JPH0961814A - Reflective liquid crystal display device and production of selective reflection layer used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal display device which is substantially free from loss of light, is bright and is good in contrast by providing the device with a first substrate which is laminated with a first transparent electrode layer and a first oriented film, a second substrate which is laminated with a second transparent electrode layer and a second oriented film and has a selective reflection layer and light absorption layer and a light controllable layer between the first oriented film and the second oriented film. SOLUTION: The first substrate is formed by laminating the transparent electrodes 3 of MIM elements and the oriented film 4 on an upper substrate 1. The second substrate is formed by laminating the selective reflection layer 7, the transparent electrodes 5 and the oriented film 4 on the one surface of a lower substrate 2 and arranging the light absorption layer 10 for absorbing light on the other surface. The selective reflection layer 7 is formed by sealing spirally arranged high polymers therein and selectively reflects the light of a specific wavelength. In addition, the layers to selectively reflect the light of red, the layers to selectively reflect the light of blue and the layers to selectively reflect the light of green are arranged in correspondence to the individual elements. The light controllable layer formed by orienting and dispersing the high polymers 8 in liquid crystals are disposed between the oriented film 4 of the first substrate and the oriented film 4 of the second substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device used for a liquid crystal television, a liquid crystal projector, a liquid crystal display and the like. More specifically, the present invention relates to a reflective liquid crystal display device capable of monochrome display or color display that does not require a backlight. The present invention also relates to a method of manufacturing a selective reflection layer used in the reflective liquid crystal display device.

[0002]

2. Description of the Related Art Japanese Patent Publication 7-9511 and Japanese Patent Publication 7-360
In 68, a dimming layer in which liquid crystal is dispersed in a polymer sandwiched between two substrates and supported by a supporting medium and a dimming layer formed by an evaporation technique such as sputtering are separated by a distance of the supporting medium. A liquid crystal display device is described in which a dielectric film that maintains the above is maintained, and by limiting the thickness of the dielectric film to a function of λ / 2, bright display is possible by enhancing interference in the supporting medium. I am trying.

Digest of Symposium
Information Display 19
94 and p399, a light source (not shown in the figure), a beam splitter (not shown in the figure), a polarizing plate 32, and a twisted nematic (TN) liquid crystal element 33 as shown in FIG.
a or 33b, a λ / 4 wave plate 34, a reflective layer 35 composed of a liquid crystalline siloxane polymer having a spiral structure patterned in red, blue and green, and a reflective liquid crystal display device (projector) composed of a light absorber 36. ing. When the spiral of the polymer reflection layer having a spiral structure is left-handed, the light 37 reflected by the beam splitter is reflected by the polarizing plate 3
2. Transverse white linearly polarized light 38a passing through the TN element 33a in the off state, and left circularly polarized light L39 by passing through the λ / 4 wave plate 34, light λΔL40 in the specific wavelength range of the left circularly polarized light L39. The light 41 outside the range is reflected by the left-handed polymer reflection layer 35, passes through the polymer reflection layer, and is absorbed by the light absorption layer 36. This scattered reflected light λΔL40 is converted into laterally polarized linearly polarized light 38b by passing through the λ / 4 wavelength plate 34, and further, the TN element 33a.
The light is illuminated by 90 degrees at 90 ° C., passes through the polarizing plate 32, and is observed as observation light 44. When the TN element is turned on, the white linearly polarized light that has passed through the TN element 33b in the on state becomes the longitudinally polarized linearly polarized light 42.
The light of the right circularly polarized light R43 in the entire wavelength range passes through the left-handed polymer reflection layer 35 and is absorbed by the light absorption layer 36. Therefore, the display is black.

In Japanese Patent Laid-Open No. 2-149881, SiO2 and TiO2 are formed on a counter substrate combined with a TFT element substrate.
There is described a liquid crystal display device in which a multilayer interference film in which and are thinned by sputtering are alternately stacked is provided, and the interference light is changed by controlling light passing through the liquid crystal layer to perform display.

[0005]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 7-9511,
In the technique disclosed in Japanese Patent Publication No. 7-36068, a supporting medium for keeping a certain distance is required, so that a so-called double image is generated in the displayed information. Further, in a liquid crystal display device using a multilayer interference film formed by a vapor deposition method, it is necessary to stack many layers of inorganic oxides using a vacuum device, resulting in high cost. There was a problem that the manufacturing process was complicated because it had to be controlled.

