JPH0713146A - Liquid crystal display device and application device using the same - Google Patents

Abstract

(57) [Abstract] [Purpose] To modulate intense light with high efficiency. [Structure] A liquid crystal solidified composite 150 is sandwiched between a transparent front electrode 130 through which light enters and exits, a pixel electrode 170, and the like, and a first low refractive index thin film 25 from the back electrode substrate 160 side.
A multilayer light-shielding film 190 in which 0 and a first high-refractive-index thin film 240 are alternately laminated, and a multilayer reflective film 20 in which a second low-refractive-index thin film 230 and a second high-refractive-index thin film 220 are alternately laminated.
In the liquid crystal display element, a reflective functional layer 210 composed of 0 and 0 is formed, wherein Si, Ge, CdTe, CdS is formed on the first high-refractive-index thin film exhibiting light absorption.
e, at least one of PbTe, and SiO ₂ , MgF ₂ , Na ₃ AlF in the light-transmissive first low refractive index thin film.
₆ , at least one of CaF ₂ and TiO ₂ , Ta ₂ O ₅ , ZrO ₂ , HfO ₂ , Z in the second high refractive index thin film.
at least one of nS and S in the second low refractive index thin film.
At least one of iO ₂ , MgF ₂ , Na ₃ AlF ₆ , and CaF ₂ is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type projection type liquid crystal display device and a liquid crystal display element used therein.

[0002]

2. Description of the Related Art As a liquid crystal optical element, a liquid crystal optical element using a DSM (Dynamic Scattering) type liquid crystal was originally proposed, but in the DSM type, the current value flowing in the liquid crystal is high, so that the current consumption is high. It has the drawback of being large, and currently, TN (twisted nematic) type liquid crystal is mainly used, and it has appeared in the market as a pocket TV. The TN type liquid crystal has an extremely small leakage current and consumes less power, and thus is suitable for applications using a battery as a power source. However, since the polarizing plate is used, there is a drawback that the display is dark.

Furthermore, in recent years, nematic liquid crystals have been dispersed and held in a solidified matrix, and the refractive index of the solidified matrix is almost the same as the refractive index of the liquid crystal used when a voltage is applied or not applied. Attention has been paid to a transmission / scattering type liquid crystal optical element in which a liquid crystal solidified composite thus obtained is sandwiched. This transmission / scattering type liquid crystal optical element has an advantage that bright display is possible because no polarizing plate is used. Therefore, particularly when used in a projection type optical device, a bright projected image can be obtained, and therefore, it is attracting attention.

[0004]

When this transmission / scattering type liquid crystal optical element is used as a reflection type element by forming a light reflection layer on one surface of the element, light travels back and forth through the modulation material layer as compared with the case of using it as a transmission type element. The action length is twice as long, and as a result, the element has high scattering ability at the time of scattering. Therefore, when this transmission / scattering type liquid crystal optical element is used as a reflection type optical device, a significant difference between the transmission state and the scattering state occurs, and high contrast display may be possible as compared with the case of the transmission type optical device.

Further, when the active element and the storage capacitor are formed for each pixel, the reflection type eliminates the reduction of the pixel aperture ratio due to the formation of the storage capacitor, and a higher aperture ratio can be obtained as compared with the transmissive type. In addition to being easy, the degree of freedom in designing active elements such as TFTs is generally increased.

However, when it is used as a reflection type element, the light reflection layer formed on the back electrode substrate of the element is generally a metal film such as aluminum, which also serves as a pixel electrode. Such a metal film as a reflective electrode has a problem that it easily reacts with a base material and it is difficult to obtain a flat surface corresponding to an optical mirror surface. In particular, in the case of a TFT in which an insulating material such as SiN _x is used as the base, the flatness is significantly deteriorated.

As a result, there is a problem that the effective light reflectance is lowered due to the scattering of light due to the unevenness of the reflecting electrode. Further, there is a problem that the reflectance of a metal reflective film such as an aluminum electrode film is about 90% or less, and a portion of less than 100% is absorbed by the reflective film and converted into heat, which deteriorates element characteristics. Furthermore, the surface of the reflective electrode is likely to react with the liquid crystal layer, causing a problem that the reflectance of the reflective electrode decreases with time.

Therefore, as a back electrode substrate having a reflecting function of a reflection type transmission / scattering type liquid crystal optical element used in a projection type liquid crystal optical device, it has a flat surface as an optical reflecting mirror and little light absorption. High reflectivity and stability over time have been required. Further, in the case of a silicon semiconductor, which is a constituent material of an active element, when the incident light intensity is high, a photo-induced current is generated, which may deteriorate the image quality.

In order to reduce this photo-induced current, in a transmissive liquid crystal display element, a Cr light-shielding film is generally formed in a region corresponding to the active element portion of the front electrode substrate. However, in the case of a reflective liquid crystal display element, there is a problem that such a structure of the Cr light-shielding film causes the regular reflection light of the light-shielding film to be superimposed on the projection image and deteriorates the contrast ratio.

[0010]

The present invention has been made to solve the above problems, and provides a projection type liquid crystal display device having a bright and high contrast ratio and a liquid crystal display element used for the same.

First, a liquid crystal solidified composite in which a nematic liquid crystal is dispersed and held in a solidified matrix is sandwiched between a front electrode substrate having a transparent electrode and a back electrode substrate, and a voltage is applied or not applied. In either state, the refractive index of the solidified matrix is made to substantially match the refractive index of the liquid crystal used, and a reflective functional layer is provided between the back electrode substrate and the liquid crystal solidified composite. An element,
The electrode of the back electrode substrate includes a pixel electrode driven by an active element, and the reflection function layer has a structure in which a multilayer light shielding film and a multilayer reflection film are laminated from the back electrode substrate side. The high-refractive-index thin films and the first low-refractive-index thin films are alternately laminated, and the refractive index relatively changes in the film thickness direction of the multilayer light-shielding film. One of the low refractive index thin films of 1 is a light absorbing thin film, and the multilayer reflective film is a film of a multilayer reflective film in which a second high refractive index thin film and a second low refractive index thin film are alternately laminated. There is provided a first liquid crystal display element having a relative change in the refractive index in the thickness direction. In the above first liquid crystal display element, a substance having an absorption coefficient (imaginary part of complex refractive index) of 0.1 or more for an incident light wavelength is used as the light absorbing thin film,
As the first high refractive index thin film, a substance having a refractive index of 1.6 or more and 6.0 or less, preferably 1.8 or more and 5.6 or less with respect to an incident light wavelength is used, and a first low refractive index is used. The material having a refractive index difference of 0.2 or more, preferably 0.5 or more with respect to the refractive index of the first high-refractive-index thin film is used as the reflective thin film. A second high-refractive-index thin film is used as the second low-refractive-index thin film, using a substance having a refractive index with respect to wavelength of 1.6 or more and 4.0 or less, preferably 1.8 or more and 3.5 or less. There is provided a second liquid crystal display element, which uses a substance having a difference in refractive index with respect to the refractive index of 0.2 or more, preferably 0.4 or more.

In the above first or second liquid crystal display element, the light absorbing thin film is made of Si, Ge, CdTe,
There is provided a third liquid crystal display element using at least one selected from CdSe and PbTe. In the liquid crystal display device according to any one of the above first to third, as the second high refractive index thin film, TiO ₂ ,
At least one selected from Ta ₂ O ₅ , ZrO ₂ , HfO ₂ , and ZnS is used, and the second low refractive index thin film is selected from SiO ₂ , MgF ₂ , Na ₃ AlF ₆ , and CaF _2. There is provided a fourth liquid crystal display element, characterized in that at least one of the above is used. In addition, the first
~ In any one of the fourth liquid crystal display element, Si, Ge, CdTe, CdS as the first high refractive index thin film
e, PbTe, and at least one selected from the group consisting of SiO ₂ and MgF as the first low refractive index thin film.
Provided is a fifth liquid crystal display element, characterized in that at least one selected from the group consisting of ₂ , Na ₃ AlF ₆ , and CaF ₂ is used.

In addition, in the liquid crystal display element according to any one of the above first to fifth aspects, there is provided a sixth liquid crystal display element characterized in that the multilayer reflective film has wavelength selective reflectivity. Also, in the above-mentioned liquid crystal display element according to any one of 1 to 6, there is provided a seventh liquid crystal display element characterized in that the total thickness of the reflective functional layer is 1 to 5 μm. In the liquid crystal display element according to any one of the first to seventh aspects, the minimum transmittance of light transmitted through the reflective function layer is 0.0.
Provided is an eighth liquid crystal display element, which is 1% or less. In the liquid crystal display element according to any one of the above first to eighth aspects, the specific resistance of the reflective function layer is 10 ⁴ Ω.
Provided is a ninth liquid crystal display element having a size of not less than cm. Further, in the liquid crystal display element according to any one of the above first to ninth aspects, the front electrode substrate has a fine uneven surface at an interface with the liquid crystal solidified composite.
To provide a liquid crystal display device.

In the tenth liquid crystal display device described above, when the average interelectrode gap is G and the roughness of the unevenness of the front electrode substrate having the uneven surface is R _a , 0.03G <R _a <0 An eleventh liquid crystal display device is provided, which satisfies the relationship of 3G (1).

Furthermore, any one of the above first to eleventh aspects
Light from the light source optical system enters the liquid crystal display element inside the liquid crystal display element between the light source optical system and the projection optical system, and is reflected by the reflective function layer. A first projection type liquid crystal display device is arranged so that it is emitted from the front electrode substrate side and is projected by a projection optical system. Further, in the above-mentioned first projection type liquid crystal display device, a color separation / combination optical system is further provided, and the light emitted by the light source optical system is color-separated into a plurality of color separated lights by the color separation / combination optical system. Separated light is incident on different liquid crystal optical elements, and the color separated light reflected by the reflective function layer of each liquid crystal optical element is color-synthesized by the color separation / combination optical system and projected by a single projection optical system. A second projection type liquid crystal display device is provided. Furthermore, the reflective function layer of the liquid crystal display device has a reflection function layer of about 1 μm (0.8 μm
Wavelength band of 1.2 μm, preferably 0.9 μm to 1.1
The liquid crystal display element according to any one of claims 1 to 11 having a reflectance of 99% or more with respect to a laser beam of (μm) is provided between the light source optical system and the projection optical system, and the liquid crystal display element is provided by the projection optical system. An image of the liquid crystal display element is formed on the object to be irradiated by reducing and projecting the image of 1. to the object to be irradiated.

In the projection type liquid crystal optical device of the present invention, the liquid crystal optical element to be used has a transmission / scattering type operation mode in which a liquid crystal solidified composite capable of electrically controlling the scattering state and the transmitting state is sandwiched. In addition, a reflective liquid crystal optical element is used. Therefore, a polarizing plate is not required, a bright light source can be used, and the light transmittance at the time of transmission can be significantly improved.
Furthermore, since the light reflectance of the front electrode substrate is reduced, a high contrast ratio can be easily obtained.

