JPH0534663A - Active matrix liquid crystal display element and projection type active matrix liquid crystal display device - Google Patents

Abstract

PURPOSE:To allow beautiful intermediate tone display which is well balanced in colors by decreasing after image development in the intermediate tone display of a liquid crystal optical element crimping a liquid crystal resin composite of a transmission scattering type. CONSTITUTION:The liquid crystal resin composite of the liquid crystal display elements 6A, 6B, 6C satisfies equations I, II. The particle sizes of the liquid crystal to the main wavelengths by each of respective colors, refractive index anisotropy, interelectrode spacings, etc., are unified. In the equations I, II, the refractive index anisotropy DELTAnx of the liquid crystal is >=0.18; the average particle size of the liquid crystal dispersed and held in the resin matrix is Rmum); the specific dielectric constant anisotropy of the liquid crystal is DELTAepsilonn; the elastic constant is K33(1<-12>N); the viscosity is (etaxcSt).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix liquid crystal display element and a projection type active matrix liquid crystal display device in which an active element is arranged for each pixel electrode.

[0002]

2. Description of the Related Art Liquid crystal displays have recently taken advantage of their features such as low power consumption and low voltage drive, and are used in personal word processors, handheld computers and pocket T's.
Widely used for V etc. Among them, an active matrix liquid crystal display element in which an active element is arranged for each pixel electrode is attracting attention and is being actively developed.

Initially, such a liquid crystal display device was manufactured by DSM.
A liquid crystal display element using a (dynamic scattering) type liquid crystal has also been proposed, but the DSM type has a drawback that it consumes a large amount of current because the current value flowing in the liquid crystal is high.
The liquid crystal using (twisted nematic) type liquid crystal has become the mainstream, and has appeared in the market as a pocket TV. T
The N-type liquid crystal has an extremely small leakage current and consumes less power, and is therefore suitable for a battery-powered application.

[0004]

When the active matrix liquid crystal display element is used in the DS mode, the leakage current of the liquid crystal itself is large. Therefore, there is a problem in that a large storage capacitor needs to be provided in parallel with each pixel, and the power consumption of the liquid crystal display element itself increases.

In the TN mode, since the leakage current of the liquid crystal itself is extremely small, it is not necessary to add a large storage capacity, and the power consumption of the liquid crystal display element itself can be reduced. However, the TN mode requires two polarizing plates and thus has a problem that the light transmittance is small. In particular, when performing color display using a color filter, only a few percent of the incident light can be used, and a strong light source is required, resulting in an increase in power consumption.

Further, when an image is projected, an extremely strong light source is required, and it is difficult to obtain a high contrast on the projection screen, and there is a problem that heat generation of the light source affects the liquid crystal display element. There is.

Therefore, in order to solve the problem of the TN mode,
A liquid crystal resin composite in which a nematic liquid crystal is dispersed and held in a resin matrix is used, and its scattering-transmission characteristics are utilized.
A mode that can be driven at a low voltage of 10 V or less has been proposed. However, when gradation display is performed, there is a problem that the responsiveness is poor particularly in a low voltage region (dark display region), and an afterimage is likely to occur.

In addition, when a plurality of active matrix liquid crystal display elements having the same structure are used for colorization, the transmission characteristics and the like differ depending on the color, so that the color balance is not sufficient and a particular color is visible. However, there is a problem that it is difficult to obtain a clear color display.

[0009]

The present invention has been made to solve the above-mentioned problems, and in particular, it is possible to obtain a display having a good color balance when performing color display, and a plurality of colors can be obtained. A projection type active matrix liquid crystal display device having a light source, a plurality of active matrix liquid crystal display elements on which light from respective color light sources is incident, and a projection optical system for synthetically projecting light emitted from the active matrix liquid crystal display element The nematic liquid crystal having positive dielectric anisotropy is dispersed and held in the resin matrix between the active matrix substrate in which the liquid crystal display element has an active element for each pixel electrode and the counter electrode substrate in which the counter electrode is provided, and The refractive index of the resin matrix is almost the same as the refractive index of the liquid crystal used when either An active matrix liquid crystal display device is formed by sandwiching a match so on have been liquid crystal polymer composite material, the average particle size of each color liquid crystal which is dispersed and held in a resin matrix R _x ([mu] m), the inter-electrode gap d _x ( μm), anisotropy of relative permittivity of liquid crystal Δε _x , elastic constant K33 _x (10 ⁻¹² N), viscosity η
_x (cSt), refractive index anisotropy Δn _x , and dominant wavelength λ _x (μm) of each color are Δn _x ² · Δε _x / (K33 _x · η _x )> 0.0011 (1) 4 (K33 _x / η _x ) ^0.5 > R _x > (K33 _x / Δε _x ) ^0.5 (2) is satisfied, and when at least one set of active matrix liquid crystal display elements is i ≠ j, Δn _i · R _i / λ _i ≈Δn _j・ R _j / λ _j (3) and satisfy the relationship of d _i / R _i ≈d _j / R _j (4), or Δn _i・ d _i ² / λ _i ≈Δn _j・ d _j A projection type active matrix liquid crystal display device characterized by satisfying a relationship of ² / λ _j (5).