Digest of Symposium
Information Display 19
According to the technique disclosed in P.94, p.399, in a liquid crystal display device in which a polymer reflection layer having a spiral structure is combined with a λ / 4 wavelength plate, a polarizing plate, etc., one polarizing plate is indispensable. 50% is absorbed by the polarizing plate and the display becomes dark. If the polarization axes of the wave plate, polarizing plate and TN element are not strictly adjusted, the light utilization efficiency will be lost and the display will become dark and the contrast will decrease. Since the wavelength range of the light reflected by the polymer reflective layer having a value changes depending on the incident angle of the light, the display becomes dark except in a specific direction (usually perpendicular to the polymer reflective layer) from the relationship with the polarization axis. However, there is a problem that the display quality is deteriorated due to the decrease in contrast.

According to the technique disclosed in Japanese Unexamined Patent Publication No. 2-149881, in a liquid crystal display device using a multilayer interference film formed by a sputtering method, many layers of indefinite oxides must be laminated by using a vacuum device. Therefore, there are problems that the cost becomes high and that the manufacturing process is complicated because the film thickness of each film must be strictly controlled.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and has an object to obtain a liquid crystal display device having a wide viewing angle and a small change in a coloring state due to a temperature change. Have.

A first substrate on which a first transparent electrode layer and a first alignment film are sequentially laminated on one surface, and a second transparent electrode layer and a second alignment film on one surface A second substrate having a selective reflection layer having a function of selectively reflecting light of a specific wavelength and a light absorption layer having a function of absorbing light, in which spirally arranged polymers are encapsulated. A light control layer disposed between the first alignment film and the second alignment film and having a function of scattering or transmitting light depending on the presence or absence of an electric field. If there is a light control layer that scatters light,
Since it is equivalent to that light is incident on the polymer reflective layer having a spiral structure from all directions, light having a wavelength selectively reflected by the polymer reflective layer is reflected in all directions, Since the averaged reflection intensity and the light having the wavelength are observed, there is no problem that the display quality is deteriorated in a direction other than a specific direction, and good display quality is realized in any direction.

A first substrate having a transparent electrode layer and a first alignment film sequentially stacked on one surface, and a reflective electrode layer and a second alignment film sequentially stacked on one surface to form a spiral. Arranged between the first alignment film and the second alignment film, and a second substrate having a selective reflection layer having a function of selectively reflecting light of a specific wavelength, in which macromolecules arranged in a matrix are encapsulated. And a light control layer having a function of scattering or transmitting light depending on the presence or absence of an electric field. If there is a light control layer that scatters light,
Since it is equivalent to that light is incident on the polymer reflective layer having a spiral structure from all directions, light having a wavelength selectively reflected by the polymer reflective layer is reflected in all directions, Since the averaged reflection intensity and the light having the wavelength are observed, there is no problem that the display quality is deteriorated in a direction other than a specific direction, and good display quality is realized in any direction.

In the liquid crystal display device, the reflective layer has a function of selectively reflecting visible light and absorbing light having a complementary color relationship with the visible light. (Description of action) In addition, red, green and blue, or
Color display is also possible by assigning to each pixel a portion that selectively reflects light of each wavelength of cyan, magenta, and yellow.

The method of manufacturing the selective reflection layer used in the reflection type liquid crystal display device of the present invention has the following features.

Forming an alignment film on one surface of the transparent substrate; forming a monomer layer on the alignment film; and irradiating the monomer with light to polymerize the monomers to arrange them in a spiral shape. And a step of forming a polymer layer,
including.

Further, a step of forming an alignment film on one surface of the transparent substrate, a step of forming a first monomer layer on the alignment film, and a light transmitting portion and a light shielding portion on the first monomer layer. And irradiating light from above the photomask while maintaining the first monomer layer at the first temperature to remove the monomer at a position overlapping with the light transmitting portion of the first photomask. Polymerizing to form a first polymer layer arranged in a spiral shape, and the first polymer layer left unpolymerized at a position overlapping the light-shielding portion of the first photomask.
The step of washing the monomer layer, the step of forming a second monomer layer on the alignment film, and the step of arranging a second photomask having a light transmitting portion and a light shielding portion on the second monomer layer. While maintaining the second monomer layer at the second temperature, light is radiated from above the second photomask to polymerize the monomer at a position overlapping with the light transmitting portion on the second photomask to form a spiral shape. The method includes a step of forming an arrayed second polymer layer, and a step of cleaning the second monomer layer remaining unpolymerized at a position overlapping with the light shielding portion of the second photomask.