In addition, the liquid crystal optical element sandwiching the liquid crystal solidified composite is subject to an alignment treatment essential for a reflection type TN (twisted nematic) type liquid crystal optical element and destruction of an active element due to static electricity generated at that time. Since problems can be avoided, the manufacturing yield of liquid crystal optical elements can be significantly improved.

Further, since this liquid crystal solidified composite is in the form of a film after solidification, problems such as short-circuiting between substrates due to pressurization of substrates and breakage of active elements due to movement of spacers are unlikely to occur.

Further, this liquid crystal solidified composite has a specific resistance equivalent to that of the conventional TN mode, and it is not necessary to provide a large storage capacitance for each pixel electrode as in the DS (dynamic scattering) mode. The active element provided in each pixel electrode can be easily designed, and the power consumption of the liquid crystal optical element can be kept low. Therefore, the manufacturing process is easy because the manufacturing process of the conventional liquid crystal optical element of the TN mode can be performed only by removing the alignment film forming process.

The specific resistance of the liquid crystal solidified composite is 5 ×
It is preferably 10 ⁹ Ω · cm or more. Further, in order to minimize the voltage drop due to leakage current or the like, the specific resistance is more preferably 10 ¹⁰ Ω · cm or more, and in this case, it is not necessary to give a large storage capacitance to each pixel electrode.

Further, in the case of the reflective liquid crystal display element of the present invention, the storage capacitor portion provided in parallel with the pixel electrode is covered with the reflective functional layer, and therefore the area corresponding to the capacitance value is the opening of the pixel electrode. Since the reduction of the rate is not caused, it is possible to form a larger storage capacitor than that of the transmissive liquid crystal display element. As a result, the specific resistance of the liquid crystal solidified composite was 5
Even with a voltage of about 10 ⁹ Ωcm, a high voltage holding ratio is easily achieved.

FIG. 3 is a schematic view showing the basic structure of the projection type liquid crystal optical device of the present invention. In FIG. 3, the light emitted from the light source 11 of the light source optical system 1 is condensed by the lens 51 and the like, passes through the lens 3 for collimating the light and enters the reflective liquid crystal display element 30, and the back electrode The light is reflected by the reflection function layer provided on the substrate side and emitted to the incident side, and the lens 3 again
After passing through the lens, the light enters the projection optical system 4, passes through the diaphragm 41 that reduces diffused light, and passes through the lens 42 of the projection optical system 4.
Is projected onto a screen (not shown).

Although the light source optical system of the present invention is simply shown in FIG. 3, an ellipsoidal mirror, a parabolic mirror, a spherical mirror, a lens, a cone-shaped prism, and the like are appropriately combined as the light source. Can be used as a light source optical system. Examples of the light source include a white light source such as a halogen lamp, a metal halide lamp, and a xenon lamp, and a monochromatic laser such as Nd: YAG (1064 nm). Furthermore, a cooling system may be added to the light source optical system 1, or an infrared cut filter, an ultraviolet cut filter, or the like may be combined. Further, the laser light may be expanded and collimated by a beam expander and used as incident light.

In the case where light is made incident on each of a plurality of liquid crystal display elements as color separation light, three color light sources may be prepared from the beginning, or white light source light is color separated by a dichroic mirror, a dichroic prism or the like. May be.
If specifically applied to the apparatus of FIG. 3, for example, if two dichroic mirrors are sequentially arranged between the light source optical system 1 and the lens 3 or between the lens 3 and the reflective liquid crystal display element 30. Good. In that case, three dichroic mirrors are used to support two colors of reflected light and transmitted light by the reflecting surfaces.
Three reflective liquid crystal display elements are arranged on one emission surface.

As the projection optical system 4, a conventional projection optical system composed of a lens or the like is used, but the projection optical system is used in combination with a device for reducing diffused light. This device for reducing the diffused light is a light that has passed straight through the liquid crystal display element and is reflected by the incident light (the liquid crystal solidified composite in the pixel portion is transmitted through the transparent portion and It suffices to take out the light that is regularly reflected by the reflection function layer) and reduce the light that has been reflected without going straight (light that is scattered in the portion where the liquid crystal solidified composite is in the scattering state). In particular, it is preferable to reduce the diffused light, which is the light reflected without going straight, without reducing the light that goes straight and is reflected.

This device for reducing the diffused light is combined with the projection optical system 4 as shown in FIG.
It may be placed before and after 42 or between the lenses. The device for reducing the diffused light is not limited to the aperture and the spot which are the diaphragms as described above, and may be, for example, a small-area mirror arranged on the optical path. Further, the focal length and aperture of the projection lens may be selected so as to remove diffused light without using a special aperture or the like.

In order to shorten the optical path length, it is also effective to incorporate a device for reducing diffused light in the projection optical system. In this case, the optical system becomes simpler and the size can be kept smaller than the case where the projection optical system and the device for reducing the diffused light are installed independently.

When a plurality of reflection type liquid crystal display elements are used, the projection optical system may project the emitted light separately, or may combine them into one and then project them. Good. However, it is preferable to combine and project the light beams into one, because the optical axis becomes one, so that the degree of freedom in use becomes large. In particular, as described above, when color separation is performed with a dichroic mirror or a dichroic prism for incidence, in the case of a reflective liquid crystal display element, the same dichroic prism can be used for combining emitted light, and there are few expensive parts. It will also be a big advantage. It also leads to downsizing of the projection type liquid crystal display device.

FIG. 1 is a sectional view of a reflective liquid crystal display element used in the projection type liquid crystal display device of the present invention. In FIG. 1, the unevenness 120 is a fine unevenness formed on the inner surface of the front electrode substrate 110. The transparent front electrode 130 is formed on the surface of the fine irregularities 120. Antireflection film 140 is a front electrode substrate
Formed on the outer surface of 110. The liquid crystal solidified composite 150 is located between the front electrode 130 and the multilayer reflective film 200. 160 is a back electrode substrate, 170 is a pixel electrode, 180 is an active element formed for each pixel electrode, 190 is a pixel electrode 170 and an active element
Reference numeral 200 denotes a multilayer light-shielding film in the reflection function layer 210 formed on the upper surface of 180, and reference numeral 200 denotes a multilayer reflection film further formed thereon.

The front electrode substrate 110 of the reflective liquid crystal optical element of the present invention is a transparent substrate such as glass or plastic,
On its inner surface, In ₂ O ₃ —SnO ₂ (ITO), SnO ₂
Etc. transparent electrodes are formed, and are usually solid electrodes. An antireflection film 140 is provided on at least the surface (surface on which light is incident) of the front electrode substrate 110. Preferably, antireflection films are provided on both surfaces.

This antireflection film 140 is formed of SiO ₂ , TiO ₂ , ZrO ₂ , Mg whose refractive index is adjusted with that of the substrate or electrode.
It is a single-layer or multi-layer interference film of an inorganic substance such as F ₂ , Al ₂ O ₃ , CeF ₃ or an organic substance such as polyimide. On the inner surface side, an antireflection film may be provided between the front electrode 130 and the liquid crystal solidified composite 150, or the substrate itself of the front electrode substrate 110 and the front electrode 130.
An antireflection film may be provided between and. Further, in relation to the multilayer antireflection film, the refractive index of the transparent front electrode 130,
You may adjust and use a film thickness.

Further, as shown in FIG. 1, a film having fine irregularities on the inner surface side may be used to prevent regular reflection due to scattering. In this case, the image sticking phenomenon due to the hysteresis peculiar to the liquid crystal solidified composite can be suppressed. This makes it possible to improve the image quality even in the halftone.

It is possible to reduce the hysteresis in the transmittance-voltage characteristics of the liquid crystal solidified substance composite and improve the display quality by optimizing the structure of the liquid crystal material, the solidified material and the liquid crystal solidified substance composite used. Becomes

When the transparent electrode is formed on the front electrode substrate 110 having fine irregularities as shown in FIG. 1, even if the liquid crystal solidified composite itself has some hysteresis,
It is possible to reduce the apparent hysteresis (or the optical problem caused by the hysteresis) to the extent that it does not cause a problem in the actual display. Therefore, as shown in FIG.
When 0 is formed as a concave-convex interface structure, the normal reflection of incident light is reduced and the visibility is improved, and the hysteresis is also reduced, so that the image quality is improved.

For the front electrode substrate 110, a lens or a dichroic prism for color separation / synthesis (having a refractive index similar to that of the front electrode substrate 110) described later is used as an optical adhesive or coupling oil. In the case of joining in, the interface reflection does not occur, and thus the antireflection film 140 is unnecessary.

The material of the back electrode substrate 160 is glass,
Any of plastic, metal, ceramic, semiconductor, etc. may be used. Further, since the reflective function layer 210 is further provided on the back electrode composed of the connection electrode and the pixel electrode 170, the back electrode material is not limited to a transparent electrode material such as ITO or SnO ₂ , but also aluminum or Cr. And other opaque electrode materials.

This back electrode is provided with a pixel electrode 170, which is used by being patterned so as to form a pixel, and an active element 180 such as a TFT (thin film transistor), a thin film diode or MIM is provided and connected. Alternatively, a single crystal silicon substrate may be used as the back electrode substrate 160, and the active element 180 may be formed for each pixel electrode 170.

FIG. 2 shows a structural example of the reflection function layer 210 (cross-sectional view in the film thickness direction). Pixel electrode 170 and active element 180
A multi-layer light-shielding film 190 is formed on the back electrode substrate 160 on which is formed, and a multi-layer reflective film 200 is further formed thereon.

A material transparent to incident light is used for the multilayer reflective film 200. Specifically, as the translucent high-refractive-index thin film 220 having a relatively high refractive index in the multilayer reflective film 200. T
At least one of the dielectrics of iO ₂ , Ta ₂ O ₅ , ZrO ₂ , HfO ₂ , and ZnS is used. In addition, as the low refractive index thin film 230 having a relatively low refractive index, SiO ₂ , Mg
At least one of the dielectrics of F ₂ , Na ₃ AlF ₆ , and CaF ₂ is used, and each of them is alternately laminated with an optical film thickness of optical wavelength order ( _nd = refractive index n × film thickness d). The multilayer reflective film 200 having the above structure and utilizing optical interference is formed.

Therefore, in the case of the same number of layers, the reflectance and the reflection wavelength band of the multilayer reflection film 200 become larger as the combination of materials having a large difference between high and low refractive indexes is large. Further, the larger the number of layers, the larger the reflectance. However, it is preferable that the total thickness of the multilayer reflective film is thinner as described later. Therefore, there is a practical thickness and number of layers. In order to use it as a reflective film, 80% or more of the required wavelength light,
More preferably, it is required to have a reflectance of 90% or more. When the above materials are used, a total film thickness of about 0.5 μm or more is required to satisfy this condition.