In particular, the present invention provides a projection type active matrix liquid crystal display device characterized by satisfying the relationship of Δn _x ² · Δε _x / (K33 _x · η _x )> 0.0014 (1A).

Furthermore, the color light source is a color light source of RGB three colors, and x satisfies the expressions (1) and (2) for all three RGB colors, and Δn _R · R _R / λ _R ≈Δn _G · R _G / λ _G ≈ [Delta] n and _{B · R B / λ B (} 3A), d R / R R ≒ d G / R G ≒ d B / R B or satisfy the relation of (4A), ^{_{or, Δn R · d R 2 /}} λ there is provided a projection type active matrix liquid crystal display device which satisfies the relationship of ^{_{R ≒ Δn G · d G 2}} / λ G ≒ Δn B · d B 2 / λ B (5A).

Further, among them, the refractive index anisotropy Δ of the liquid crystal used in the active matrix liquid crystal display element.
When n _x is λ _i > λ _j , the projection type active matrix liquid crystal display device is characterized by satisfying the relationship of Δn _j ≦ Δn _i , and the refractive index difference of the liquid crystal used for each color. Projection type active matrix liquid crystal display, characterized in that both of the anisotropy Δn _x and the average particle diameter R _{x of the} liquid crystal retained in the resin matrix satisfy the relation of 0.2 <R _x · Δn _x <0.7 (6) The device, and further in them,
Average particle size R _x (μm) of liquid crystal of each color, interelectrode gap d _x , maximum effective applied voltage V _x (V) applied to liquid crystal resin composite
Is a projection type active matrix liquid crystal display device characterized by satisfying the relationship of 3R _x <d _x <9R _x (7) 0.6R _x · V _x <d _x <1.2R _x · V _x (8). It is provided.

Further, between an active matrix substrate having a color filter of three colors of RGB and having an active element for each pixel electrode and a counter electrode substrate having a counter electrode,
Nematic liquid crystals with positive dielectric anisotropy are dispersed and held in the resin matrix so that the refractive index of the resin matrix is almost the same as the refractive index of the liquid crystal used when voltage is applied or not applied. In an active matrix liquid crystal display device having a liquid crystal resin composite sandwiched between them, the average particle diameter R (μm) of the liquid crystal of each color dispersed and held in the resin matrix, the interelectrode gap d _x (μm), Relative permittivity anisotropy Δε, elastic constant K33 (10 ^-12 N), viscosity η (c
St), refractive index anisotropy Δn, and dominant wavelength λ _x (μm) of each color, Δn ² · Δε / (K33 · η) ＞ 0.0011 (1B) 4 (K33 / η) ^0.5 ＞ R ＞ (K33 / Δε) ^0.5 (2B) 0.2 <R · Δn <0.7 (6B) 3R <d _G <9R (7B), and at least 2 of the 3 RGB colors
An active matrix liquid crystal display device characterized by satisfying a relationship of d _i ² / λ _i ≈d _j ² / λ _j (5B), where i ≠ j in relation to color, and its active matrix liquid crystal display A projection type active matrix liquid crystal display device characterized in that a light source for projection and a projection optical system are combined with an element.

In the projection type active matrix liquid crystal display device of the present invention, the liquid crystal material sandwiched between the active matrix substrate and the counter electrode substrate is a liquid crystal resin composite capable of electrically controlling the scattering state and the transmitting state. Since the active matrix liquid crystal display element sandwiching the
No polarizing plate is required, and the light transmittance during transmission can be greatly improved. Furthermore, the average particle size R _X (μ
m) and the gap d _X (μm) between both electrodes are set for each color, so that when colors are mixed in the projection display, a color balance is good, a bright display with a good contrast ratio is obtained.