Further, a step of forming a third monomer layer on the alignment film, and a third photomask having a light transmitting portion and a light shielding portion are arranged on the third monomer layer and the third photomask is arranged. While maintaining the monomer layer at the third temperature, light is radiated from above the third photomask to polymerize the monomer at a position overlapping with the light transmitting portion on the third photomask, and the third layer is arranged in a spiral shape. The step of forming a polymer layer of
Further has.

A fifth alignment film formed on one surface of the first transparent film made of a polymeric material and a sixth alignment film formed on one surface of the second transparent film made of a polymeric material. The first alignment film and the second alignment film are disposed so as to face each other, a monomer is enclosed between the fifth alignment film and the sixth alignment film, and the first transparent film is provided in the monomer at a constant temperature. Ultraviolet rays are radiated through the film or the second transparent film to polymerize the monomers to form a polymer layer arranged in a spiral shape, and the first transparent film having the fifth alignment film and the first transparent film. The second transparent film having the alignment film 6 is peeled off.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 is a sectional view of a liquid crystal display device according to the present invention.

In the figure, 1 is an upper substrate, 2 is a lower substrate, 3 is an active element including a transparent electrode, 4 is an alignment film, 5 is a transparent electrode, 6 is an insulating film, 7 is a selective reflection layer, and 8 is a polymer. , 9 is a liquid crystal, and 10 is a light absorbing layer. In FIG. 1, the transparent substrate 3 of the MIM element and the alignment film 4 were laminated on the upper substrate 1 to form a first substrate. Further, the selective reflection layer 7, the transparent electrode 5 and the alignment film 4 are laminated on one surface of the lower substrate 2 and the light absorption layer 10 having a function of absorbing light is arranged on the other surface of the lower substrate 2 to form the second substrate. Was formed. The selective reflection layer 7 has a function of selectively reflecting light of a specific wavelength, in which a polymer arranged in a spiral shape (also referred to as a cholesteric structure or a chiral structure) is encapsulated. In addition, a layer that selectively reflects red light, a layer that selectively reflects blue light, and a layer that selectively reflects green light are arranged corresponding to each element. Then, a liquid crystal cell was formed by providing a light control layer in which a polymer is aligned and dispersed in the liquid crystal between the alignment film of the first substrate and the alignment film of the second substrate. The light control layer here has a function of scattering light when an electric field is applied between the transparent electrode 3 and the transparent electrode 5 in the active element, and transmitting light when the electric field is not applied.

When an electric field is applied, the light incident from the upper substrate 1 is scattered by the light control layer. The light scattered in the lower substrate direction is reflected only by the selective reflection layer 7 and has a specific wavelength, and is scattered again in the light control layer. In this way, each pixel is colored.
The light incident from the upper substrate when no electric field is applied between the electrodes passes through the light control layer and is absorbed by the light absorption layer, or is reflected in a specific direction by the selective reflection layer, so the reflected light does not reach the user. , The display becomes black.

FIG. 2 shows a method of forming the selective reflection layer provided on the lower substrate.

In the figure, 11 is a chiral agent S-1011 (M
Product name of erck) Acrylic monomer containing 0.7%

[0022]