In the projection type liquid crystal display device of the present invention, when a general visible light full-color liquid crystal projector is constructed, in order to achieve a reflectance of about 98% in a specific wavelength region of the visible wavelength region, a dielectric The total thickness of the multilayer reflective film formed by the body can be achieved at about 1.5 μm.

When the central wavelength of the reflection wavelength band is λ, the maximum reflection at the wavelength λ is achieved by laminating the optical film thicknesses n and d of each layer of the multilayer reflective film made of a dielectric material to be λ / 4. Become a rate. In such a λ / 4 stack structure, the reflection wavelength band is limited. Therefore, in order to obtain a wider reflection wavelength band, it is effective to combine with a λ / 4 stack structure for different λ.

On the other hand, when a specific laser wavelength or white light is color-separated into three colors of RGB and made incident on the liquid crystal display element, a reflection wavelength band which is sufficiently required by a single λ / 4 stack structure is provided. Can be covered. As a result, a high reflectance can be obtained with a relatively thin total film thickness. In such cases,
The multilayer reflective film of the reflective functional layer preferably has wavelength selective reflectivity.

On the other hand, in FIG. 2, the multilayer light-shielding film 190 of the reflection function layer 210 is a high refractive index thin film having a relatively high refractive index.
It has a structure in which 240 and a low refractive index thin film 250 having a relatively low refractive index are alternately laminated with an optical film thickness n · d (refractive index x film thickness) in the order of light wavelength, and has a high refractive index. At least one of the thin film 240 and the low refractive index thin film 250 is a light absorbing thin film using a light absorbing substance. Although it has a light-absorbing function, the multilayer light-shielding film 190 as a whole also has a reflection function utilizing optical interference in the multilayer film, as with the multilayer reflective film 200. The light reaching the active element 180 on the back electrode substrate 160 is blocked by partially reflecting and partially absorbing the light transmitted without being reflected by the multilayer reflective film 200. The light absorption coefficient k (imaginary part of complex refractive index), which indicates the required degree of light absorption of the light absorbing thin film, is the incident light intensity, the photosensitivity of the active element (photoinduced current sensitivity), and the total film thickness. Depending on the allowable value of, but 0.1 or more,
Further, it is preferably 0.3 or more.

Si, Ge, CdTe, CdSe, PbT are materials that have both high refractive index and light absorption.
At least one of the substances e) is used as the light-absorbing high-refractive-index thin film 240, and SiO ₂ or M is used as a material having a refractive index relatively lower than that of the high-refractive-index thin film 240.
At least one of gF ₂ , Na ₃ AlF ₆ , and CaF ₂ is used for the light-transmitting low refractive index thin film 250.

It is generally difficult to achieve a high light-shielding rate of 1% or less with only a thin transparent dielectric multilayer film of 1 μm or less, but it is possible with the above-mentioned film structure. Become. In the above description, the case where the light-absorbing thin film is a high-refractive index material has been described, but the light-absorbing thin film may be a low-refractive index material. It is preferable that all the substances that form the multilayer light-shielding film are light-absorbing substances because a high light-shielding degree with respect to electronic circuit blocks such as active elements can be achieved.

As described above, the light-absorbing high refractive index thin film 24
Even if a single layer of 0 is formed, the light-shielding function can be obtained, but in order to achieve a sufficient light-shielding degree, the film becomes a thick film, which causes a problem of applied voltage loss described later. With the above structure, light that has passed through the multilayer reflection film 200 without being reflected is reflected by optical interference in the multilayer light-shielding film 190, and at the same time absorbs light and has a high refractive index thin film 240 (and / or a low refractive index). Due to the absorption in the light-transmitting thin film 250), a multi-layer light-shielding film having a high light-shielding degree that achieves a small transmittance as a whole with a small total film thickness is obtained as compared with the case where a single layer of the light-absorbing thin film is formed.

As in the case of the multilayer reflection film 200 using a dielectric, if the central wavelength of the reflection wavelength band is λ, then the multilayer light-shielding film
By laminating the optical film thickness nd of each layer of 190 to be λ / 4, the maximum reflectance is obtained at the wavelength λ and the light shielding function is exhibited in a wide wavelength band.

Since the voltage generated by the active element is applied between the front and back electrodes, it is distributed according to the dielectric constants of the reflective function layer and the liquid crystal solidified composite layer. Therefore, in order for the voltage to be effectively applied to the liquid crystal solidified composite itself,
The larger the electric capacity of the reflective functional layer is, the more preferable. That is, the thinner the total film thickness and the larger the dielectric constant, the more preferable.
Specifically, the total film thickness of the reflective functional layer is preferably 1 to 5 μm.

Since the reflective functional layer is uniformly formed on the image display portion of the liquid crystal display element, when a conductive material is used,
The voltage generated by the active element of each pixel electrode is blocked and is not sufficiently applied to the liquid crystal solidified composite layer. Therefore, the multilayer film material used for the reflective functional layer should not be a conductive material.

The higher the specific resistance is, the more preferable it is, but it is necessary that the specific resistance is at least 10 ⁴ Ω · cm or more. Si, Ge, CdSe, C used as a light-absorbing thin film
Since substances such as dTe and PbTe are semiconductors, high specific resistance like an insulator cannot be obtained. Therefore, impurities are mixed into the film-forming target in order to increase the specific resistance. Alternatively, it is effective to take measures such as forming the film in an atmosphere containing oxygen or nitrogen.

The transmittance of the reflective functional layer is determined to have an appropriate value depending on the degree of photo-induced current of the active element formed on the back electrode substrate and the amount of incident light. The minimum transmissivity of the reflective functional layer is 0.1 in order to prevent deterioration of image quality even when a high illuminance of 100,000 lux or more is incident on the liquid crystal display element by using an amorphous silicon TFT with a relatively large amount of photoinduced current. It is preferably 01% or less. Amorphous silicon TFT
When a polycrystalline silicon TFT with less photo-induced current is used, the total minimum film thickness of the reflective functional layer can be reduced because the minimum transmittance of the reflective functional layer can be a relatively large value.

The multilayer light-shielding film and the multilayer reflective film of the reflective function layer are
Although each constituent material is different, since film formation can be performed continuously in the same process, productivity is high. For example, in a film forming method such as high-frequency magnetron sputtering, vacuum deposition, ion plating, etc., the entire laminated film is formed in the same batch by sequentially using a plurality of targets in the same chamber. As a property of the film quality itself, film formation by a manufacturing method such as sputtering or ion plating is preferable.

Next, the structure of the projection type liquid crystal display device will be described. In FIG. 3, a color separation / combination system such as a dichroic mirror and a dichroic prism is arranged between the light source optical system 1 and the reflective liquid crystal display element 30 and between the projection optical system 4 and the reflective liquid crystal display element 30 to emit white light. RGB
When full-color display is performed using three reflective liquid crystal display elements separated into three colors, the multilayer reflective film of the reflective function layer of each liquid crystal display element 30 is the same reflective film having no wavelength selective reflection property. However, it may be a separate reflection film that reflects only the RGB wavelength bands.

In the former case, there is no difference in the structure of each substrate, which is preferable in manufacturing a liquid crystal display element. In the latter case, the total film thickness of the reflective function layer can be made smaller than that in the former case, so that the applied voltage loss is reduced.

A reflecting mirror formed of a multilayer film using a dielectric material can obtain various spectral characteristics by changing the structure of the multilayer film, and has a high degree of freedom in design, so that it is a dichroic mirror or dichroic used in a color separation / synthesis system. Even if the color purity is insufficient with only the prism, there is an advantage that the effect of the filter for correcting the color purity is exhibited.
This is effective when used as an individual reflecting mirror that reflects only each wavelength band of GB.

In the present invention, in the full-color projection type liquid crystal display device, the light from the white projection light source system is separated into the three colors of RGB by the dichroic mirror or the dichroic prism, and the reflection function of the three reflection type liquid crystal display elements. It is preferable that the color-separated lights reflected by the layers are color-synthesized by the same dichroic mirror or dichroic prism and then projected onto the screen by a single projection optical system.

With such a structure, the same dichroic mirror or dichroic prism can be used for the color separation / synthesis system as compared with the case of using the transmissive liquid crystal display element, and therefore the projection type liquid crystal display is used. The size of the entire device can be reduced.

Further, in the liquid crystal display element of the present invention, it is not necessary to form the light-shielding film only at the position corresponding to the active element on the front electrode substrate side or the back electrode substrate side, so that the aperture ratio due to the formation of the light-shielding film is reduced. The decrease is suppressed and the productivity is greatly improved because there is no patterning step. Next, the operation of the projection type liquid crystal display device of the present invention will be described in the case of using a liquid crystal display element in which a liquid crystal solidified composite in a scattering state is sandwiched in the state where no voltage is applied.

In the pixel portion in the transmissive state of the reflection type liquid crystal display element, light is transmitted, reflected by the reflection film (regular reflection) and emitted. This straight light is a light that passes through a device that reduces diffused light, and thus is displayed brightly on the projection screen. On the other hand, light is scattered at the pixel portion in the scattered state and is emitted as diffused light. Most of this light will not be able to pass through the device that attenuates the diffuse light, so it will appear dark on the projection screen.

In the present invention, since the liquid crystal display device of the reflection type is used, in the pixel portion in the scattering state, the light that reaches the back side without being scattered is reflected and passes through the scattering portion again. As a result, a high scattering rate is obtained in the thin liquid crystal solidified composite layer. Further, when the same scattering ability is used for the transmissive liquid crystal display element, the liquid crystal solidified substance composite layer can be made thin, so that the driving voltage can be reduced.

In the present invention, a liquid crystal solidified substance composite is composed of a solidified substance matrix having a large number of fine pores formed therein and a liquid crystal filled in the pores thereof, and either when a voltage is applied or when no voltage is applied. In that state, the refractive index of the solidified matrix is made to substantially match the refractive index of the liquid crystal used. In this case, it is preferable to use a liquid crystal solidified substance composite in which the refractive index anisotropy Δn of the liquid crystal used is 0.18 or more. In particular, it is preferable to use a nematic liquid crystal having a positive dielectric anisotropy so that the refractive index of the solidified matrix thereof substantially matches the ordinary refractive index (n _o ) of the liquid crystal used.

This liquid crystal solidified composite is used as a front electrode substrate, and a back electrode substrate side having a reflective function layer in which a multilayer light shielding film and a dielectric multilayer reflective film are laminated on a substrate on which pixel electrodes and active elements are formed. It is sandwiched between the two to form a reflective liquid crystal display element. The refractive index of the liquid crystal changes depending on the state of voltage applied between the electrodes of this reflective liquid crystal display element, and the relationship between the refractive index of the solidified matrix and the refractive index of the liquid crystal changes, and When they match, they are in a transmissive state (light is emitted after regular reflection), and when they are different in refractive index, they are in a scattering state (diffused light is emitted).