Further, the problems such as the alignment treatment essential for the TN type liquid crystal display element and the destruction of the active element due to the generated static electricity can be avoided, so that the manufacturing yield of the liquid crystal display element can be greatly improved.

Further, since this liquid crystal resin composite is in the form of a film after being cured, problems such as short circuit 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 resin composite has a specific resistance equivalent to that in the conventional TN mode, and it is not necessary to provide a large storage capacitance for each pixel electrode as in the DS mode, and the active element can be designed. It is easy and the power consumption of the liquid crystal display element can be kept low. Therefore, it is possible to manufacture the liquid crystal display device of the conventional TN mode only by removing the alignment film forming process from the manufacturing process, which facilitates the production.

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

As an active element provided on the pixel electrode,
There are transistors, diodes, non-linear resistance elements, etc.,
If necessary, two or more active elements may be arranged in one pixel. A liquid crystal display device is obtained by sandwiching the liquid crystal resin composite between an active matrix substrate having such an active element and a pixel electrode connected thereto and a counter electrode substrate having a counter electrode.

The liquid crystal display element of the present invention can be used as both a direct-view display element and a projection display element. When used as a direct-view display device, a display device may be configured by combining a backlight, a lens, a prism, a mirror, a diffusion plate, a light absorber, a color filter, etc., depending on the desired display characteristics.

The liquid crystal display element of the present invention is particularly suitable for a projection type display device, and can be combined with a projection light source, a projection optical system and the like to form a projection type liquid crystal display device.
A plurality of color light sources and a projection optical system are used as the projection type active matrix liquid crystal display device of the present invention. As these color light sources and projection optical systems, conventionally known projection optical systems such as projection light sources and lenses can be used. Normally, the plurality of liquid crystal display elements are arranged corresponding to the respective color light sources, and an image is synthesized by these. It is only necessary to project it by projecting.

As the color light source, a dedicated light source may be used for each color, or light from one light source may be dispersed and used. The light emitted from this color light source is made incident on the active matrix liquid crystal display element. In the present invention, these plural active matrix liquid crystal display elements are used with their characteristics matched for each color of the light source. Light emitted from these active matrix liquid crystal display elements is mixed and projected. As a result, a bright, well-balanced projection image with a high contrast ratio can be obtained.

In the present invention, the liquid crystal resin composite is composed of a resin matrix having a large number of fine pores formed therein and a nematic liquid crystal having a positive dielectric anisotropy filled in the pores.
The refractive index of the resin matrix is made to substantially match the refractive index of the liquid crystal to be used either when voltage is applied or not applied, and the refractive index anisotropy Δn of the liquid crystal to be used is 0.18 or more. It is preferable to use a liquid crystal resin composite. In particular, it is preferable that the refractive index of the resin matrix substantially matches the ordinary refractive index (n _o ) of the liquid crystal used.

The liquid crystal resin composite is sandwiched between an active matrix substrate and a counter electrode substrate to form a liquid crystal display element. The applied state of voltage between the electrodes of the liquid crystal display element changes the refractive index of the liquid crystal, and the relationship between the refractive index of the resin matrix and the refractive index of the liquid crystal changes. The state becomes a scattering state when the refractive index is different.

A liquid crystal resin composite composed of a resin matrix having a large number of fine pores and liquid crystals filled in the pores has a structure in which liquid crystals are contained in liquid bubbles such as microcapsules. However, 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 resin composite used in the liquid crystal display device of the present invention is prepared by mixing nematic liquid crystal and a curable compound constituting the resin matrix into a solution or a latex, which is photocured and heat-cured. The resin matrix may be separated by curing, curing by removing the solvent, reaction curing, or the like so that the nematic liquid crystal is dispersed in the resin matrix.

This curable compound is preferably a photo-curable or thermo-curable 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 specific manufacturing method, a cell is formed by using a sealing material as in the conventional ordinary nematic liquid crystal, and an uncured mixture of a nematic liquid crystal and a curable compound is injected from an injection port, and the injection port is injected. After sealing, the composition can be cured by irradiation with light or heating.

In the case of the liquid crystal display element of the present invention,
For example, an active matrix substrate in which an uncured mixture of a nematic liquid crystal and a curable compound is supplied onto a substrate provided with a transparent electrode as a counter electrode without using a sealing material, and then an active element is provided for each pixel electrode. Can be overlapped and cured 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 production method, the uncured mixture of the nematic 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 high. Very good.

