JPH11109328A - Liquid crystal device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To embody a liquid crystal device capable of suppressing the degradation in visibility by imprinting of a background and illumination and the surface reflection of a front surface side substrate. SOLUTION: The front surface layer 12 consisting of nearly transparent oxide is formed on the front surface of the transparent substrate 10 on a front surface side (viewer's side). The front surface layer 12 is a porous thin film formed by a method generally called as a sol-gel method. The front surface layer 12 is formed by applying a sol-like coating liquid obtd. by hydrolysis of metal alkoxide on the substrate and curing the coating by drying, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal device and a method for manufacturing the same.

[0002]

2. Description of the Related Art Heretofore, a reflection type liquid crystal in which a liquid crystal layer is sealed between a front side substrate having translucency and a back side substrate and a reflection layer is provided on an inner surface or an outer surface of the back side substrate. The device is used. The reflection type liquid crystal device is configured so that display and the like can be read by reflecting light incident from the front side substrate by the reflection layer, and a backlight or the like is not required. It is often used as an accessory display of equipment.

As a new type of the reflection type liquid crystal device, a liquid crystal device having a composite liquid crystal layer in which liquid crystal and a polymer are dispersed and mixed has been proposed. This type of liquid crystal device has a cell structure in which a composite liquid crystal layer is sandwiched between two glass substrates provided with electrodes, and the light refractive index of the liquid crystal and polymer particles with respect to light incident on the cell structure. The difference is changed depending on the level of the applied voltage, and light is scattered or transmitted to perform display.

As an example of the above liquid crystal device, a schematic cell structure of a polymer dispersion type liquid crystal device will be described. This cell structure has a structure in which a composite liquid crystal layer is sandwiched between two glass substrates. A transparent electrode made of ITO (indium tin oxide) or the like is formed on the inner surface of one glass substrate, and Al is formed on the inner surface of the other glass substrate.
A reflective electrode serving also as a reflective layer made of, for example, Cr or Cr is formed. An alignment film made of a transparent resin is formed on these transparent electrodes and reflective electrodes, and rubbing is performed in a predetermined direction.

The gap between the glass substrates is usually about a few μm. A predetermined liquid crystal having anisotropy of refractive index and dielectric anisotropy and a polymer precursor (monomer) having photopolymerizability are provided in the gap. , Prepolymer, etc.) are injected. When the cell structure of the liquid crystal thus formed is irradiated with ultraviolet rays, the polymer precursor in the solution undergoes photopolymerization and precipitates in a state where the polymer particles are dispersed in the liquid crystal.
Thus, a polymer-dispersed composite liquid crystal layer is formed.

The liquid crystal molecules and polymer particles in the composite liquid crystal layer are
When no electric field is applied, the alignment films are oriented in substantially the same direction along the direction of the rubbing treatment performed on the alignment film. At this time, when a voltage exceeding a predetermined threshold is applied between the transparent electrode and the reflective electrode, the liquid crystal molecules having dielectric anisotropy are oriented in the direction of the electric field and change their posture. As a result, the refractive index of the liquid crystal molecules having the refractive index anisotropy seen from the outside changes, so that the liquid crystal molecules and the liquid crystal molecules are aligned in the same direction as the polymer particles without an electric field applied. The difference in the refractive index from the polymer particles also changes.

In the above composite liquid crystal layer, for example, if the difference in the refractive index between the liquid crystal molecules and the polymer particles is substantially zero in the state where no electric field is applied, the composite liquid crystal layer becomes almost transparent, so that the composite liquid crystal layer enters the cell. The light thus transmitted passes through the composite liquid crystal layer, is reflected by the reflection electrode, and is emitted again as it is. Conversely, when an electric field is applied, the refractive index of the liquid crystal molecules changes, causing a difference between the refractive index of the polymer particles and the composite liquid crystal layer. Is scattered. Of course, it is also possible to make the composite liquid crystal layer in a scattering state when no electric field is applied, and to make the composite liquid crystal layer in a transmission state when an electric field is applied.

In this type of liquid crystal device, since the optical state of the composite liquid crystal layer is controlled by utilizing the transmission and scattering of light, it can be configured without using a polarizing plate, and is configured as the above-mentioned reflection type liquid crystal device. In this case, since the incident light can be efficiently used for display, there is an advantage that the brightness of the display can be ensured.