The liquid crystal solidified substance composite composed of the solidified substance matrix in which a large number of fine pores are formed and the liquid crystal filled in the pores is such that the liquid crystal is contained in a liquid bubble such as a microcapsule. Although it is a structure, individual microcapsules do not have to be completely independent, and liquid bubbles of individual liquid crystals may communicate with each other through a slit like a porous body.

The liquid crystal solidified substance composite used in the reflection type liquid crystal optical element of the present invention is prepared by mixing the liquid crystal and the curable compound constituting the solidified substance matrix to form a solution or latex. The solidified substance matrix may be separated by performing photo-curing, heat-curing, curing by removing the solvent, reaction curing or the like so that the liquid crystal is dispersed in the solidified substance matrix. This curable compound is preferably a photocurable or thermosetting type because it can be cured in a closed system. In particular, the use of a photocurable curable compound is preferable because it can be cured in a short time without being affected by heat.

As a concrete manufacturing method, a conventional ordinary TN is used.
A cell is formed using a sealing material as in the case of the liquid crystal optical element, and an uncured mixture of liquid crystal and a curable compound is injected from the injection port, and the injection port is sealed and then irradiated with light or heated. It can also be cured.

Further, in the case of the reflection type liquid crystal optical element of the present invention, for example, a liquid crystal and a curable compound are provided on one of the front electrode substrate and the back electrode substrate without using a sealing material. It is also possible to supply an uncured mixture, then stack the other electrode substrate and cure it by light irradiation or the like.

Of course, thereafter, a sealing material may be applied to the periphery to seal the periphery. According to this manufacturing method, the uncured mixture of the liquid crystal and the curable compound may be simply supplied by roll coating, spin coating, printing, coating with a dispenser, etc., so that the injection step is simple and the productivity is extremely high. Good.

The uncured mixture of the liquid crystal and the curable compound contains ceramic particles for controlling the substrate gap, plastic particles, spacers such as glass fibers, pigments, dyes,
Viscosity modifiers and other additives that do not adversely affect the performance of the present invention may be added.

By curing an element that is in a scattering state when no voltage is applied in such a state that a sufficiently high voltage is applied only to a specific portion during this curing step, that portion can be kept in a light transmitting state. Therefore, if there is something that is desired to be fixedly displayed, such a normal transmission portion may be formed. Conversely, in the case of an element that is in a transmissive state when no voltage is applied, the ordinary scattering portion can be similarly formed.

The higher the transmissivity of the reflection type liquid crystal display device using the liquid crystal solidified composite, the better the transmissivity, and the haze value in the scattering state is preferably 80% or more.

In the present invention, the refractive index of the solidified matrix (after curing) is the same as the refractive index of the liquid crystal used when the voltage is applied or the voltage is not applied. The index of refraction is not matched to that of the liquid crystal used. As a result, light is transmitted when the refractive index of the solidified material matrix and the refractive index of the liquid crystal match, and light is scattered (cloudy) when they do not match. The scattering property of this element is higher than that of the conventional DS mode reflective liquid crystal display element, and a display with a high contrast ratio can be obtained.

[0073] In the present invention, particularly, in a voltage applied state, the refractive index of the solidified matrix (after curing) is preferably made to coincide with the liquid crystal n _o used. As a result, since a transmissive state is achieved when a voltage is applied, the transmissivity at the time of transmitting light is increased and the light is uniformly transmitted, so that the display contrast ratio is improved.

The liquid crystal dispersed and held in the solidified matrix is preferably independent particles or particles in which some of them are connected. This is effective in achieving both high scattering power and high transparency when driven at a low voltage. Scattering is caused by the presence of an interface between the liquid crystal and the solidified matrix. Therefore, the larger the area of this interface, the higher the scattering property. In order to increase the area of this interface with a certain optimum liquid crystal particle diameter, it is important to increase the amount of liquid crystals independently separated from the resin, that is, increase the liquid crystal particle density.

However, when the amount of the liquid crystal separated from the solidified matrix is increased, the respective liquid crystal particles come to communicate with each other, and further, the liquid crystal comes to have a structure in which all the liquid crystal communicates with each other. The loss of the liquid crystal interface separated from the matrix leads to a decrease in the scattering ability.

Refractive index anisotropy Δn (= n _{e of} the liquid crystal used)
-N _o) is the contribution to scattering, obtain a high scattering property,
It is preferable that it is larger than a certain level, specifically, Δn>
0.18 is preferable, and Δn> 0.22 is particularly preferable.
Further, n _o of the liquid crystal used is preferably set to substantially match the refractive index of the solidified matrix (n _p), high transparency when an electric field is applied to obtain the time. More specifically, n _o -0.
03 <it is preferable to satisfy the relationship of n _p <n _o +0.05.

In order to improve the scattering property, it is effective to increase the volume fraction Φ of the operable liquid crystal of the liquid crystal solidified composite, and Φ> 20% is preferable, and the higher scattering property is obtained. Φ> 35% is preferred, and Φ> 4
5% is preferable. On the other hand, if Φ is too large, the structural stability of the liquid crystal-solidified composite deteriorates, so Φ <70% is preferable.

In the liquid crystal solidified substance composite of the reflection type liquid crystal display element of the present invention, since the liquid crystal molecules are aligned under the influence of the solidified substance matrix wall surface when no voltage is applied, they are not aligned in a fixed direction. . Therefore, when the refractive indexes of the two are different in this state, a scattering state (that is, a cloudy state) is shown.

When such a reflection type liquid crystal display element which shows a scattering state when no voltage is applied is used as a projection type display device, light is scattered in a portion having no electrode, and the portion other than the pixel portion of the back electrode is scattered. Even if the light shielding film is not provided, the light does not reach the projection screen and thus appears black. As a result, in order to prevent leakage of light from parts other than the pixels,
Since it is not necessary to shield the portion other than the pixel with a light shielding film or the like, there is also an advantage that the step of forming the light shielding film is unnecessary.

When the wiring electrode of the pixel is formed, a weak electric field is generated in the liquid crystal solidification composite layer between the counter electrode and incident light, and incident light passes through the liquid crystal solidification composite layer, and There may be a case where black is not displayed due to reflection on the electrodes. As a countermeasure, an antireflection film or a light absorption layer may be formed on the wiring electrode.

More preferably, by forming irregularities on the surface of the wiring electrode, the regular reflection light of the wiring electrode portion is reduced and made into scattered light, thereby reducing the incidence on the opening of the projection system.
As a result, black display is performed regardless of the voltage of the wiring section. In forming the unevenness on the surface of the wiring electrode, a metal surface such as aluminum or Cr as an electrode material may be directly used as the scattering surface, or unevenness may be formed on a patterned material such as a photosensitive resin or polyimide to form a refraction scattering surface. May be.

A voltage is applied between electrodes of desired pixels of this liquid crystal display element. In the pixel part where this voltage is applied,
Liquid crystal is arranged in parallel to the electric field direction, shows the transmission state by the liquid crystal n _o and n _p of solidified matrix coincide, becomes the light in the desired pixel is transmitted, it is displayed brightly on a projection screen It

When a TFT is used as an active element in the present invention, silicon may be suitable as a semiconductor material. In particular, since polycrystalline silicon has low photosensitivity like amorphous silicon, malfunction does not occur even if the light from the light source is not blocked by the light blocking film, and therefore it is preferable. When this polycrystalline silicon is used as a projection type liquid crystal display device as in the present invention, a strong light source for projection can be used and a bright display can be obtained.

In the liquid crystal display device and the liquid crystal display device of the present invention, an infrared cut filter, an ultraviolet cut filter or the like may be laminated, characters or figures may be printed, or a plurality of liquid crystal display devices may be provided. May be used.

Further, in the present invention, a protective plate such as a glass plate or a plastic plate may be laminated on the outside of the liquid crystal display element. As a result, even if the surface is pressed, the risk of damage is reduced, and safety is improved.

In the present invention, it is preferable to use a photocurable compound as the uncured curable compound constituting the above-mentioned liquid crystal solidified composite, and it is particularly preferable to use a photocurable vinyl compound. Specifically, a photocurable acrylic compound is exemplified. Particularly, those containing an acrylic oligomer which is polymerized and cured by light irradiation are preferable.

[0087] The liquid crystal used in the present invention may be a nematic liquid crystal, the liquid crystal such as refractive index of the solidified matrix agrees with the liquid crystal n _o is preferred. This liquid crystal
Although it may be used alone or as a composition, it can be said that it is advantageous to use the composition in order to satisfy various performance requirements such as operating temperature range and operating voltage.

When a photocurable compound is used, the liquid crystal used in the liquid crystal solidified substance composite preferably dissolves the photocurable compound uniformly, and does not dissolve the cured product after photoexposure. Alternatively, it is preferably made difficult to dissolve. Further, when the composition is used, it is preferable that the solubility of each liquid crystal is as close as possible.

In the case of producing a liquid crystal solidified composite, the substrate and the counter electrode substrate are arranged so that their electrode surfaces face each other like a conventional ordinary liquid crystal display element, and the periphery is sealed with a sealing material, The uncured liquid mixture for liquid crystal solidified composite may be injected from the injection port to seal the injection port, or the uncured mixture of the curable compound and the liquid crystal is supplied on one electrode substrate. Alternatively, the other electrode substrate may be laminated to manufacture.

In the liquid crystal display element of the present invention, a dichroic dye, a simple dye or a pigment may be added to the liquid crystal, or a curable compound colored may be used.

In the present invention, liquid crystal is used as a solvent in the liquid crystal solidified substance complex, and the photocurable compound is cured by photoexposure, so that it is not necessary to evaporate a simple solvent or water which is unnecessary at the time of curing. Therefore, since it can be cured in a closed system, the conventional manufacturing method of injecting into a cell can be adopted as it is, it is highly reliable, and it has the effect of adhering two substrates with a photocurable compound. Will be more likely.

By thus forming the liquid crystal solidified composite, the risk of short circuit between the upper and lower transparent electrodes is low, and
Unlike the normal TN type liquid crystal optical element, it is not necessary to strictly control the alignment and the substrate gap, and a liquid crystal display element capable of controlling the transmission state and the scattering state can be manufactured with extremely high productivity.

The ratio of the straight component and the scattered component reaching the projection screen can be controlled by the diameter of a spot, a mirror or the like, which is a device for reducing diffused light, and the focal length of a lens, to obtain a desired display contrast and display. It may be set so that brightness can be obtained.