The uncured mixture of the nematic 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 the like. You may add the additive which does not adversely affect the performance of.

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. On the contrary, in the case of the element which is in the transmissive state when the voltage is not applied, the ordinary scattering portion can be similarly formed.

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

In the present invention, the refractive index of the resin matrix (after curing) is the same as the refractive index of the liquid crystal used when the voltage is applied or not applied, and in the opposite state, the refractive index of the resin matrix is the same. , Is not matched with the refractive index of the liquid crystal used.

As a result, when the refractive index of the resin matrix and the refractive index of the liquid crystal match, the light is transmitted, and when they do not match, the light is scattered (clouded). The scattering property of this element is higher than that of the conventional DS mode liquid crystal display element, and a display with a high contrast ratio can be obtained.

In the present invention, the refractive index of the resin matrix (after curing) is made to match the ordinary refractive index (n _o ) of the liquid crystal used, particularly when a voltage is applied. preferable. 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.

An object of the present invention is to provide an optimum configuration of a projection type active matrix liquid crystal display device using an active matrix liquid crystal display element sandwiching this liquid crystal resin composite. In other words, the response is fast even in gradation display, display without afterimage is obtained, the color balance is good, the transmittance is high at the time of transmission, the high scattering property (light shielding property) at the time of scattering, and bright The present invention provides an active matrix liquid crystal display device having a large contrast ratio.

The factors that determine the electro-optical characteristics of the active matrix liquid crystal display device using the above liquid crystal resin composite are the refractive index (ordinary light refractive index n _o , extraordinary light refractive index n _e ) and relative permittivity of the liquid crystal used. (Ε //, ε⊥, // and ⊥ are parallel and perpendicular to the liquid crystal molecular axis), viscosity η, elastic constant K33,
And the refractive index n _{p of the} resin used, the relative dielectric constant ε _p , the elastic modulus, and the average particle diameter R _{x of} the liquid crystal dispersed and held in the resin matrix, the volume fraction Φ, the gap between the electrodes of the two substrates (liquid crystal resin The thickness) d _{x of} the complex, the maximum effective applied voltage V _x applied to the liquid crystal resin complex in the pixel portion by the active element, and the like.

Here, the liquid crystal average particle diameter R _x means the maximum diameter of the liquid crystal when the liquid crystal is an independent particle or a particle in which a part of the liquid crystal is in communication, and in the case of a structure in which most of the liquid crystal is in communication. Means the maximum diameter of the area where the orientations of the liquid crystal directors are correlated with each other.

The liquid crystal dispersed and held in the resin matrix is preferably independent particles or particles partially communicating with each other. 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 the liquid crystal / resin interface. 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 resin is increased, the respective liquid crystal particles come to communicate with each other,
Furthermore, all the liquid crystals come to have a structure in which they communicate with each other, which leads to the loss of the liquid crystal interface separated from the resin, leading to a decrease in the scattering ability.

In order to lower the driving voltage, it is important that the liquid crystals held in the resin have substantially the same driving electric field. For this purpose, it is advantageous for the liquid crystal to have a clear interface with the resin, and the loss of the interface leads to dispersion of the driving electric field, which tends to cause a decrease in contrast ratio and an increase in driving voltage. For this reason, it is preferable that the liquid crystal dispersed and held in the resin is independent particles that are present at a high density or particles that partially communicate with each other.

The electro-optical characteristics of the active matrix liquid crystal display device using the liquid crystal resin composite of the present invention have a high scattering property when no voltage is applied and a high transparency when a voltage is applied, that is, it is high. It is desirable to have a display contrast ratio. Using such a liquid crystal display element,
When projection type display is performed, display with high brightness and high contrast ratio can be obtained. In order to obtain such a display, it is necessary that the above factors have an optimum relationship.

Among these factors, the particularly important factor that determines the electro-optical characteristics of the active matrix liquid crystal display element is the refractive index of the liquid crystal used (refractive index anisotropy Δn = extraordinary light refractive index n _e −ordinary light refraction). Index n _o ), relative dielectric anisotropy of liquid crystal Δ
ε, viscosity η, elastic constant K33, average particle size R, particle size distribution, gap d _x between electrodes on both substrates, and dominant wavelength λ _{X of the} color light source.
Accordingly, the average particle diameter R of the liquid crystal and the interelectrode gap d _X of both substrates are determined and optimized for each liquid crystal display element.