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Reference numeral 12 is a photomask, 13 is a light transmitting portion of the photomask, 14 is curing light for curing the acrylic monomer, 15 is a portion for selectively reflecting the cured red visible light, and 16 is newly formed. Uncured acrylic monomer, 17 is a portion that selectively reflects cured green visible light, 1
Reference numeral 8 is a portion for selectively reflecting the hardened blue visible light. First, as shown in FIG. 2A, an alignment film 4 (made by Nippon Synthetic Rubber Co., Ltd.) is formed on the lower substrate 2 by an ordinary spin coating method.
-8409) was applied and baked. An acrylic monomer layer 11 represented by the chemical formula 1 was formed on the alignment film 4 by a spin coating method to a film thickness of about 30 μm. Next, while keeping the substrate having the alignment film 4 and the acrylic monomer layer 11 thus obtained at 32 ° C., the light 14 having a wavelength at which the acrylic monomer is cured and polymerized through the light transmitting portion 13 of the photomask 12. Was partially irradiated. Then, the portion not irradiated with the curing light was washed off with a solvent to obtain an acrylic polymer 15 (FIG. 2 (d)). The pitch length of the acrylic polymer depends on the reaction temperature during photocuring. In this case, an acrylic polymer 15 which selectively reflects visible light in the red wavelength region having a pitch length corresponding to a reaction temperature of 32 ° C. was obtained (FIG. 2 (c)). Next, the acrylic monomer 16 is again spin-coated to about 30 μm.
The coating was applied to a film thickness of m, and the curing light for curing the acrylic monomer was irradiated while maintaining the temperature at 45 ° C (Fig. 2 (e)). Then, the portion not irradiated with the curing light was washed away with a solvent to obtain an acrylic polymer 19. The acrylic polymer 19 (FIG. 2 (f)) selectively reflects visible light in the green wavelength range having a pitch length corresponding to a reaction temperature of 45 ° C. Next, in the same manner, the acrylic monomer was spin-coated again to about 3 times.
Applying to a film thickness of 0 μm, irradiating with curing light that cures the acrylic monomer while maintaining the temperature at 65 ° C, and washing away the part not exposed to curing light with a solvent, pitch length corresponding to the reaction temperature of 65 ° C. An acrylic polymer 18 that selectively reflects visible light in the blue wavelength range is obtained. On the substrate having a selective reflection layer made of an acrylic polymer that selectively reflects the light corresponding to each of the red, blue and green wavelength regions thus obtained, polyimide is spin-coated to a thickness of 2 μm as an insulating film. Then, a film was formed and baked, and a stripe electrode made of ITO was formed on this polyimide by a usual method. Thus, the second substrate having the selective reflection layer and the transparent electrode layer was obtained. The upper substrate is MI
An M element group and an alignment film were formed to obtain a first substrate.

The first substrate and the second substrate thus obtained were pasted together with a sealing agent through a 6 μm plastic spacer to form an empty cell with a gap of about 6 μm. In the gap of this empty cell, M361, SI51
3, 5% by weight of a mixed dye prepared by mixing M34 (all manufactured by Mitsui Toatsu Dyes Co., Ltd.) at a mixing ratio of 14: 16: 4 (weight ratio), and a chiral substance CB-15 (manufactured by Merck).
Liquid crystal TL-202 (manufactured by Merck)
After dissolving against

[0025]

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[0026]

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The ultraviolet curable monomer represented by
They were mixed in a (weight ratio), and further mixed in a ratio of (liquid crystal + dichroic dye): mixed monomer = 93: 7 (weight ratio), and sealed in a panel under vacuum. Further, in order to make the monomer into a polymer, the intensity of UV light at a wavelength of 350 nm is 4.5 mW.
Irradiation with UV light of / cm @ 2 for 25 minutes at 50.degree. After curing, the polymer had countless particles having a length of about 5 μm and a diameter of about 0.8 μm. In this way, a light control layer containing a liquid crystal and a particulate polymer was prepared.

The liquid crystal display device thus obtained is
When no electric field is applied to the device, visible light of a specific wavelength is selectively reflected by the selective reflection layer having a spiral structure, and the other light is absorbed by the light absorption layer, and thus appears to be colored. When an electric field is applied, incident light is scattered by the light control layer, so that it appears cloudy.

In addition to pure Ta as the metal and insulator for forming the MIM element, various metals and oxides may be mixed.

An underlayer may be formed between the substrate and the device to improve the adhesion.

As the non-linear element, besides the MIM element, a lateral type MIM element, a back-to-back type MIM element,
MSI element, diode ring element, varistor element, a
-SiTFT element, polycrystalline SiTFT element, CdSeT
An FT element or the like can be used. In this embodiment, an example of the active element, especially the MIM element is shown.
It goes without saying that this example can be applied to a passive drive liquid crystal display device in which transparent electrodes are arranged in a matrix.

To form these elements, a film of a necessary metal or the like may be formed by low pressure CVD, plasma CVD, sputtering, ion plating, vapor deposition, plating, coating, anodic oxidation, thermal oxidation, or the like. . afterwards,
A resist or the like is patterned using a mirror projection, stepper, proximity, etc., and a pattern is formed by wet or dry etching. The pattern may be directly produced by a laser or the like.