When a device for reducing diffused light such as an aperture is used, it is preferable that the light incident on the liquid crystal optical element from the projection light source be more parallel in order to improve the display brightness and the contrast ratio. For that purpose, it is preferable to configure a light source optical system by combining a light source having high brightness and as close as possible to a point light source, a concave mirror, a condenser lens and the like. Therefore, it is effective to use a light source having a high directivity such as a laser beam in order to obtain more parallel light and to obtain a high contrast ratio.

Further, in the above description, the device for reducing the diffused light was mainly explained by the aperture and the spot, but it is possible to arrange a small mirror instead of the spot so as to take out only the necessary light.

Further, in the case of the reflective type as compared with the transmissive type, the back electrode substrate does not need to be a translucent material such as glass, and the degree of freedom in material selection is high. Further, a heat sink, a temperature controller such as a heater or a Peltier element may be installed on the surface of the back electrode substrate together with a thermometer to control the temperature of the liquid crystal solidified composite in the optimum operating temperature range.

The projection type liquid crystal display device of the present invention may be any one as long as the light from the light source for projection is incident on the reflection type liquid crystal display element and the reflected and emitted light is used. Therefore, it includes not only a display device that projects an image on a large-sized projection screen but also a reflective light modulator.

For example, in FIG. 3, as the incident light, the wavelength of pulse oscillation by the Q switch is about 1064 nm.
The d: YAG laser is used as the light source 11, and the liquid crystal display device 30 is used.
By reducing and projecting the reflected light on the object to be irradiated by using the projection lens 42, a laser marker or a laser processing device for printing the image on the liquid crystal display element 30 onto the object to be irradiated can be obtained. At this time, the reflective function layer of the liquid crystal display element 30 may have a reflective function and a light blocking function for light having a wavelength of only about 1064 nm.

[0099]

In the present invention, since the liquid crystal solidified substance composite is used for the reflection type liquid crystal display device, high scattering characteristics can be obtained even with the thin liquid crystal solidified substance composite, and the device itself has a high contrast ratio. Is obtained.

Further, since the dielectric multilayer reflection film is used as a constituent element of the reflection function layer, an optical reflection surface having extremely excellent flatness can be obtained and a high reflectance can be obtained as compared with the reflection film made of a metal film. As a result, a display with high brightness and high contrast ratio can be obtained.

Further, since the multilayer light-shielding film is used as a constituent element of the reflection function layer, it is possible to obtain a high light-shielding degree with a relatively thin film thickness, and the patterning is not required, so that the manufacturing process is simple. The yield is improved, the productivity is increased, and the large aperture ratio after forming the matrix-shaped active elements can be maintained.

Particularly, in the transmissive display element, the storage capacitor portion was a non-opening portion, but in the reflective display element according to the constitution of the present invention, it becomes an effective display portion, so that the effective aperture ratio is improved. Further, even when a liquid crystal solidified composite having a relatively low specific resistance is used, a large storage capacitance is formed, so that a high voltage holding ratio can be secured without lowering the aperture ratio.

Further, since the spectral reflectance can be arbitrarily adjusted according to the structure of the reflecting film formed of the dielectric multilayer film, a reflecting mirror having a high reflectance in the visible wavelength region to the infrared wavelength region can be obtained.

[0104]

【Example】

(Example 1) Glass substrate (Corning "705
9 ") was provided with an ITO transparent electrode on the surface and patterned as a pixel electrode, and three back electrode substrates were prepared in which a polycrystalline silicon TFT was arranged on the back electrode of each pixel.

On each of the back electrode substrates, as shown in FIG. 2, a high-refractive-index thin film 240 having a light-absorbing property of Si, which is a visible light-absorbing material having a refractive index of 3.4 and a light-absorption coefficient of 0.5, is provided. as the SiO ₂ having a refractive index of 1.45 as the optical transparency of the low refractive index thin film 250, alternately optical thickness n · d is λ / 4 (λ is the center wavelength of the incident light wavelength band, where lambda = 540 nm) and 10 layers were laminated. This gives 420
0.5 to 680 nm wide wavelength band transmittance 0.5
%, The multilayer light-shielding film 190 could be formed. This multilayer shading film
The total film thickness of 190 was about 0.7 μm.

Further, on such a multi-layered light-shielding film 190 formed, TiO ₂ having a refractive index of 2.35, which is a translucent dielectric material, is used as a high refractive index thin film 220, having a refractive index of 1.45. A low refractive index thin film 230 made of SiO ₂ was alternately laminated to form a multilayer reflective film 200. The optical film thickness is λ / 4 (here, λ =
It was possible to form a multilayer reflective film having a reflectance of 98% or more in a wide wavelength band of 490 nm to 600 nm by stacking 18 layers so as to have a thickness of 540 nm).

As a result, the multilayer-film reflective mirror 200 and the multilayer light-shielding film are formed.
Together with 190, a high light-shielding degree of 0.01% or less was achieved in a wide wavelength band of 490 nm to 600 nm. At this time, the total thickness of the reflective functional layer 210 was about 2.0 μm. This spectral characteristic is for Green, but the wavelength λ of the optical film thickness (λ / 4) of the multilayer-film reflective mirror 200 is used.
The conditions were changed to those for Blue and Red, and three reflective liquid crystal display elements each having a reflective film having a high light blocking degree for RGB colors formed were produced.

For film formation, a high-frequency magnetron sputtering apparatus is used to form a multilayer light-shielding film formed by alternately laminating SiO ₂ and Si, and SiO ₂ and TiO ₂ are continuously formed thereon.
Was alternately laminated to form a multilayer reflective film. As for the film structure, it is preferable that the refractive index changes “high / low / high / low” at all film interfaces. Even when the pixel electrode is made of ITO, or when an ITO protective layer (such as SiO ₂ or nitride film) is provided, this condition must be met with the film of the lowest layer with respect to those refractive index values. Is preferred because it enhances the overall reflective function.

When the reflection wavelength band of the multilayer reflection film using a dielectric covers the incident light wavelength band, the multilayer light-shielding film has a low light-shielding degree, and there is no problem. Specifically, the active element is amorphous silicon T with high photosensitivity.
In the case of FT, it is preferable that the combination of the multilayer reflective film and the multilayer light-shielding film has a transmittance of 0.01% or less in the wavelength band of incident light. Therefore, when the transmittance of the multilayer reflection film is 1% or less in the wavelength band of incident light, the transmittance of the multilayer light shielding film may be 1% or less. That is, it is possible to set the entire reflection function layer so as to assist each other in the relation of mutual combination.

On the other hand, when the active element is a polycrystalline silicon TFT having low photosensitivity, it is preferable that the combination of the multilayer reflective film and the multilayer light shielding film has a transmittance of 0.1% or less in the wavelength band of incident light. Therefore, when the transmittance of the light shielding film is 1% or less in the wavelength band of incident light, the transmittance of the multilayer reflective film may be 10% or less.

Moreover, by dispersing the wavelength λ in the visible wavelength range, instead of the 4 / λ alternating lamination having a simple optical film thickness,
A dielectric multilayer mirror having a reflectance of 90% or more can be formed in the visible wavelength band of 420 nm to 680 nm. At this time, since the total film thickness of the multilayer mirror is about 2 μm, a high light blocking rate of 0.01% or less in the visible wavelength band can be achieved by combining with the above-mentioned multilayer light blocking film having a film thickness of 0.7 μm. It was

Here, the light shielding film constitution of the interference multilayer film using Si as the non-metal substance film which is a material exhibiting the light absorption property in the visible light range is shown, but Ge or CdTe having a high refractive index is used instead of Si. If CdSe, CdSe, or PbTe is used, the same degree of light shielding can be achieved with a smaller film thickness. On the other hand, one surface of the same glass substrate is polished with a No. 1000 abrasive so as to reduce the regular reflected light and the transmitted light to an extremely small degree, thereby forming fine irregularities on the surface, and further the ITO transparent electrode thereon. Was formed. The average pitch of the irregularities obtained at this time is about 5
0 μm, the average depth of the irregularities is about 4 μm, and R _a is about 1
was μm.

Incidentally, R _a is JIS B 060.
1-1982 (ISO 468-1982) defines the center line average roughness.

A diameter of 1 is provided between the back electrode substrate and the front electrode substrate.
Spacers of 0 μm were scattered and the periphery was sealed with a sealing material to form a liquid crystal display device of three RGB as shown in FIG. The cell shape is diagonally 4.4 inches and the number of pixels is 480 vertical.
Number x 640 horizontal, each pixel size is 140μm x 140μ
It was m. Further, in this transmission / scattering type liquid crystal display element, it is not necessary to form the light-shielding film on the front electrode substrate, which was necessary in the conventional TN type liquid crystal display element. In the state of the liquid crystal display element, the pixel aperture ratio shows a high value of 58%.

Further, by forming a multi-layer reflection film of a dielectric multi-layer film to form a reflection type liquid crystal display element, the storage capacitor portion can also be used as an opening. For this reason,
A large aperture ratio of 67% was obtained. When using a conventional transmissive TN type liquid crystal display element with the same TFT configuration,
The aperture ratio remained as low as 40% due to the formation of the light-shielding film.

A nematic liquid crystal having a Δn of about 0.24 and a Δε of about 16 was uniformly dissolved in an acrylate monomer, a bifunctional urethane acrylate oligomer, and a photo-curing initiator, and the solution was injected into the cell. The composite material was cured to prepare three reflective liquid crystal display elements having a liquid crystal content of 68 wt%. When the applied voltage that gives a transmittance of 90% of the saturated transmittance is defined as a drive voltage, the drive voltage of each of these reflective liquid crystal display elements was 6V.

Then, a heat sink with a built-in heater to which a thermocouple for temperature measurement was attached was adhered from one surface of the back electrode substrate, and an air cooling fan was provided behind it. In an actual projection display state, the temperature of the thermocouple is monitored, and the heater is forcibly heated and air-cooled so that the temperature of each reflective liquid crystal display element is maintained within the range of 35 ° C ± 5 ° C. .

A plan view of the projection type liquid crystal display device of this embodiment is shown in FIG. 4, and a side view thereof is shown in FIG. In the side view of FIG. 5, the two sets of reflective liquid crystal display elements 31, 32 corresponding to the color light reflected and spectrally reflected by the dichroic mirror among the three sets of reflective liquid crystal display elements 31, 32, 33 are omitted.

As shown in FIGS. 4 and 5, a plano-convex spherical lens having a focal length of 180 mm is provided on each of the front electrode substrates of the three reflection type liquid crystal display elements 31A, 32A, 33A for RGB.
The plane sides of 31B, 32B and 33B were joined with an optical adhesive to obtain reflective liquid crystal display elements 31, 32 and 33. An antireflection film corresponding to each wavelength band is formed on the convex surface of the lens, and the reflectance is 0.
It is kept below 1%.