Refractive index anisotropy Δn (= n _e − of the liquid crystal used
n _o ) contributes to the scattering property when no voltage is applied, and is preferably larger than a certain level in order to obtain high scattering property, specifically Δn> 0.18 is preferable, and Δn> 0.22 is particularly preferable. Further, it is preferable that the ordinary refractive index n _o of the liquid crystal used is substantially the same as the refractive index n _p of the resin matrix, and at this time, high transparency is obtained when a voltage is applied. More specifically, n _o -0.03
It is preferable to satisfy the relationship of <n _p <n _o +0.05.

The most important object of the present invention is to obtain an active matrix liquid crystal display element and a projection type active matrix liquid crystal display device which use a liquid crystal resin composite exhibiting a quick response even in gradation display and having a good color balance. That is. In the following description, the refractive index of the resin matrix, is to coincide with the ordinary refractive index of the liquid crystal used (n _o), is described with a liquid crystal display device comprising a transmissive state when a voltage is applied as an example.

Since the liquid crystal resin composite is driven in an off state and a sufficiently high on state (above the saturation voltage) when statically driven, it has a response of several tens of msec or less and is generally suitable for high-speed display. It is suitable. However, at the time of gradation display, a voltage lower than the saturation voltage is also used for displaying halftone, and there is a state in which the response is slower than that in static drive. The response during gradation display tends to be slower as the display on the low voltage side (darker display) becomes slower. Especially, the change from the OFF state to the low transmittance state is the slowest, and the number of responses during static drive It may be more than ten times slower.

The average particle diameter R of the liquid crystal dispersed and held in the resin matrix is a very important factor and contributes to the scattering property when no voltage is applied and the operating characteristics of the liquid crystal when a voltage is applied.

The important factors that determine the response during gradation display are the average particle size R of the liquid crystal retained in the resin, and
Its shape, relative dielectric anisotropy Δε of liquid crystal used, elastic constant
K33 (10 ^-12 N), viscosity η (cSt), etc.

The display without any afterimage can be obtained even in gradation display because the average particle size R _x (μm) of the liquid crystal dispersed and held in the resin matrix and the relative dielectric anisotropy of the liquid crystal used. Δε
_x , viscosity η _x (cSt), and elastic constant K33 _x (10 ^-12 N) are Δn _x ² · Δε _x / (K33 _x · η _x )> 0.0011 (1) 4 (K33 _x / η) for each color. It is the time when the relation of _x ) ^0.5 > R _x > (K33 _x / Δε _x ) ^0.5 (2) is satisfied.

In this range, the torque acting on the liquid crystal at each voltage during gradation display can be balanced, a display without afterimage can be obtained, and the electric field required for driving the liquid crystal can be suppressed low. The physical properties of the liquid crystal used here are values at room temperature.

The average particle diameter R _x of the liquid crystal dispersed and held in the resin matrix strongly depends on the responsivity, and when R _x becomes large, the response speed drops sharply. On the other hand, when R _x becomes smaller, the response speed becomes faster, but the voltage required for driving it becomes higher.

The optimum R _x region is determined by the balance of the electrostatic energy of the liquid crystal, the elastic energy, and the torque acting on the liquid crystal, and is used to obtain the response that does not hinder the display.
The upper limit of R _x is 4 (K33 _x / η) ^0.5 , and the lower limit is (k33 _x / Δε) ^0.5 .

The elastic constant of the liquid crystal determines the elastic energy accumulated in the liquid crystal, and in the liquid crystal resin composite, the bend energy due to the elastic constant K33 _x plays a large role, and the response characteristic, the driving characteristic, that is, the liquid crystal is greatly influenced. It is deeply involved with the working elastic torque. The relative dielectric constant anisotropy is related to the electric torque acting on the liquid crystal, that is, the voltage required for driving, and the viscosity is related to the viscous torque acting on the liquid crystal. It is the above-described relationship that the balance of these torques is optimized. Within this range, response characteristics suitable for displaying a moving image in gradation display can be obtained at a relatively low voltage.