In the liquid crystal, a chiral component, a dichroic dye,
You may contain a polymerization initiator etc. As the liquid crystal, those used for ordinary liquid crystal display elements can be preferably used, but in order to improve the scattering degree, the birefringence anisotropy of the liquid crystal, Δn, is preferably 0.15 or more. Conversely, when n is 0.
If it is 4 or more, it is difficult to obtain liquid crystal. Moreover, in order to drive with an active element, the specific resistance of the liquid crystal is 1 × 10.
9 Ω · cm, 1 × 10 10 Ω · cm or more, more preferably 2
× 10 12 Ω · cm or more is desirable for keeping the retention rate high and improving the display quality. As the material used for the substrate, soda glass, quartz glass, alkali-free glass, Si single crystal, sapphire substrate, thermosetting polymer, thermoplastic polymer and the like are preferably used. The polymer material is not particularly limited as long as it does not adversely affect the liquid crystal polymer composite sandwiched between the substrates.
In addition to T, polyether sulfone, epoxy curing resin,
Ordinary thermoplastic or thermosetting resins such as phenoxy cured resin and polyallyl ether are preferably used. Further, when it is required to reduce the transmittance of gas, water, etc., scratch resistance, flexibility, etc., a plurality of resins may be used in combination instead of alone. In addition, various inorganic films may be formed alone or in a laminated form, if necessary.
Either a counter electrode or a device electrode may be formed on the substrate made of these polymer materials. Further, both of the two substrates sandwiching the light control layer may be composed of a polymer substrate.

In the present invention, a transparent electrode is connected to the active element, but a reflective electrode may be used. The reflective member used as the reflective electrode is made of Al, Cr, Mg, Ag, A
A simple metal such as u or Pt, or a mixture thereof is preferable, and Ag, Al, Cr, and an Al-Mg mixture are more preferable, and an Al-Mg mixture is particularly preferable in terms of stability and reflectance. The amount of Mg added is preferably 0.1 to 10% by weight, and particularly preferably 0.5 to 5% by weight in terms of stability, reflectance, operability and the like. Further, when the reflective electrode is used, the light absorption layer is unnecessary.

As the chiral component, ordinary TN, ST
CB-15, C-15, S used for N and FTN
811, S1082 (all manufactured by Merck), CM-1
9, CM, CM-20, CM-21, CM-22 (all manufactured by Chisso Co., Ltd.) are preferably used in an amount of 0.01 to 10% by weight when added to the light control layer.
And preferably 0.1 to 5% by weight. 0.01
If it is less than 10% by weight, the effect is small, and if it is more than 10% by weight, the driving voltage becomes high, and the dimming layer cannot be driven by an ordinary element. As the dichroic dye, azo type, anthraquinone type, naphthoquinone type, perylene type, quinophthalone type, azomethine type and the like which are commonly used for GH are preferably used. Among them, from the viewpoint of light resistance, the anthraquinone type alone or a mixture with other dyes as necessary is particularly preferable. These dichroic dyes are appropriately mixed and used depending on the required color.

The polymer used in the light control layer is preferably an ultraviolet curable monomer because of the ease of manufacturing a liquid crystal device. A monofunctional acrylate, a bifunctional acrylate, a polyfunctional acrylate, or the like is preferably used as the UV-curable monomer. In order to improve the degree of scattering, it is desirable that these monomers contain at least one benzene ring in their molecular structure. These monomers may contain a chiral component. These monomers may be used alone or after mixing with other monomers or oligomers,
It may be irradiated with ultraviolet rays to be polymerized.

In the present embodiment, the case where the twist angle is 180 degrees is shown, but other twist angles may be used.
In addition, the above liquid crystal display device and a normal TN mode, TN
A combination of mode and retarder, or STN mode and STN with a twist angle of 180-270 degrees
A mode in which a retardation plate is combined, a GH mode, or a combination in which a GH mode and a retardation plate are combined may be used.

In the present embodiment, the light absorption layer is provided on the opposite side of the selective reflection layer with the substrate interposed, but the light absorption layer may be formed between the transparent electrode layer and the alignment film.

In the present embodiment, the arrangement of each color of the polymer reflection layer having a spiral structure is a mosaic pattern, but it may be a stripe pattern or a triangle pattern. The photocurable resin is
A photosensitive resin such as an epoxy resin, an acrylate resin, or a polybutadiene resin may be used. The selective reflection layer arranged in a spiral may have irregularities on its surface in order to remove unnecessary specular reflection and the like.