[0009]

In the above-mentioned conventional polymer-dispersed liquid crystal device, when it is constructed as a reflection type liquid crystal device, the brightness of display can be improved. There is a problem in that the background and illumination are reflected depending on the layer, and the visibility is rather impaired.

[0010] Further, in the case of a reflection type liquid crystal device, the display is difficult to see due to the surface reflection of the front side substrate because it is configured to be visually recognized using only external light incident on the front side substrate. is there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to suppress a decrease in visibility due to reflection of a background or illumination and reflection of a surface of a front substrate in a reflection type liquid crystal device. It is an object of the present invention to realize a liquid crystal device.

[0012]

In order to solve the above-mentioned problems, the present invention provides a liquid crystal device having a liquid crystal layer between a pair of substrates, and a reflective layer on one of the pair of substrates. Wherein a porous film is provided on the surface of the other substrate opposite to the surface on the liquid crystal layer side of the other substrate.

According to this means, by forming the porous film on the surface of the front-side substrate, the reflection of the background and illumination by the reflective layer can be reduced by the optical action of the pores of the porous film. In addition to that, since the surface reflection of the substrate can be reduced, the visibility of the liquid crystal device can be improved.

Here, the porous film is made of porous SiO _2.
Is preferably a main component.

According to this means, by forming a porous film containing SiO ₂ as a main component, good adhesion and low refractive index can be obtained when glass is used as the front substrate. By controlling the thickness of the porous film, the surface reflectance of the front substrate can be further reduced.

In these cases, the porous membrane comprises:
It is preferably formed by applying and curing a sol-like coating solution obtained by hydrolyzing a metal alkoxide.

According to this means, a porous film made of a metal oxide can be easily formed at a low temperature, and the size and density of the internal pores can be controlled by the forming conditions. A porous film suitable for improving the visibility of the device can be easily formed.

In this case, it is preferable that the porous film has a thickness and a refractive index that reduce surface reflection of the front substrate.

According to this means, the apparent refractive index can be changed by controlling the porosity of the porous film, so that the refractive index of the porous film is optimized with respect to the refractive index of the front substrate. By controlling the thickness and controlling the thickness, the film can be used as an antireflection film that effectively reduces the surface reflection of the front substrate.

The liquid crystal layer is preferably a composite liquid crystal layer in which a liquid crystal and a polymer are dispersed and mixed.

According to this means, the composite liquid crystal layer can change the light transmittance by changing the difference in the refractive index between the liquid crystal and the polymer, so that an unnecessary bright display such as a polarizing plate is possible. On the other hand, the reflection of the background and the illumination in the light transmission state becomes intense. Therefore, the reflection can be particularly effectively reduced by forming the porous film on the surface of the front substrate.

Next, in a method for manufacturing a liquid crystal device having a liquid crystal layer between a pair of substrates and a reflective layer on one substrate,
After applying a sol-like coating solution obtained by hydrolyzing a metal alkoxide on the surface of the one substrate, forming a light-transmitting porous film by performing a curing treatment. This is a method for manufacturing a liquid crystal device.

According to this means, the porous film can be easily formed on the surface of the front-side substrate only by applying and curing the coating solution obtained from the metal alkoxide. Since the porosity and the like can be easily controlled, the visibility can be improved by reducing the reflection of the reflection type liquid crystal cell and the surface reflection of the front substrate.

Here, it is desirable to add an organic polymer to the coating liquid.

According to this means, by adding the organic polymer to the coating liquid, it is possible to easily and surely form pores having a size substantially corresponding to the molecular weight of the organic polymer. The effect of reducing reflection and surface reflection can be optimized by the type and amount of the organic polymer. Further, the apparent refractive index of the porous film can also be controlled by the type and amount of the organic polymer.

In these cases, it is preferable that the porous film is formed by adjusting the thickness and the porosity so as to reduce the surface reflectance of the front substrate.

According to this means, the apparent refractive index of the porous film can be changed by adjusting the porosity, and the interference effect can be changed by adjusting the thickness. By adjusting the ratio, the surface reflectance of the front substrate can be effectively reduced. Specifically, the porous film has an optical thickness of λ / 4 with respect to the light of wavelength λ, and has a refractive index of １ ／ of the refractive index of the front substrate.
If the power has an apparent refractive index, the surface reflectance can be made substantially zero.