In the case of a projection type active matrix liquid crystal display device which uses a plurality of color light sources and a plurality of active matrix liquid crystal display elements and synthesizes and projects those images, there is no afterimage in the halftone and the image can be driven at a relatively low voltage. For all active matrix liquid crystal display elements,
It is necessary to satisfy the formula (1). Above all, it is more preferable that the value of the formula (1) is larger than 0.0014. That is,
The expression (1) is preferably set as the following expression (1A). Δn _x ²・ Δε _x / (K33 _x・ η _x )> 0.0014 (1A)

Further, the refractive index anisotropy Δn _x of the liquid crystal, the relative dielectric constant anisotropy Δε _x , and the elastic constant K of the bend in each element.
33 _x (10 ^-12 N), viscosity η _x (cSt), average liquid crystal particle size R _x (μ
m) It is important that satisfies the _{4 (K33 x / η x)} 0.5> R x> (K33 x / Δε x) 0.5 (2).

In order to enhance the scattering property per unit operation liquid crystal amount, the active matrix liquid crystal display element of each color should satisfy 0.2 <R _x · Δn _x <0.7 (6).

When the average particle diameter R _x of the liquid crystal display device is smaller than the range of the expression (6), the response speed becomes faster, but the scattering ability per unit operation liquid crystal amount decreases and the voltage required for driving becomes Get higher On the other hand, when the average particle diameter R _x is larger than the range of the expression (6), it becomes possible to drive at a low voltage, but the scattering ability per unit operation liquid crystal amount decreases and the response speed becomes slow.

The particle size of the liquid crystal is preferably uniform. When the particle diameters are distributed, large liquid crystal particles lead to a decrease in scattering ability, and small liquid crystal particles lead to an increase in drive voltage, resulting in an increase in drive voltage and a decrease in contrast. The dispersion σ of the particle diameter is preferably within 0.25 times the average particle diameter, and within 0.15 times is more preferable. In addition,
The average particle size and the dispersion are the average and the dispersion weighted by volume.

In order to achieve a sufficient contrast, the interelectrode gap d _x (μm) is also important, and the average particle diameter R _x (
μm), the range satisfying the relation of 3R _x <d _x <9R _x (7) is desirable.

Further, in the case of multi-color display in one cell, that is, in the case of providing a plurality of colors in one cell, usually only one kind of liquid crystal can be used. Therefore, the above (1),
Equations (2) and (6) become the following equations (1B), (2B), and (6B). Δn ²・ Δε / (K33 ・ η) ＞ 0.0011 (1B) 4 (K33 / η) ^0.5 ＞ R ＞ (K33 / Δε) ^0.5 (2B) 0.2 <R ・ Δn <0.7 (6B)

The formula (1B) preferably satisfies the relationship of the formula (1C), as the formula (1) is preferably the formula (1A). Δn ² · Δε / (K33 / η) ＞ 0.0014 (1C)

Further, it is desirable that the range satisfying the relationship of 3R <d <9R (7C) is satisfied in the intermediate range of the wavelength used. RGB in one cell
If the three colors are provided, since intermediate region is green, it is sufficient to satisfy the relation _{3R <d G <9R (7B} ).

In the case of three colors of RGB, if the average particle size R _G of the liquid crystal display element is smaller than the range of the formula (6B), the scattering property has a wavelength dependency that the shorter wavelength side is stronger, Further, since a high voltage is required for the operation of the liquid crystal, there is a problem that power consumption increases. On the contrary, when the average particle size R _G is larger than the range of the formula (6B), although the wavelength dependency of the scattering property is small, the scattering property is weakened over the entire visible light region, the contrast ratio is lowered, and from the time of transmission. There is also a problem that the response to scattering is slow. Therefore, the above range is set.

In this case, the gap d _G between the electrodes of the liquid crystal display element with respect to the green light source is also an important factor. Increasing d _G improves the scattering property when no voltage is applied. However, if d _G is too large, a high voltage is required to achieve sufficient transparency when an electric field is applied, increasing power consumption and increasing T
There arises a problem that the active element for N and the driving IC cannot be used. Further, when d _G is made small, high transparency can be obtained at a low voltage, but the scattering property when no voltage is applied decreases. Therefore, in order to achieve both the scattering property when no voltage is applied and the high transparency when a voltage is applied, d _G (μm) is the same as described above (7B).
It is made to satisfy the formula.

Further, in order to make the characteristics of the respective colors uniform, in the liquid crystal display element as the object, Δn · R / λ and Δn · d ² / λ
Almost match. Specifically, the following is done. Δn _i・ R _i / λ _i ≈Δn _j・ R _j / λ _j (3) and d _i / R _i ≈d _j / R _j (4), or Δn _i・ d _i The relationship of ² / λ _i ≈Δn _j · d _j ² / λ _j (5) is satisfied.