(Second embodiment) As shown in FIG. 8, two 100 μm-thick polyester films 19 (manufactured by DuPont, trade name Mylar) are spun with an orientation film 20 (AL-3409 manufactured by Japan Synthetic Rubber). A coat was applied and baked to form a film. Next, the alignment film was aligned in a certain direction by a normal rubbing method, and the two films were laminated with a gap agent of 10 μm so that the alignment directions of the two films were orthogonal to each other. Next, between these two films,

[0041]

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[0042]

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[0043]

[Chemical 6]

A mixture of acrylic monomers represented by (2: 1: 1) was encapsulated while heating at 80 ° C. Further, after leaving at 85 ° C for 2 hours to stabilize the alignment, 85 ° C
Then, the monomer was cured by irradiating with ultraviolet rays having an intensity of 50 mJ at 355 nm for 5 minutes to cure the monomer to form a polymer layer 21 arranged in a spiral shape.

FIG. 9 shows an example of the reflective liquid crystal display device in this example.

In the figure, 22 is an upper substrate, 23 is a lower substrate, 2
4 is an active element, 25 is an alignment film, 26 is an electrode, 27
Is a selective reflection layer, 28 is an adhesive material, 29 is a polymer, 30 is a liquid crystal, and 31 is a light absorbing layer. As shown in FIG. 9, after peeling off the two polyester films 19 and isolating the polymer layer 21 having a helical structure, the polymer layer 21 was attached to a liquid crystal display device prepared in the same manner as in Example 1 via an adhesive 28,
Further, a light absorption layer 31 was attached).

When this is combined with a liquid crystal display device, when the electric field is not applied to the element, the light of a specific wavelength is reflected by the selective reflection layer having a spiral structure, and the other light is absorbed by the light absorption layer. Therefore, it is displayed in black. When an electric field is applied, incident light is scattered by the light control layer, so that it appears cloudy.

In the present embodiment, one type of selective reflection layer having a spiral structure is used, but the three primary colors of RGB or each color such as yellow, cyan and magenta can be displayed.
A polymer reflection layer similar to that of the first embodiment may be prepared and used.

In this embodiment, the polymer reflection layer is peeled from the film and used alone, but it may be used with the film attached.

[0050]

As described above, the reflective liquid crystal display device of the present invention comprises a first substrate on which a first transparent electrode layer and a first alignment film are sequentially laminated on one surface, A selective reflection layer having a second transparent electrode layer and a second alignment film, which are sequentially laminated on one surface, and in which a polymer arranged in a spiral shape is encapsulated and which has a function of selectively reflecting light of a specific wavelength. A second substrate having a light absorption layer having a function of absorbing light, and a function of scattering or transmitting light depending on the presence or absence of an electric field, which is disposed between the first alignment film and the second alignment film. And a light control layer. Therefore, unlike a conventional pigment filter that utilizes light absorption, it utilizes light interference, so that a liquid crystal display device with little light loss and bright contrast can be obtained.

Further, since there is no absorption of light and decomposition of pigment, a liquid crystal display device having excellent light resistance and reliability can be obtained.
Further, due to the interference of light, the wavelength of the light selectively reflected can be easily changed by changing the pitch of the helical structure and the polymerization temperature, and the production is easy.

A first substrate having a transparent electrode layer and a first alignment film sequentially stacked on one surface, and a reflective electrode layer and a second alignment film sequentially stacked on one surface. A second substrate having a selective reflection layer in which spirally arranged polymers are encapsulated and which has a function of selectively reflecting light of a specific wavelength;
A light control layer disposed between the first alignment film and the second alignment film and having a function of scattering or transmitting light depending on the presence or absence of an electric field. Therefore, unlike conventional pigment filters that utilize the absorption of light,
Since the interference of light is used, there is almost no loss of light and a liquid crystal display device having a bright and good contrast can be obtained. Also, since there is no light absorption or pigment decomposition,
A liquid crystal display device having excellent light resistance and reliability can be obtained. Further, due to the interference of light, the wavelength of the light selectively reflected can be easily changed by changing the pitch of the helical structure and the polymerization temperature, and the production is easy.

The method of manufacturing the selective reflection layer of the present invention is
A step of forming an alignment film on one surface of a transparent substrate, a step of forming a monomer layer on the alignment film, and a polymer layer in which the monomer is polymerized by irradiating the monomer with light to form a helical arrangement. And the process of making. Therefore, it is possible to easily change the wavelength of the light selectively reflected by the interference of light by changing the type of the alignment film, the pitch of the orientation spiral structure of the alignment treatment performed on the alignment film, and the polymerization temperature. Easy to manufacture.