As the plano-convex spherical lens, a fiber array plate (FAP) having a structure in which optical fibers having EMA as a light absorbing material formed on the side surface of the clad are bundled may be used. In this case, the high-angle scattered light does not propagate in the fiber and is absorbed in the EMA, so that high contrast is achieved.

Next, the reflective liquid crystal display elements 31, 32, 33
, The light source system 1, the color separation / synthesis system 2, and the projection lens system 4 in FIG.
It was incorporated into a projection type device. In the light source optical system 1, a light source 11 was a metal halide lamp having a power of 150 W and an arc length of 5 mm, and the light was condensed by an elliptical mirror 12 with a cold mirror. The light emitting portion of the light source is arranged near the first focal point of the elliptic mirror, and the conical prism 14 is arranged near the second focal point of the elliptic mirror. The cone-shaped prism is oriented so that light enters from the bottom surface and exits to the apex angle side, and after processing and polishing the optical glass so that the apex angle is 60 °, an antireflection film is formed on the surface. .

Further, an aperture stop 13 having a variable aperture diameter is provided on the light emitting side of the cone-shaped prism. This cone-shaped prism has an effect of improving the unevenness of the light amount distribution on the surface of the liquid crystal display element due to the uneven light distribution which is likely to be generated when the arc light source is used. Although a conical prism, which is a transmissive optical element, is used here, a reflective conical object having a reflective film formed on the surface of the conical object may be used. In that case, the bisector of the apex angle is inclined with respect to the optical axis, and the optimum value of the apex angle is different from that of the transmission type.

In the optical system, the reflective liquid crystal display element 31,
If the average axis of the optical axis of the incident light to 32, 33 and the optical axis of the reflected light from the reflective liquid crystal display element is defined as the central optical axis 5, it is a flat dichroic type 2 for type 2 for color separation and synthesis. Mirror 2
1 and 22 intersect so that the angle between the perpendicular and the central optical axis 5 is 30 °, and the two dichroic mirrors 21 and 22 intersect so that the angle β formed by the mirror surfaces is 60 °. It was arranged one after another.

Further, the angle γ formed by the normal line of the reflection surfaces of the reflection type liquid crystal display elements 31, 32 and 33 and the optical axes of the incident light and the reflected light.
Was placed at an angle of 6 °. Further, the plane defined by the optical axis of the incident light and the optical axis of the reflected light on the reflection surface of the reflective liquid crystal display element and the plane defined by the perpendicular line of the two dichroic mirrors are arranged so as to be orthogonal to each other.

Next, the arrangement and configuration of the present embodiment, which provides a full-color projection type liquid crystal display device that is compact, lightweight and has high color purity, will be described.

That is, a full color projection type liquid crystal display device provided with a light source system for projection, a dichroic mirror for color separation / synthesis, three reflective liquid crystal display elements, a condenser lens and a projection lens is provided. The dichroic mirror for separation and synthesis is composed of a first flat plate type dichroic mirror and a second flat plate type dichroic mirror, and an angle α ₁ formed between the optical axis and the normal line of the first flat plate dichroic mirror surface.
Is 20 ° to 35 °, the angle α ₂ formed by the optical axis and the normal to the second flat plate dichroic mirror surface is 20 ° to 35 °, and the first flat plate dichroic mirror surface and the second flat dichroic mirror surface are The reflection type liquid crystal display element has a function of electrically controlling the transmission / scattering state, and is arranged so that the angle β formed with the flat plate type dichroic mirror surface on the horizontal plane is from 40 ° to 70 °. A reflective function layer composed of a multilayer reflective film and a multilayer light-shielding film is provided on the back electrode substrate side, and all three reflective liquid crystal display elements have an angle γ between the normal line of the reflective surface and the optical axis of 2 ° or less. The plane is arranged at 10 ° and is parallel to the plane defined by the optical axis of the incident light and the optical axis of the reflected light on the reflecting surface and the plane including the normal line of the first flat plate dichroic mirror, and Including the normal of the flat plate dichroic mirror The divergent light emitted from the light source is arranged so as to be substantially orthogonal to the plane parallel to the plane, and the divergent light emitted from the light source is color-separated by the action of the first flat plate type dichroic mirror and / or the second flat plate type dichroic mirror, and is divided into three color lights. Then, the light is emitted from either the first flat plate type dichroic mirror or the second flat plate type dichroic mirror, passes through a condenser lens provided for each color light, and is made into substantially parallel light, and then, for each color light. It is made incident on each corresponding reflection type liquid crystal display element and reflected by the reflection surface,
Each reflected color light is again condensed by each condenser lens,
First flat plate type dichroic mirror and / or second
There is provided a projection type liquid crystal display device (1) of three-dimensional arrangement type, which is characterized in that it is color-synthesized by the action of the flat plate type dichroic mirror to be projection light, and is further projected through a projection lens.

Here, it is not always necessary that α ₁ and α ₂ are exactly the same. The angle formed on the horizontal plane is defined as the angle when two flat plate type dichroic mirrors are projected on a certain plane, or the angle in the cross section on that plane. For example, it refers to the angle β appearing in the plan view of FIG. Of course, α ₁ and α ₂ may be equal to each other and may be commonly set to α.

In the three-dimensionally arranged projection type liquid crystal display device (1), the projection light source system is composed of a condenser mirror, a light source and an aperture stop, and an elliptical mirror is used as the condenser mirror.
The light-emitting portion of the light source is arranged near the first focus of the elliptical mirror, the aperture stop is arranged so that the opening of the aperture stop is located near the second focus of the elliptical mirror, and the reflective liquid crystal display element includes transparent electrodes. The nematic liquid crystal is dispersed and held in the solidified matrix between the front electrode substrate having the transparent electrode and the back electrode substrate having the transparent electrode, and the refraction of the solidified matrix in the state where the voltage is applied or not applied. It has a transmission-scattering type operation mode in which a liquid crystal solidified substance complex is sandwiched so that its refractive index substantially matches the refractive index of the liquid crystal used, and it is emitted from a light source and reflected and condensed by an elliptical mirror to form an aperture. The divergent light emitted from the aperture of the diaphragm is color-separated into three color lights by the action of the first flat plate type dichroic mirror and / or the second flat plate type dichroic mirror. Or a second flat plate type dichroic mirror, and after passing through a condensing lens provided for each color light, the light is converted into substantially parallel light, and then each reflection type liquid crystal display corresponding to each color light is displayed. The respective color lights that are made incident on the device and reflected by the reflecting surface are condensed again by the respective condenser lenses, and are color-synthesized by the action of the first flat plate type dichroic mirror and / or the second flat plate type dichroic mirror. A three-dimensionally arranged projection type liquid crystal display device (2) is provided which is projected as projection light and further projected through a projection lens.

In the projection type liquid crystal display device of this embodiment, as shown in FIG.
The red wavelength light R is the first dichroic mirror
The blue wavelength light B is reflected by the second dichroic mirror 22, the blue wavelength light B is reflected by the second dichroic mirror 22, and the green wavelength light G is transmitted. Regarding the spectral characteristics of the dichroic mirror, an edge type filter such as B reflection or R reflection has a higher degree of freedom in design than a notch type filter such as G reflection, and it is easy to improve color purity. And

The first dichroic mirror 21 has a reflectance of 50% and a color separation wavelength of 570 nm, reflects red (R) having a visible wavelength of 580 nm or more out of the light from the light source optical system, and transmits other wavelength light. The second dichroic mirror 22 has a long wavelength transmission type spectral characteristic as shown in FIG.
Has a wavelength separation wavelength of 500 nm, and has a short wavelength transmission type spectral characteristic that reflects blue (B) having a visible wavelength of 490 nm or less out of the light transmitted from the first dichroic mirror and transmits other wavelength light. The one which has was used. The light transmitted through the first and second dichroic mirrors was green (G).

As shown in FIG. 4, the light emitted from the light source optical system 1 becomes divergent light and the reflective liquid crystal display element 3
Since the light is emitted to 1, 32, and 33, the incident angle to the two types of dichroic mirrors 21 and 22 arranged between them is different depending on the in-plane position. That is, in the plan view of FIG.
In the dichroic mirror 21 of, the incident angle α becomes smaller toward the upper side of the dichroic mirror in the figure (α ₁ = α ₂ =
In the second dichroic mirror 22, the incident angle α has a smaller value toward the lower side of the dichroic mirror in the figure.

As described above, the film thickness distribution of the dielectric multi-layer film that determines the spectral characteristics of the dichroic mirror is set so that the spectral characteristics of the in-plane are the same even when the incident angles to the dichroic mirror are different in the plane. In the first dichroic mirror, the film is formed so as to be thicker on the lower side than on the upper side, and on the second dichroic mirror, the film is formed on the upper side as compared with the lower side.

Incident light and reflected light of the reflective liquid crystal display element are
Since the plan view of FIG. 4 passes through the same projecting light path, the influence of oblique incidence is the same for incident light and reflected light, and the spectral characteristics of the dichroic mirror are effective.

Further, in the side view of FIG. 5, the incident angles of the incident light and the reflected light of the reflection type liquid crystal display element are different, but the inclination angle of the angular dispersion center is 6 °, which is 30 ° in the plan view of FIG. Since it is small, it has little effect on its spectral characteristics. Therefore, it is sufficient to give the film thickness distribution of the dielectric multilayer film of the dichroic mirror in the in-plane direction in the plan view of FIG.

With such a constitution, the color purity of B and G is not a problem, but as it is, yellow (wavelength 575 nm to 595 nm) is mixed in R, so that a highly pure red color cannot be obtained and a red color close to orange is obtained. It was In particular, when a metal halide lamp is used, a strong emission line exists in this wavelength range, so that deterioration of the color purity of Green or Red becomes a problem.

Therefore, the red reflective liquid crystal display element 32 is used.
595 nm between the first dichroic mirror 21 and
It is preferable to arrange a filter having a long-wavelength transmission type spectral characteristic that transmits the above visible light wavelength and reflects light of at least 575 nm to 590 nm to improve the red color purity.

Aperture at the second focus position of the elliptical mirror of the light source optical system
The divergent light emitted from 13 is thus color-separated into RGB by the dichroic mirrors 21 and 22 for color separation / combination and the R filter, and then each reflection type liquid crystal display element.
Condenser lens 31B, 32B, bonded to 31A, 32A, 33A
Almost collimated light by 33B, reflective type liquid crystal display element 31A
, 32A, and 33A.

Then, the reflected light from the reflecting surface of the reflective liquid crystal display element is condensed again by the same condenser lens, and an image conjugate with the aperture at the second focus position of the elliptical mirror is at the second focus position of the elliptic mirror. It is generated at a position that does not overlap the opening.