[0028]

Next, an embodiment according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view showing a schematic structure of an embodiment of a liquid crystal device according to the present invention. A transparent electrode 11 made of ITO (indium tin oxide) is formed on an inner surface of a transparent substrate 10 made of non-alkali glass, and a polyimide (not shown) is formed thereon.
A transparent resin made of polyvinyl alcohol or the like is applied and fired to form an alignment film. The surface of the alignment film is subjected to a known rubbing treatment using a rubbing roller or the like. on the other hand,
On the inner surface of the transparent substrate 20, a reflective layer 21 made of a metal such as Al or Cr and a reflective electrode 21 serving as a pixel electrode are formed.
An alignment film similar to the above is formed thereon. The alignment film has been subjected to the rubbing treatment as described above.

On the inner surface of the transparent substrate 10, a wiring layer and a color filter are formed in addition to the transparent electrodes.
On the inner surface of the transparent substrate 20, a wiring layer, an active element, and the like are formed in addition to the reflective electrode. Transparent substrates 10 and 2
Numerals 0 are fixed in parallel with a predetermined interval via a sealing material to constitute a liquid crystal cell.

In the present embodiment, the composite liquid crystal layer 30 is sealed inside the above-mentioned liquid crystal cell.
, Liquid crystal molecules 31 and polymer particles 32 are dispersedly arranged. The composite liquid crystal layer 30 formed in the present embodiment is a polymer-dispersed liquid crystal layer in which a polymer is dispersed in liquid crystal.

The polymer-dispersed liquid crystal layer is formed by polymerizing a polymer precursor from a solution in which a liquid crystal and a polymer precursor are compatible, and phase-separating the liquid crystal and the polymer. preferable. On the other hand, as the liquid crystal, a nematic liquid crystal having dielectric anisotropy and refractive index anisotropy and other various liquid crystals can be used. As the liquid crystal, for example, a nematic liquid crystal to which a chiral component is added may have a twist angle in the composite liquid crystal layer. Twist angle is 90-1
In the range of 80 degrees, anisotropy occurs in the optical characteristics.
By giving a twist angle of 0 degree or more, anisotropy of optical characteristics can be reduced.

As the polymer precursor, various polymer precursors (monomer, prepolymer, etc.) that can be controlled in polymerization can be used. In particular, a side chain having a benzene skeleton or a biphenyl skeleton is added. As long as it is a thermoplastic polymer, a thermosetting polymer or a photocurable polymer, it can be widely used. For example,
Methacrylates or acrylates of biphenylmethanol or derivatives of these compounds can be used, and methacrylates or acrylates of naphthol or derivatives of these compounds can be used. Further, a mixture of the ester and a methacrylate derivative or acrylate derivative of biphenol may be used as the polymer precursor.

In the polymer-dispersed liquid crystal layer, it is preferable that liquid crystal molecules and polymer particles are aligned in the same direction in an initial state (in a state where no electric field is applied). In this case, it is desirable that the liquid crystal molecules and the polymer precursor in the solution are aligned in the same direction, and phase separation is performed while maintaining the alignment state during polymerization of the polymer precursor. By doing so, the refractive index of the composite liquid crystal layer can be reliably controlled, so that the optical characteristics of the composite liquid crystal layer can be improved.

Further, as the polymer, even if the polymer is formed by cooling and curing using a thermoplastic polymer precursor, heating or light irradiation may be performed using a thermosetting or photocurable polymer precursor. The polymerization may be carried out. However, in order to facilitate control in the manufacturing process and to prevent the influence on other materials, it is most preferable to use a photocurable polymer precursor and to phase separate the polymer particles by photopolymerization. It is effective. Particularly, polymerization by ultraviolet irradiation is the most practical method.

The optimal ratio of the liquid crystal contained in the composite liquid crystal layer is 50 to 97% by weight. If the liquid crystal content is less than this, it is difficult to respond to an electric field, and if it is more than this, the contrast is reduced.

In the present embodiment, after the above-described solution is injected into the liquid crystal cell, the polymer particles are polymerized and cured by irradiating ultraviolet rays to separate the phase from the liquid crystal.
And the polymer particles 32 form a composite liquid crystal layer 30 in which they are dispersedly arranged. In the composite liquid crystal layer 30 thus formed, as shown in FIG. 1, both the liquid crystal molecules 31 and the polymer particles 32 are in the same direction substantially parallel to the transparent substrates 10 and 20 (the rubbing direction of the alignment film). ).