Further, a step of forming an alignment film on one surface of the transparent substrate, a step of forming a first monomer layer on the alignment film, and a light transmitting portion and a light shielding portion on the first monomer layer. And irradiating light from above the photomask while maintaining the first monomer layer at the first temperature to remove the monomer at a position overlapping with the light transmitting portion of the first photomask. Polymerizing to form a first polymer layer arranged in a spiral shape, and the first polymer layer left unpolymerized at a position overlapping the light-shielding portion of the first photomask.
The step of washing the monomer layer, the step of forming a second monomer layer on the alignment film, and the step of arranging a second photomask having a light transmitting portion and a light shielding portion on the second monomer layer. While maintaining the second monomer layer at the second temperature, light is radiated from above the second photomask to polymerize the monomer at a position overlapping with the light transmitting portion on the second photomask to form a spiral shape. The method includes a step of forming an arrayed second polymer layer, and a step of cleaning the second monomer layer remaining unpolymerized at a position overlapping with the light shielding portion of the second photomask. Therefore, it is possible to produce a polymer reflection layer suitable for a corresponding element substrate. Also,
The wavelength of the light that is selectively reflected by the interference of light can be easily changed by changing the type of the alignment film, the pitch of the orientation spiral structure of the alignment treatment applied to the alignment film, and the polymerization temperature. It's easy.

According to the present invention, it is possible to provide a liquid crystal display which does not require a backlight and has a good contrast. In addition, the manufacturing method does not require a special laser light source, etc., and the characteristics of the polymer layer having the obtained chiral structure are determined by the inherent properties of the polymer material used, so the film thickness and surface smoothness are excessive. Since it is not required to be uniform, the mass production is easy.

[Brief description of drawings]

FIG. 1 is a diagram showing a cross section of a reflective liquid crystal display device according to the present invention.

FIG. 2 is a schematic view of a method for producing a selective reflection layer containing a polymer arranged in a spiral shape, which is used in Embodiment 1 of the present invention.

FIG. 3 is a diagram showing a transmittance curve of a selective reflection layer that selectively reflects light in a red wavelength range used in the present invention.

FIG. 4 is a diagram showing a transmittance curve of a selective reflection layer which selectively reflects light in a green wavelength range used in the present invention.

FIG. 5 is a diagram showing a transmittance curve of a selective reflection layer that selectively reflects light in a blue wavelength range used in the present invention.

FIG. 6 is a diagram showing the relationship between the applied voltage and the reflectance of the reflective liquid crystal display device manufactured according to the present invention.

FIG. 7 is a diagram showing an outline of the external appearance of a reflective liquid crystal display device created by the present invention.

FIG. 8 is a schematic diagram of a method of forming a selective reflection layer according to the second embodiment of the present invention. Fig.

FIG. 9 is a diagram showing a cross section of a liquid crystal display device in which a polymer having a chiral structure and a light absorption layer are attached to a substrate of a reflective liquid crystal display device according to the present invention.

FIG. 10: Polarizing plate, TN liquid crystal device, λ according to the conventional invention
The figure which shows the operation principle of the liquid crystal display device which consists of a / 4 wavelength plate, a polymeric reflection layer, and a light absorber.

[Explanation of symbols]

1 Upper Substrate 2 Lower Substrate 3 Active Element Having Transparent Electrode 4 Alignment Film 5 Transparent Electrode 6 Insulating Layer 7 Selective Reflecting Layer 8 Polymer 9 Liquid Crystal 10 Light Absorbing Layer 11 Monomer Layer 12 Photomask 13 Light Transmitting Portion of Photomask 14 Curing light 15 Polymer layer that selectively reflects light of red wavelength 16 Monomer layer 17 Polymer layer that selectively reflects light of green wavelength 18 Polymer layer that selectively reflects light of blue wavelength 19 Polymer film 20 Alignment film 21 Polymer Layer 22 Polymer film 23 Lower substrate 24 Active element 25 Alignment film 26 Electrode 27 Selective reflection layer 28 Adhesive 29 Polymer 30 Liquid crystal 31 Light absorption layer 32 Polarizing plate 33a Off-state twisted nematic (TN)
Liquid crystal element 33b Twisted nematic (TN) liquid crystal element in the on state 34 λ / 4 wave plate 35 Reflective layer made of liquid crystalline acrylic polymer having a spiral structure patterned in red, blue and green 36 Light absorber 37 Reflected by a beam splitter Light 38a Horizontally polarized white linearly polarized light 39 Left circularly polarized light 40 Light in a specific wavelength range 41 Light other than a specific wavelength range 42 Vertically polarized linearly polarized light 43 Right circularly polarized light 44 Observed light

