crystal polymer on the light absorption plate 10 through the layer 1.
The two wavelength plates 13 were sandwiched and laminated together.

The adhesive layer 7 can be used as long as it is a transparent adhesive or pressure-sensitive adhesive, and also has a function of reducing Fresnel reflection at each interface. As the light absorbing plate 10, a black plate dyed with methacrylic resin in black so as to have absorption in the visible light region was used. Cholesteric liquid crystal polymer is a polyethylene terephthalate film transparent support substrate, sandwiched by a polymer of cholesteric liquid crystal structure of a polypeptide such as polyglutamate which selectively reflects right-handed circularly polarized light of a specific wavelength, and then rapidly cooled after heating at a specific temperature. The thickness was about 0.1 mm, the selective reflection center wavelength λ0 was 530 nm, the wavelength band Δλ was 70 nm, and the maximum reflectance was 48% (non-polarization measurement condition).

The half-wave plate 13 is a stretched polymer film, which is made of polyester, polycarbonate, polystyrene or the like and has a retardation Δnd of about half of the selective reflection center wavelength λ 0 of the cholesteric liquid crystal polymers 9 and 9 '. 265 nm. Here, the maximum reflectance in the structure in which the half-wave plate 13 is sandwiched between cholesteric liquid crystal polymers was about 92% (non-polarization measurement condition).

Further, the light absorbing plate 10 may be a polymer film, a substrate or a metal plate other than methacrylic resin, which is dyed black. Further, as the cholesteric liquid crystal polymer, a lyotropic cholesteric liquid crystal having a cholesteric structure formed by using a photopolymerizable unsaturated monomer as a solvent to form a cholesteric structure and then photopolymerizing the cholesteric structure can be used. In addition, the light absorption plate 10 and the half-wave plate 1
The cholesteric liquid crystal polymer sandwiching 3 may be laminated and integrated by press heating.

When the reflection type liquid crystal electro-optical device manufactured in this manner is observed under the condition of normal incidence of white light, A in FIG.
In the area where the drive voltage is not applied like the area,
The incident light 21 is hardly observed as the reflected light 22 and exhibits a black display. On the other hand, in the region B to which the drive voltage is applied, the incident light 21 ′ is observed as the reflected light 22 ′ which is colored bright green.

Next, when the reflection type liquid crystal electro-optical device was mounted on a wrist watch and observed, a clear green display was obtained on a deep black background, which was a brighter display than in the first embodiment. Furthermore, the green color changes subtly depending on the viewing angle, showing a so-called iridescent, noble and beautiful unique hue, which significantly improves the aesthetic or artistic added value of the digital wristwatch. Further, when the temperature was observed in the range of -20 ° C to 90 ° C, the green display hardly changed, which satisfied the actual operating environment conditions of the wristwatch.

In addition, the fact that the liquid crystal display element 6 uses the reverse mode polymer dispersion type guest-host system (positive type) to display deep black on a clear green background is added.

[0034]

As described above, according to the present invention, the cholesteric liquid crystal polymer reflector having selective reflectivity in the visible light region is provided between the liquid crystal display element and the light absorbing plate having absorption in the visible light region. With such a structure, it enables cholesteric color display with clearer and more noble tones than the dye-type color filter system, realizes a lower manufacturing cost than the dichroic mirror system, and has a low molecular weight. Compared to the cholesteric liquid crystal cell system, we have realized a display with less change in display color and less shadow over a wider temperature range.

Further, since the quarter-wave plate for converting the phase of light of a specific wavelength by 90 degrees is sandwiched between the liquid crystal display element and the cholesteric liquid crystal polymer reflector, the liquid crystal display element is polarized. Reflection efficiency with a plate is 1
Compared to the case without the / 4 wave plate, it was possible to raise it significantly.

Further, since the cholesteric liquid crystal polymer reflector is made up of a cholesteric liquid crystal polymer that reflects right-handed circularly polarized light of a specific wavelength and a cholesteric liquid crystal polymer that reflects left-handed circularly polarized light, the optical axes of the two are made parallel to each other. The reflection efficiency in the case where the display element does not have a polarizing plate can be increased to about twice that in the case where the display element has one layer.