When the liquid crystal device of this embodiment is in a state where no electric field is applied, as shown in FIG. 1, both the liquid crystal molecules 31 and the polymer particles 32 are substantially horizontally oriented, and the glass substrates 10 and 20 Is set so that the refractive index of the liquid crystal molecules 31 and the refractive index of the polymer particles 32 with respect to light in the viewing direction orthogonal to the above are substantially equal, so that the composite liquid crystal layer 30 becomes substantially transparent.

Next, in the liquid crystal device of the above embodiment,
When a voltage higher than the threshold in the composite liquid crystal layer 30 is applied between the transparent electrode 11 and the reflective electrode 21, the liquid crystal molecules 31 in the composite liquid crystal layer 30 are substantially aligned in the electric field direction, that is, in the vertical direction, as shown in FIG. I do. As a result, the composite liquid crystal layer 3
At 0, a difference occurs between the refractive index of the liquid crystal molecules 31 for light in the viewing direction and the refractive index of the polymer particles 32 for light in the same direction, so that light is scattered in the composite liquid crystal layer 30, It becomes cloudy.

Therefore, when no electric field is applied, the pixels of the liquid crystal device according to the present embodiment become almost transparent, and when the electric field is applied, the pixel becomes white due to light scattering. In this case, by appropriately changing the refractive index relationship between the liquid crystal molecules 31 and the polymer particles 32, light is scattered in a state where no electric field is applied,
It is also possible to make it transparent in the state where an electric field is applied.

In this embodiment, a surface layer 12 made of a substantially transparent oxide is formed on the surface of the transparent substrate 10 on the front side (viewer side). The surface layer 12 is a porous thin film formed by a method generally called a sol-gel method. The formation of the surface layer 12 is performed as follows.

First, the metal alkoxide M [OR] _n (M
Is a metal atom, R is a hydrocarbon group, n is any natural number) and alcohols (methanol, ethanol, propanol,
An alkoxide solution is prepared by mixing with an organic solvent such as pentanol and butanol), acetone, ethyl acetate, and dioxane, and water is mixed therein to induce a hydrolysis reaction. Here, you may mix a metal alkoxide, an organic solvent, and water simultaneously. As the hydrolysis proceeds, MOM
A compound having a bond is formed, and when the reaction proceeds further, the compound is polymerized into a gel.

As the metal M, any metal element other than Si can be used as long as it can form a transparent oxide. Usually, in addition to Si, Ti, Al, Ta and the like can be used alone. Can be used. Also, Si, Ti, A
1, Si, Ti, Al, Ta, Zn, N
a, Ca, B, K, La and the like can be added and mixed. In the following description of the present embodiment, an example using only Si will be described. Examples of metal alkoxides containing Si as a metal element include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and the like.

The coating liquid thus formed is applied on the surface of the transparent substrate 10. As a coating method, spin coating, dip coating, drain coating, spray coating, or the like can be used. In spin coating, the film thickness can be controlled by the rotation speed of the substrate and the viscosity of the coating liquid. In dip coating, the film thickness can be controlled by the viscosity of the coating liquid and the speed at which the substrate is pulled up. Contrary to dip coating, drain coating lowers the liquid level by flowing out the coating liquid from the tank in which the substrate is immersed.In this case, the film is coated by the viscosity of the coating liquid and the rate at which the liquid level decreases. The thickness can be controlled. In spray coating, the film thickness can be controlled to some extent by the viscosity of the coating liquid and the spray amount.

After the above coating solution is applied to the surface of the transparent substrate 10, the surface layer 12 as a transparent glass layer can be obtained by drying or heating to a temperature of 20 ° C. to 400 ° C. The surface layer 12 thus formed is a porous body having pores therein. The size of the pores is about 1 nm to 30 nm, but varies depending on the preparation conditions, and the amount of the pores also varies. Surface layer 12
The porosity and pore size of the organic solvent mixed in the metal alkoxide, the amount of water, the amount of water, the type and amount of an alkali catalyst such as ammonia, the acid catalyst such as hydrochloric acid, the type and amount of a base catalyst such as ammonium hydroxide, after coating It varies depending on the drying temperature.