The projection optical system is composed of a projection lens and a diffused light removing system. The diaphragm 41, which is a device for reducing diffused light, has a variable aperture diameter, and the inside of the projection lens 42 is composed of a plurality of lenses. The projection optical system 4 is arranged so that the image conjugate with the aperture 13 at the second focal position of the elliptic mirror corresponds to the variable diaphragm position of the projection lens. The projection optical system 4 including the diaphragm 41 as a component projects the light onto a projection screen (not shown).

At this time, the directivity of the incident light on the reflection type liquid crystal display element is determined by the divergence angle δ determined by the diameter Ψ of the variable aperture stop 13 of the light source optical system 1 and the focal length f of the condenser lenses 31B, 32B, 33B. _It can be expressed by ₁ (= 2 tan ⁻¹ (Ψ / 2f)). Further, the diameter Φ of the diffused light removing variable aperture stop 41 of the projection optical system 4, a condenser lens 31B, 32B, the focal length f of 33B is a spread angle of the directivity of the light projected converging angle [delta] ₂ Is determined.

Variable aperture 13 of light source optical system 1 and projection optical system 4
The variable throttle 41, the spread angle [delta] ₁ of the emitted light beam of the light source optical system
It is preferable to adjust and change the diameters of the respective openings so that the light collection angles δ ₂ are substantially equal to each other so that the light utilization ratio and the contrast ratio are not deteriorated.

Using the color projection type liquid crystal display device having such a configuration, the variable diaphragm 13 of the light source optical system and the variable diaphragm 41 of the projection optical system are changed under the condition of δ ₁ = δ ₂ to change the angle δ ₁ =
The contrast ratio and luminous flux on the projection screen were measured while changing δ ₂ . The results are summarized in Table 1 below.

[0143]

[Table 1]

When the room in which the projection screen is installed is bright, the amount of light at the black level of the image increases due to the influence of ambient light. Therefore, in order to obtain a high-contrast display with good visibility, the angle δ ₁ (= It is preferable to set δ ₂ ) to about 10 ° to 12 ° so that the projected light flux is large. On the other hand, if the room is dark, because without the effects of ambient light, with the light amount of the black level of the image is recognized directly, excessive screen brightness to reduce the visibility becomes glare, the angle [delta] ₁
It is preferable that (= δ ₂ ) is set to about 4 ° to 6 °, the contrast ratio is made high, and the black level gradation is reproduced.

By using the two variable apertures in this embodiment, it was possible to easily adjust the brightness and contrast ratio of the screen projection image according to the brightness of the surrounding environment. Further, the light amount distribution on the screen was highly uniform with 50% or more around the center and around the center, and the in-plane color distribution was also uniform. In addition, the RGB color purity of the projected image indicates a color purity of CRT or higher, and NT including the chromaticity coordinate of white is also included.
The standard color purity of SC was achieved.

In this embodiment, polycrystalline silicon having high light resistance is used as the active matrix, but amorphous silicon may be used. Alternatively, an active matrix in which a transistor is formed for each pixel on a silicon single crystal wafer may be used.

In this embodiment, a non-intersecting sequentially arranged dichroic mirror is used in the color separation / synthesis system. On the other hand, using a dichroic prism as a color separation / synthesis system, the divergent light emitted from the light source system is collimated by a convex lens and then incident on the dichroic prism, and after color separation into RGB,
It may be incident on each reflective liquid crystal optical element bonded to the three surfaces of the dichroic prism, and the reflected light may be again color-synthesized by the dichroic prism and then condensed and projected to the pupil position of the projection lens by the same convex lens. .

In this case, the cost becomes higher and the processing accuracy of the intersection is required to be high, but the angle adjustment is not necessary and the reflection type liquid crystal optical element is directly bonded to the interface without forming the antireflection film. There is an advantage that the reflection disappears.

(Comparative Example) In the reflective liquid crystal display element of Example 1, the reflective functional layer was composed of only the dielectric multilayer film reflecting mirror and no multilayer light shielding film was formed. As a result, a decrease in the projected light flux due to a decrease in the effective applied voltage to the liquid crystal solidified composite layer due to the generation of the photo-induced current in the TFT was observed. The degree was remarkable when the angle δ ₁ (= δ ₂ ) was 6 ° or more, and at 10 °, the luminous flux was reduced by about 15%. As a result, the contrast ratio also decreased accordingly.

Further, the amount of light incident on the display element is further increased to be 25 instead of the 150 W metal halide lamp 11.
When a 0 W metal halide lamp was used, the luminous flux in Example 1 simply increased by 1.67 times, but in this comparative example, both the luminous flux and the contrast ratio remained low.

(Embodiment 2) It has the same cell shape (diagonal 4.4 inches) and the number of pixels (480 vertical × 640 horizontal) as in the first embodiment, and the back electrode of each pixel is amorphous.
A back electrode substrate on which a silicon TFT is arranged was manufactured. Six layers of SiO ₂ and Si are alternately laminated on each back electrode substrate so that the optical film thickness (refractive index × film thickness) is λ / 4 (λ is Nd: YAG laser wavelength λ = 1064 nm). Thus, a light-shielding film having a transmittance of 1% or less at 1064 nm could be formed. At this time, the total thickness of the light shielding film was about 0.8 μm.

Further, SiO ₂ and TiO ₂ were alternately laminated on the light-shielding film thus formed to form a dielectric multilayer reflection film. By stacking 20 layers so that the optical film thickness (refractive index × film thickness) is λ / 4 (λ is Nd: YAG laser wavelength λ = 1064 nm), a reflective film having a reflectance of 99% or more at a wavelength of 1064 nm can be formed. It was As a result, in combination with the dielectric multilayer mirror and the light shielding film, a high light shielding degree of 0.01% or less at a wavelength of 1064 nm was achieved.

Amorphous silicon 1064
Since the photosensitivity at a wavelength of nm is 1/10 or less with respect to visible light, even if Nd: YAG laser light having high energy density is used as incident light, the liquid crystal optical element itself (in particular, precise electron such as active element) is used. The circuit) was not damaged.

On the other hand, as the front electrode substrate, the same transparent electrode glass substrate as in Example 1 was used. Spacers having a diameter of 10 μm are scattered between the back electrode substrate and the front electrode substrate, and the peripheral portion is sealed with a sealing material to form a single-plate liquid crystal display element, and the same liquid crystal solidified composite as in Example 1 is injected. It was formed by photopolymerization. However, unlike Example 1, the incident light is a near-infrared wavelength, so the exposure conditions were controlled so that the diameter of the liquid crystal particles was larger than that of visible light so that the scattering power was highest at a wavelength of 1064 nm.

In FIG. 3, an Nd: YAG laser light source is used as the light source 11 of the projection light source system, and the emitted spot-shaped laser light is a combination of two lenses, a concave lens and a convex lens 3 instead of the convex lens 51 shown in FIG. The Galileo-type afocal optical system by
Then, the liquid crystal display element 30 was irradiated with the light as it was spread to the effective surface of the liquid crystal display. The liquid crystal display element 30 is a convex lens for collecting light from the light source optical system 1.
It was placed immediately after collimated by 3.

Light incident on the liquid crystal display element 30 has an incident angle of 10
The light enters obliquely within an angle, is regularly reflected by the surface of the reflective film formed of the dielectric multilayer film, again enters the convex lens 3 for collecting light, and is condensed on the diaphragm 41 which is a device for reducing diffused light in the figure. Then, by the projection optical system installed behind the diaphragm 41,
The laser light is reduced and projected onto the object.

At this time, since the laser beam has high directivity,
Since the light is condensed into a small spot at the position of the diaphragm 41, which is a device for reducing the diffused light, the converging angle δ is set to 0.5 ° or less. The reduced image magnification of the liquid crystal display element 30 formed at the position of the irradiation target is the convex lens 3 for condensing and the projection optical system.
It can be changed arbitrarily in a combination of 4.

When the liquid crystal display element 30 has a rectangular shape,
In order to effectively use the laser light, it is preferable to use a cylindrical lens in the lens system before entering the liquid crystal display element so as to match the element shape. Further, a scanning optical element such as a polygon mirror may be provided between the laser and the liquid crystal display element in order to scan the reduced projection image on the position of the target object and perform multi-pattern irradiation.

Therefore, by using such an optical system and placing an absorber of 1064 nm light at the position of the object, the display pattern of the liquid crystal display element is printed or processed, and a laser marker, laser processing machine, laser solder, A laser welder or the like can be obtained. The laser light source may be an Nd.glass laser having an oscillation wavelength of about 1.06 μm or a semiconductor laser having an oscillation wavelength of about 0.84 μm.

Reference Example 1 Partial enlargement of Reference Example 1 of a projection type liquid crystal display device using a liquid crystal display device (three for each RGB color) having a multilayer reflection film and a multilayer light shielding film of the present invention and a dichroic prism. A plan view is shown in FIG. Liquid crystal optical element
Reference numerals 31-1, 32-1 and 33-1 are for separated color lights, and a multilayer reflection film and a multilayer light-shielding film corresponding to each color light are formed.

Furthermore, a side view of a projection type liquid crystal display device arranged in combination with a light source optical system 1X having a reflector 15 and a projection optical system 4X having a diaphragm 41 and a projection lens 42 is shown in FIG.
Shown in. Optical surface of dichroic prism 2X (21L and 22
(Consisting of M) has an intersection angle of 45 degrees. Also, the lens 3-1 is composed of one lens.

(Reference Example 2) A liquid crystal display device (three for each RGB color) having the multilayer reflective film and the multilayer light-shielding film of the present invention, and 4
FIG. 8 shows a plan view of a reference example 2 of a projection type liquid crystal display device which is used in combination with two dichroic mirrors which are arranged to intersect each other by 5 degrees.

A side view thereof is shown in FIG. The liquid crystal display elements 31-2, 32-2, 33-2 are for separated color lights, and a multilayer reflection film and a multilayer light-shielding film are formed for each color. Light source optical system 1Y having a light source 11, an elliptical mirror 12 and a diaphragm 13.
, Two dichroic mirrors 21 and 22 which are arranged at a 45 ° intersection with the lens 3-2, the above-mentioned three liquid crystal display elements, and the projection optical system 4.

[0164]

In the liquid crystal display element and the projection type liquid crystal display device of the present invention, the scattering state and the transmission state can be electrically controlled as the liquid crystal material sandwiched between the front electrode substrate and the back electrode substrate. Since a reflective liquid crystal display element sandwiching a liquid crystal solidified composite is used, a polarizing plate is not required, and the light transmittance at the time of transmission is significantly improved compared to the conventional TN type liquid crystal optical element. A bright projected image can be obtained.

The reflective liquid crystal display element used in the present invention can control high scattering property and high transmissivity by changing the voltage application state, and the substrate gap is larger than that used in the transmissive type. Can be driven at a low voltage because
Even in driving using a driving IC for a conventional TN type liquid crystal display element, a display having a high contrast ratio and high brightness can be realized.