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location // C08F 20/18 MLY C08F 20/18 MLY (72) Inventor Hidehito Iisaka 3 Yamato, Suwa City, Nagano Prefecture 3-5, Seiko Epson Corporation

Claims (10)

[Claims] 1. A first substrate on which a first transparent electrode layer and a first alignment film are sequentially laminated on one surface, and a second transparent electrode layer and a second alignment film on one surface. A second layer having a selective reflection layer having a function of selectively reflecting light of a specific wavelength and a light absorption layer having a function of absorbing light, in which spirally arranged polymers are encapsulated. A reflective liquid crystal display device comprising: a substrate; and a dimming layer disposed between the first alignment film and the second alignment film and having a function of scattering or transmitting light depending on the presence or absence of an electric field. 2. A first substrate having a transparent electrode layer and a first alignment film sequentially laminated on one surface, and a reflective electrode layer and a second alignment film sequentially laminated on one surface. A second substrate having a selective reflection layer in which spirally arranged polymers are encapsulated and having a function of selectively reflecting light of a specific wavelength; and between the first alignment film and the second alignment film. And a dimming layer having a function of scattering or transmitting light depending on the presence or absence of an electric field, and a reflective liquid crystal display device. 3. The reflective liquid crystal display device according to claim 1, wherein the dimming layer has a polymer dispersed in the liquid crystal or a liquid crystal dispersed in the polymer. 4. The reflective liquid crystal display device according to claim 1, wherein the dimming layer transmits light in a state where no electric field is applied and emits light when an electric field is applied. A reflective liquid crystal display device having a scattering function. 5. The reflective liquid crystal display device according to claim 1, wherein the reflective layer has a function of selectively reflecting visible light and absorbing light having a complementary color relationship with the visible light. Reflective liquid crystal display device. 6. The reflective liquid crystal display device according to claim 1, wherein the selective reflection layer is 600
A reflective liquid crystal display device having a function of selectively reflecting light having a wavelength of nm or less and absorbing light having a complementary color relationship with the light of 600 nm or more. 7. A step of forming an alignment film on one surface of a transparent substrate, a step of forming a monomer layer on the alignment film, and a step of forming a spiral by polymerizing the monomer by irradiating the monomer with light. And a step of forming a polymer layer arranged in the above. 8. A step of forming an alignment film on one surface of a transparent substrate, a step of forming a first monomer layer on the alignment film, and a light transmitting portion and a light shielding portion on the first monomer layer. And irradiating light from above the photomask while maintaining the first monomer layer at the first temperature to remove the monomer at a position overlapping with the light transmitting portion of the first photomask. First polymerized and arranged in a spiral
Forming a polymer layer, cleaning the first monomer layer remaining unpolymerized at a position overlapping with the light-shielding portion of the first photomask, and forming a second monomer layer on the alignment film. A step of arranging a second photomask having a light transmitting portion and a light shielding portion on the second monomer layer, and maintaining the second monomer layer at a second temperature from above the second photomask. A step of irradiating light to polymerize a monomer at a position overlapping with a light transmitting portion on the second photomask to form a second polymer layer arranged in a spiral shape; and a light shielding portion of the second photomask And a step of washing a second monomer layer which is not polymerized and remains at an overlapping position, the method for producing a selective reflection layer. 9. The method of manufacturing a selective reflection film according to claim 8, further comprising a step of forming a third monomer layer on the alignment film, and a light transmitting portion and a light shielding portion on the third monomer layer. A third photomask is arranged, and light is irradiated from above the third photomask while maintaining the third monomer layer at the third temperature, and the third photomask is located at a position overlapping the light transmitting portion on the third photomask. And a step of polymerizing a monomer to form a spirally arranged third polymer layer, the method for producing a selective reflection layer. 10. A fifth alignment film formed on one surface of a first transparent film made of a polymeric material, and a sixth alignment film formed on one surface of a second transparent film made of a polymeric material.
Of the first transparent film and the fifth transparent film of the sixth transparent film, and a monomer is enclosed between the fifth and sixth transparent films of the first transparent film under constant temperature. Ultraviolet rays are radiated through the film or the second transparent film to polymerize the monomers to form a polymer layer arranged in a spiral, and the first transparent film having the fifth alignment film and the first transparent film. 7. A method for producing a selective reflection film, which comprises peeling off the second transparent film having the alignment film of No. 6.