The boiling point of the organic solvent contained in the coating liquid and the density or porosity of the produced glass have a negative correlation in most cases, and vary greatly depending on the drying temperature after coating. For example, tetramethoxysilane is used as a silicon alkoxide, and water and an organic solvent are mixed at a volume ratio of 1: 0.47, 1.18 to prepare a sol solution. After thoroughly mixing this solution, the coating solution gelled at room temperature is dried at 50 ° C. until there is no loss in weight, and finally dried at 120 ° C. to produce a dried gel. Here, as the organic solvent, methanol, ethanol, 2-propanol, and 1-propanol were used. For each of these solvents, pure water alone was used, and a hydrochloric acid catalyst (0.0001 mol / liter) was used. When the bulk density was measured for a sample containing ammonia and a sample containing an ammonia catalyst (0.01 mol / liter),
Regardless of the presence or absence of the catalyst, the results show that the lower the boiling point of the solvent, the higher the bulk density. In addition, when 1-pentanol, 1-butanol, or the like is used as the organic solvent, the results described above can be obtained. In this case, the pore diameter is about 1 to 3 nm, but the smaller the bulk density, the larger the pore diameter.

Further, there is a method of adding an organic polymer to the coating liquid in order to change the diameter and amount of the pores in the surface layer 12. Examples of the organic polymer to be added include polyethylene glycol monomethyl ether (PEGME), polyvinyl acetate (PVAC), hydroxypropyl cellulose (HPC), and glycerin. The addition of these organic polymers is performed within the surface layer 12 by 15 to 100 nm.
And larger pores.

For example, tetramethoxysilane is used as a silicon alkoxide, and water and methanol or ethanol as an organic solvent are mixed at a volume ratio of 1: 0.47, 1.18 to prepare a sol solution. Is added. Here, PEGME has a molecular weight of 500.
0, the addition amount is 5 wt%, and PVAC has a molecular weight of 150.
0, the addition amount is 5 wt%, and the HPC has a molecular weight of 3000.
00, and the added amount is 1.75 wt%. After thoroughly mixing this solution, the coating solution gelled at room temperature is dried at 50 ° C. until there is no loss in weight, and finally dried at 120 ° C. to produce a dried gel. As a result, the sample to which PEGME was added had a pore diameter peak at around 15 nm, the sample to which PVAC was added had a peak of pore size at around 50 nm, and the sample to which HPC was added had no clear peak. Is the entire measurement range 4 to 100
Distributed over 0 nm. As described above, when the organic polymer is added, many pores having a diameter substantially corresponding to the molecular weight of the organic polymer can be formed.

Here, 0 to 30 wt% of the organic polymer is added to the coating solution or the stock solution before the hydrolysis reaction.
It can be added in the range of about. In particular, in the present embodiment, in order to improve the visibility by reducing the reflection, it is desirable to add in the range of 5 to 20 wt%.

In order to control the porosity, pore diameter, pore density, etc. of the surface layer 12, it is also possible to use a mixture of silica fine particles in the coating liquid.

Next, the function and effect of the surface layer 12 will be described.

First, the porous surface layer 12 is placed on the front substrate 1.
By forming the reflective liquid crystal cell on the surface of the reflective liquid crystal cell of the above embodiment, the reflection of the background and illumination in the transparent state can be reduced by the optical action of the pores of the surface layer 12. The effect of preventing reflection is different depending on the density and the diameter of the pores of the surface layer 12, but as described above, it is necessary to optimize the conditions according to the formation conditions of the surface layer 12, the type and the amount of the organic polymer to be added, and the like. Can be.

Next, by forming the surface layer 12 on the surface of the front substrate 10, the reflectance of the front substrate 10 can be reduced. The surface layer 12 can be formed as an antireflection film by controlling its thickness and porosity.

Generally, the optical thickness of the coating is λ / 4, and the refractive index n _f of the coating and the refractive index n
When in the n _f = (n ₀₎ ^1/2 relationship between _0, the reflectivity of light at a wavelength λ becomes zero. The substrate is glass (n
₀ = approximately 1.5), there is usually no low-refractive-index solid material constituting the coating having such a relationship, and MgF ₂ or cryolite having a refractive index close to this is used. Can be On the other hand, when the porous surface layer 12 is formed of silicon oxide, an almost ideal refractive index of 1.22 can be obtained for the glass substrate. This is because the apparent refractive index n _p of a porous thin film is greatly affected by the porosity P according to the following equation.