In particular, in the present invention, since the multi-layer reflection film of the dielectric multi-layer film and the multi-layer light shielding film are used together as the reflection function layer provided on the back electrode substrate side, the optical mirror surface due to the reaction with the substrate interface material is formed. Problems such as deterioration are less likely to occur, and a flat mirror surface with high reflectance and no light absorption is easily obtained. Further, since it has no conductivity, there is no problem of short circuit with the wiring electrode.

Further, since the dielectric multilayer mirror and the multilayer light-shielding film block the incident light reaching the active element formed for each pixel electrode with a relatively thin film thickness, strong incident light is used. Even if an active element material having high photoinduced current sensitivity is used, stable display performance is obtained and the display quality as a liquid crystal display element is maintained. As a result, while making the most of the advantage of low voltage driving,
It is possible to obtain a projection display with a good contrast ratio.

Further, the multilayer light-shielding film which is a constituent element of the reflection function layer can be produced by using a film-forming process consistent with the multilayer-film reflecting mirror using the dielectric, and does not require fine processing such as patterning. High yield and suitable for mass production.

Further, since the multilayer light-shielding film is formed between the active element and the dielectric multilayer reflecting mirror, the aperture ratio does not decrease even though it is formed on the entire surface of the back electrode substrate. Strict light shielding is possible.

Since there is no restriction on the storage capacity formed for each pixel, a relatively large storage capacity can be formed.
A stable operation can be easily ensured in the design of the active element, and a high voltage holding ratio can be ensured even when a liquid crystal solidified composite having a relatively small specific resistance is used. In particular, even if the specific resistance of the liquid crystal-solidified composite is reduced due to the heat generation of the liquid crystal display element due to the radiant heat generated when the incident light of high illuminance is used,
There is no problem in operation due to sufficient storage capacity formation.

Further, since the reflective liquid crystal display element used in the present invention does not need to use a polarizing plate, the optical characteristics have little wavelength dependence, and the color correction of the light source is almost unnecessary. I also have. In addition, since problems such as rubbing and other alignment treatments essential to the TN type liquid crystal display element and destruction of the active element due to the generation of static electricity can be avoided, the manufacturing yield of the liquid crystal display element can be greatly improved.

Furthermore, since this liquid crystal solidified composite is in the form of a film after curing, problems such as short-circuiting between substrates due to pressurization of substrates and breakage of active elements due to movement of spacers are unlikely to occur.

Furthermore, the manufacturing process is easy because the manufacturing process of the conventional liquid crystal display device of the TN mode can be performed only by removing the alignment film forming process.

Further, the liquid crystal display element using this liquid crystal solidified composite has a feature that the response time is short,
It is easy to display moving images. Further, since the electro-optical characteristic (voltage-transmittance) of this liquid crystal display element is a comparatively gentle characteristic as compared with the liquid crystal display element of the TN mode, it can be easily applied to gradation display.

Further, since the reflection film formed of the dielectric multilayer film has almost no light absorption and is excellent in light resistance as used as a mirror for a resonator of a laser, it has high durability against high power laser light, It is possible to reduce the irradiation area of the reflection type liquid crystal display element and increase the laser power density to reduce the size. Depending on the band of incident light, each material and film thickness of the film of the reflective function layer including the multilayer reflective film and the multilayer light-shielding film can be appropriately adjusted, and the optical characteristics can be improved.

Further, since it also has a function as a protective layer for the active electrode and the active element, it is more preferable. In addition to the above, the present invention can be applied in various ways within a range that does not impair the effects of the present invention. For example, a reflection type optical modulator may be used.

[Brief description of drawings]

FIG. 1 is a sectional view showing a basic configuration of a liquid crystal display element of the present invention.

FIG. 2 is a sectional view showing a basic configuration of a back electrode substrate of the liquid crystal display element of the present invention.

FIG. 3 is a schematic diagram showing a basic configuration of a projection type liquid crystal display device of the present invention.

FIG. 4 is a plan view showing Embodiment 1 of the projection type liquid crystal display device of the present invention.

FIG. 5 is a sectional view showing the first embodiment of the projection type liquid crystal display device of the present invention.

FIG. 6 shows a liquid crystal display device of the present invention (three for each RGB color);
FIG. 6 is a partially enlarged plan view of Reference Example 1 of a projection type liquid crystal display device using a dichroic prism.

FIG. 7 is a diagram showing a liquid crystal display device of the present invention (3 pieces for each RGB color),
FIG. 9 is a side view of a reference example 1 of a projection type liquid crystal display device using a dichroic prism.

FIG. 8 is a view showing a liquid crystal display device of the present invention (3 pieces for each RGB color),
FIG. 9 is a plan view of a reference example 2 of a projection type liquid crystal display device which is used together with two dichroic mirrors arranged at 45 ° crossing positions.

FIG. 9 shows a liquid crystal display device of the present invention (3 sheets for each color of RGB);
FIG. 11 is a side view of a reference example 2 of a projection type liquid crystal display device which is used together with two dichroic mirrors arranged at 45 °.

[Explanation of symbols]

 1: Light source optical system 2: Color separation / synthesis system (dichroic mirror) 3, 51: Lens 4: Projection optical system 5: Central optical axis 11: Light source 13: Aperture 14: Conical prism 21, 22: Dichroic mirror 30, 31, 32, 33: Liquid crystal display elements 31A, 32A, 33A: Liquid crystal optical cells 31B, 32B, 33B: Condensing lens 41: Aperture 42: Projection lens 110: Front electrode substrate 120: Unevenness 130: Front electrode 140: Antireflection Film 150: Liquid crystal solidified composite 160: Back electrode substrate 170: Pixel electrode 180: Active element 190: Multi-layer light-shielding film 200: Multi-layer reflective film 210: Reflective function layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsuneo Wakabayashi 1160 Matsubara, Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa Prefecture AZ Technology Co., Ltd.

Claims (14)

[Claims] 1. A liquid crystal solidified composite in which a nematic liquid crystal is dispersed and held in a solidified matrix is sandwiched between a front electrode substrate having a transparent electrode and a back electrode substrate, and a voltage is applied or not applied. A liquid crystal having a reflective functional layer provided between the back electrode substrate and the liquid crystal-solidified composite such that the refractive index of the solidified matrix is made to substantially match the refractive index of the liquid crystal to be used in any state of time. In the display element, the electrode of the back electrode substrate includes a pixel electrode driven by an active element, and the reflective function layer has a structure in which a multilayer light-shielding film and a multilayer reflective film are stacked from the back electrode substrate side. The light-shielding film is formed by alternately stacking first high-refractive index thin films and first low-refractive-index thin films, and the refractive index relatively changes in the film thickness direction of the multilayer light-shielding film. One of the refractive index thin film and the first low refractive index thin film Is a light-absorbing thin film, and the multilayer reflective film has a second high-refractive-index thin film and a second low-refractive-index thin film alternately laminated, so that the multilayer reflective film has a relative refractive index in the film thickness direction. A liquid crystal display device characterized by being changed. 2. The liquid crystal display device according to claim 1, wherein a material having an absorption coefficient (imaginary part of complex refractive index) with respect to an incident light wavelength of 0.1 or more is used as the light absorbing thin film, and the first high refractive index is used. As the first thin film, a substance having a refractive index of 1.8 or more and 5.6 or less with respect to the incident light wavelength is used, and the first low refractive index thin film has a refractive index with respect to the refractive index of the first high refractive index thin film. Difference of 0.5 or more is used, and as the second high refractive index thin film, a substance having a refractive index of 1.8 or more and 3.5 or less with respect to the wavelength of incident light is used, and a second low refractive index A liquid crystal display element, wherein a material having a difference in refractive index of 0.4 or more with respect to the refractive index of the second high refractive index thin film is used as the index thin film. 3. The liquid crystal display device according to claim 1, wherein the light absorbing thin film is made of Si, Ge, CdTe, CdSe,
A liquid crystal display element comprising at least one selected from PbTe. 4. The liquid crystal display device according to claim 1, wherein the second high refractive index thin film is TiO ₂ , Ta ₂ O ₅ , Z.
At least one selected from rO ₂ , HfO ₂ , and ZnS is used, and SiO ₂ , MgF ₂ , Na is used as the second low refractive index thin film.
_At least 1 selected from ₃ AlF ₆ and CaF ₂
A liquid crystal display device characterized by using two. 5. The liquid crystal display element according to claim 1, wherein the first high refractive index thin film is Si, Ge, CdTe, C.
At least one selected from dSe and PbTe is used, and SiO ₂ , MgF ₂ , Na is used as the first low refractive index thin film.
_At least 1 selected from ₃ AlF ₆ and CaF ₂
A liquid crystal display device characterized by using two. 6. A liquid crystal display device according to claim 1, wherein the multilayer reflective film has wavelength selective reflectivity. 7. A liquid crystal display element according to claim 1, wherein the reflective functional layer has a total film thickness of 1 to 5 μm. 8. The liquid crystal display element according to claim 1, wherein the minimum transmittance of light transmitted through the reflection function layer is 0.01% or less. 9. The liquid crystal display element according to claim 1, wherein the reflective functional layer has a specific resistance of 10 ⁴ Ω · cm or more. 10. The liquid crystal display element according to claim 1, wherein the front electrode substrate has a fine uneven surface at the interface with the liquid crystal solidified composite. 11. The liquid crystal display device according to claim 10, wherein G is an average interelectrode gap and R _a is _a roughness of a front electrode substrate having an uneven surface, and 0.03G <R _a <0. . 3G (1) The liquid crystal display element characterized by satisfying the relationship. 12. The liquid crystal display device according to claim 1, wherein the light from the light source optical system is located on the front electrode substrate side of the liquid crystal display device between the optical paths of the light source optical system and the projection optical system. A projection type liquid crystal display device, wherein the projection type liquid crystal display device is arranged so as to enter the inside of the liquid crystal display element, be reflected by the reflection function layer, be emitted from the front electrode substrate side, and be projected by the projection optical system. 13. The projection type liquid crystal display device according to claim 12, further comprising a color separation / combination optical system provided between the light source optical system and the liquid crystal display element, wherein the light emitted by the light source optical system is color separation / combination optical system. The system separates the light into multiple color-separated lights, each color-separated light is incident on a different liquid crystal optical element, and the color-separated light reflected by the reflective function layer of each liquid-crystal optical element is color-synthesized by the color-separation / synthesis optical system. And a projection type liquid crystal display device which is projected by a single projection optical system. 14. The liquid crystal display according to claim 1, wherein the reflective functional layer of the liquid crystal display element has a reflectance of 99% or more for a laser beam in the vicinity of about 1 μm in the near infrared band. An element is provided between the light source optical system and the projection optical system, and the projection optical system reduces and projects the image of the liquid crystal display element onto the irradiation target, so that the image of the liquid crystal display element is formed on the irradiation target. Laser processing equipment characterized in that