Further, the cholesteric liquid crystal polymer reflection plate converts the phase of the light of the specific wavelength by 180 degrees between the two cholesteric liquid crystal polymers which selectively reflect circularly polarized light of the same wavelength in the specific rotation direction. Since the structure has a structure in which the wave plates are sandwiched in between, the reflection efficiency in the case where the liquid crystal display element does not have a polarizing plate can be increased to about double that in the case of a single layer.

Further, since the light absorption plate has a structure in which the layers of the cholesteric liquid crystal polymer are laminated on the support, the handling in manufacturing is simplified and the overall thickness can be reduced. Further, at least one adhesive layer is provided between the liquid crystal display element and the light absorption plate, and the liquid crystal optical element, the cholesteric liquid crystal polymer reflection plate, and the light absorption plate are laminated. It was much brighter and easier to see than the structure.

As described above, the reflection type liquid crystal electro-optical device of the present invention has a distinctive color display capability which is clear and has excellent aesthetic potential, and is excellent in cost and environment resistance. It is effective as a display for other mobile devices.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration sectional view of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration cross-sectional view of an example of a conventional reflective liquid crystal electro-optical device.

FIG. 3 is an explanatory diagram showing a configuration sectional view of a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a configuration sectional view of a third embodiment of the present invention.

FIG. 5 is a diagram illustrating the principle of the present invention.

FIG. 6 is a spectrum diagram of color display characteristics of the reflective liquid crystal electro-optical device according to Example 1 of the present invention.

[Explanation of symbols]

 1 Polarizing plate 1'Polarizing plate 2 Transparent substrate 2'Transparent substrate 3 Transparent electrode 3'Transparent electrode 4 Alignment film 4'Alignment film 5 Liquid crystal layer 6 Liquid crystal display element 7 Adhesive layer 7'Adhesive layer 8 1/4 Wave plate 9 Cholesteric Liquid crystal polymer reflector 10 Light absorbing plate 11 Antireflection film 12 Transparent supporting substrate 12 'Transparent supporting substrate 13 1/2 wavelength plate 14 Spacer 15 Reflector 16 Color filter 17 Observer 21 Incident light 21' Incident light 22 Reflected light 22 ' Reflected light 23 Transmitted light 24 Reflected light

Claims (7)

[Claims] 1. A reflection characterized in that a cholesteric liquid crystal polymer reflector which exhibits selective reflectivity at a specific wavelength in the visible light region is provided between a liquid crystal display device and a light absorbing plate having absorption in the visible light region. Type liquid crystal electro-optical device. 2. A quarter-wave plate for converting the phase of light of a specific wavelength by 90 degrees between the liquid crystal display element and a cholesteric liquid crystal polymer reflective plate that exhibits selective reflection at the specific wavelength of the visible light region. The reflective liquid crystal electro-optical device according to claim 1, having a structure for sandwiching. 3. The cholesteric liquid crystal polymer reflector comprises a cholesteric liquid crystal polymer that reflects right-handed circularly polarized light having a specific wavelength and a cholesteric liquid crystal polymer that reflects left-handed circularly polarized light with their optical axes parallel to each other. The reflective liquid crystal electro-optical device according to claim 1. 4. The cholesteric liquid crystal polymer reflector plate converts the phase of light having a specific wavelength by 180 degrees between two cholesteric liquid crystal polymers that selectively reflect circularly polarized light of a specific wavelength in the same rotation direction. 2. The reflection type liquid crystal electro-optical device according to claim 1, wherein the reflection type liquid crystal electro-optical device has a structure in which the wave plates are sandwiched in between. 5. A reflective liquid crystal electro-optical device according to claim 1, wherein the light absorption plate has a structure in which a layer of cholesteric liquid crystal polymer is laminated on a support. 6. The reflective liquid crystal electro-optical device according to claim 1, wherein each of the plates constituting the reflective liquid crystal electro-optical device is integrally formed by an adhesive layer. apparatus. 7. The reflective liquid crystal electro-optical device according to claim 1, wherein the light absorbing plate is a black plate.