N _p = (n ² −1) (1-P / 100) +1 Due to this property, in the case of titanium oxide (TiO ₂ ), when the porosity increases from 0% to 70%, the apparent refractive index becomes It decreases almost linearly from about 2.5 to about 1.7. In the case of aluminum oxide (Al ₂ O ₃ ), the porosity is from 0% to 7%.
Increasing to 0% increases the apparent refractive index from 1.7 to 1.4
To about a linear degree, and the silicon oxide (Si
In the case of O ₂ ), as the porosity increases from 0% to 70%, the apparent refractive index decreases almost linearly from 1.4 to about 1.2. Thus, it can be seen that especially silicon oxide can be used as an ideal low refractive index material for a glass substrate. In this case, the pore diameter of the surface layer 12 used for antireflection is preferably as small as 30 nm or less.

When the surface layer 12 also serving as an anti-reflection film is formed on the surface of the front substrate 10, for example, an aqueous solution of ammonium hydroxide concentrated in a mixed solution of tetraethoxysilane and anhydrous ethanol is added. After stirring at room temperature and aging for 3 days, a colloidal dispersion containing 3.0% of silica particles having a particle size of about 20 nm can be prepared, and this is used as a coating liquid. The coating liquid is applied to the surface of the substrate and then dried, whereby the surface layer 12 having a porosity of 50% and a refractive index of 1.22 can be formed. Since the thickness of the surface layer 12 can be changed depending on the number of times of application, the thickness is controlled to be λ / 4 in accordance with the wavelength λ of light to be in a non-reflection state. For example, based on the center wavelength of visible light (λ = 550 nm), the surface layer 1
It is preferable that the thickness of No. 2 be about 1000 to 1300 °.

As is well known, an antireflection film composed of a multilayer interference film can be formed by alternately laminating thin films having a high refractive index and thin films having a low refractive index. Therefore, it may be formed by a multilayer interference film in which the surface layers 12 are stacked. In this case, titanium oxide can be used as the high refractive index film, and magnesium fluoride, silicon oxide, or the like can be used as the low refractive index film. In this case, by making all the laminated thin films porous, in addition to the antireflection effect of the multilayer interference film, the effect of preventing reflection can be further enhanced by the laminated porous film.

In this embodiment, SiO ₂ , Al ₂ O ₃ ,
The surface layer 12 is a porous film made of a metal oxide such as TiO _2.
Is formed, the remarkable effect that in addition to the above-described effects, a high mechanical strength can be obtained and the manufacturing can be performed at low cost.

The present invention can be applied to a reflection type liquid crystal device (liquid crystal panel) as an electronic device.

For example, as shown in FIG. 3, a reflection type liquid crystal device is connected to a light valve (300R, 300G, 300B).
And can be applied to a projection display device (projector) using an optical system as shown in the figure.

FIG. 3 is a cross-sectional view on the XZ plane passing through the center of the optical element 130. The projector according to the present embodiment includes a light source unit 11 arranged along a system optical axis L.
0, integrator lens 120, polarization conversion element 130
Polarization illuminating device 100, which is roughly composed of
01, the dichroic mirror 412 that separates the blue light (B) component of the light reflected from the S-polarized light reflecting surface 201 of the polarizing beam splitter 200, and the separated blue light (B). A reflective liquid crystal light valve 300B that modulates blue light, a dichroic mirror 413 that reflects and separates the red light (R) component of the light beam after blue light is separated, and modulates the separated red light (R). Reflective liquid crystal light valve 3
00R, reflective liquid crystal light valve 300 that modulates the remaining green light (G) passing through dichroic mirror 413
G, three reflective liquid crystal light valves 300R, 300
The light modulated by G and 300B is composed by a dichroic mirror 412, 413, and a polarization beam splitter 200, and is composed of a projection optical system 500 composed of a projection lens that projects the composite light on a screen 600. The above three reflective liquid crystal light valves 300R, 300G, 3
00B uses the above-described liquid crystal panel.

The randomly polarized light beam emitted from the light source unit 110 is divided into a plurality of intermediate light beams by the integrator lens 120, and the polarization direction is substantially changed by the polarization conversion element 130 having the second integrator lens on the light incident side. After being converted into one kind of polarized light beam (S-polarized light beam), the light reaches the polarization beam splitter 200. The S-polarized light beam emitted from the polarization conversion element 130 is reflected by the S-polarized light beam reflection surface 2 of the polarizing beam splitter 200.
01, the blue light (B) of the reflected light is reflected by the blue light reflecting layer of the dichroic mirror 412 and modulated by the reflective liquid crystal light valve 300B. Also, dichroic mirror 411
Among the light beams transmitted through the blue light reflecting layer, the light beam of red light (R) is reflected by the red light reflecting layer of the dichroic mirror 413 and is modulated by the reflective liquid crystal light valve 300R. On the other hand, the luminous flux of the green light (G) transmitted through the red light reflecting layer of the dichroic mirror 413 is modulated by the reflective liquid crystal light valve 300G. Thus, each of the reflective liquid crystal light valves 300R, 300R
The color light is modulated by 0G and 300B.

Next, FIG. 4 is an external view showing an example of an electronic apparatus using the reflection type liquid crystal device (liquid crystal panel) of the present invention.

FIG. 4A is a perspective view showing a mobile phone. 1000 denotes a mobile phone body, of which 100
Reference numeral 1 denotes a liquid crystal display unit using the reflection type liquid crystal panel of the present invention.

FIG. 4B is a diagram showing a wristwatch-type electronic device. 1100 is a perspective view showing the watch main body. 11
Reference numeral 01 denotes a liquid crystal display unit using the reflection type liquid crystal panel of the present invention. Since this liquid crystal panel has higher definition pixels than a conventional clock display unit, it can also display television images, and can realize a wristwatch type television.

FIG. 4C is a diagram showing a portable information processing device such as a word processor or a personal computer. 1200 denotes an information processing apparatus, 1202 denotes an input unit such as a keyboard, 120
Reference numeral 6 denotes a display unit using the reflective liquid crystal panel of the present invention;
Reference numeral 4 denotes an information processing apparatus main body. Since each electronic device is a battery-driven electronic device, the use of a reflective liquid crystal panel without a light source lamp can extend the battery life. Further, since the peripheral circuit can be built in the panel substrate as in the present invention, the number of components can be greatly reduced, and the weight and size can be further reduced.

[0066]

As described above, according to the present invention,
By forming the light-transmitting porous film on the surface of the front-side substrate, the reflection of the background and illumination by the reflective layer can be reduced by the optical action of the pores of the porous film, Since the surface reflection of the front substrate can be reduced, the visibility of the liquid crystal device can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a liquid crystal cell of a liquid crystal device according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing an electric field application state of the embodiment.

FIG. 3 is a schematic diagram showing an application example of the present invention.

FIG. 4 is a schematic diagram showing another application example of the present invention.

[Explanation of symbols]

 10, 20 glass substrate 11 transparent electrode 12 surface layer 21 reflective electrode 30 composite liquid crystal layer 31 liquid crystal molecule 32 polymer particle

Claims (8)

[Claims] 1. A liquid crystal device having a liquid crystal layer between a pair of substrates and having a reflective layer on one of the pair of substrates,
A liquid crystal device having a porous film on a surface of the other substrate opposite to a surface on a liquid crystal layer side of the other substrate. 2. The liquid crystal device according to claim 1, wherein the porous film contains porous SiO ₂ as a main component. 3. The method according to claim 1, wherein the porous film is formed by applying and curing a sol-like coating liquid obtained by hydrolyzing a metal alkoxide. Characteristic liquid crystal device. 4. The liquid crystal device according to claim 3, wherein the porous film has a thickness and a refractive index that reduce surface reflection of the front substrate. 5. The liquid crystal device according to claim 1, wherein the liquid crystal layer is a composite liquid crystal layer in which liquid crystal and a polymer are dispersed and mixed. 6. A method for manufacturing a liquid crystal device having a liquid crystal layer between a pair of substrates and a reflective layer on one of the substrates, obtained by hydrolyzing a metal alkoxide on the surface of the one substrate. A method for manufacturing a liquid crystal device, wherein a porous film having a light-transmitting property is formed by applying a sol-like coating liquid and then performing a curing treatment. 7. The method for manufacturing a liquid crystal device according to claim 6, wherein an organic polymer is added to the coating liquid. 8. The porous film according to claim 6, wherein the porous film is formed by adjusting the thickness and the porosity so as to reduce the surface reflectance of the front substrate. Of manufacturing a liquid crystal device.