Under the conditions of the expressions (3) and (4), the scattering intensity by the liquid crystal particles can be made almost uniform with respect to the color by adjusting the phase condition of the light, and in the off state or the halftone display state. It is possible to obtain a display having a good color balance by substantially equalizing the voltage transmittance characteristics. At the time of actual color display, a color display with a better color balance can be obtained by combining with fine adjustment by the drive circuit.

The characteristics for each color can also be made uniform by making the average particle diameter of the liquid crystal for each color constant and matching Δn _x · d _x ² / λ _x as in the formula (5). Therefore,
In a set of liquid crystal display elements whose characteristics are to be matched, (3), (4)
Color correction can be performed by either the relation of the formula or the relation of the formula (5).

When three or more liquid crystal display elements are used for three or more colors, some of them satisfy the relationships of equations (3) and (4), and some of them satisfy the relationship of equation (5). May be satisfied. Also, if there is little difference to be corrected among some of these colors, only between some of the colors that have a large effect (3),
It is also possible to perform color correction using the equation (4) or the equation (5).

Specifically, even in the case of RGB three colors, the best correction can be made by performing color correction between all three liquid crystal display elements by the formula (3), (4) or (5). Among the three liquid crystal display elements, between a pair of liquid crystal display elements,
The color correction may be performed by the formulas (3), (4), or (5).

Specifically, they are as follows, respectively. Δn _R・ R _R / λ _R ≈Δn _G・ R _G / λ _G and d _R / R _R ≈d _G / R _G , Δn _R・ R _R / λ _R ≈Δn _B・ R _B / λ _B , And d _R / R _R ≈d _B / R _B , Δn _G・ R _G / λ _G ≈Δn _B・ R _B / λ _B , and d _G / R _G ≈d _B / R _B Satisfying at least one set of relations, or Δn _R · d _R ² / λ _R ≈Δn _G · d _G ² / λ _G , Δn _R · d _R ² / λ _R ≈Δn _B · d _B ^At least one of the three relationships of ² / λ _B , Δn _G · d _G ² / λ _G ≈Δn _B · d _B ² / λ _B is satisfied.

When performing color correction for all three RGB colors,
Equations (3), (4), and (5) are as follows. Δn _R・ R _R / λ _R ≈Δn _G・ R _G / λ _G ≈Δn _B・ R _B / λ _B (3A) and d _R / R _R ≈d _G / R _G ≈d _B / R _B (4A ) Or Δn _R・ d _R ² / λ _R ≈ Δn _G・ d _G ² / λ _G ≈ Δn _B・ d _B ² / λ _B (5
Satisfies the relationship of A).

Even if all are color-corrected, RG is performed under the conditions of expressions (3) and (4), and GB is used in this case (5).
You may make it perform on condition of a formula.

Particularly, regarding the color correction among the three colors of RGB,
In general, the optical characteristics of red (R) are greatly different from the optical characteristics of green (G) and blue (B), so correction between R and G, B is most important. Therefore, for example, although the load on the drive circuit side increases, the same liquid crystal display element is used for G and B, and the correction between G and B is performed by the drive circuit.
The correction between R and G and between R and B may be performed in accordance with the relationship of the formula (3), (4) or (5). In this case, two types of liquid crystal display elements may be produced instead of three types of liquid crystal display elements as RGB liquid crystal display elements, which is an advantage in production.

Under the condition of the equation (5), although there is a slight disadvantage in terms of contrast ratio and the like from the equations (3) and (4), the scattering characteristics in each color can be almost equalized and the color balance can be maintained. It is possible to obtain a good display. In this case, when the liquid crystal used for each color is the same, the characteristics for each color can be almost equalized only by the gap between the electrodes, the manufacturing is easy, and by combining with the color filter,
It is possible to display a plurality of colors in a well-balanced color with one liquid crystal display element.

When the same liquid crystal is used and a color filter is also used, the equation (5) is set as i ≠ j and d _i ² / λ _i ≈d _j ² / λ _j (5B). When a color filter is used, a color-balanced display can be obtained by aligning the gaps between the electrodes in the color filter portion of each color according to the equation (5B).

Also in this case, when the three colors of RGB are used, the equation (5B) is as follows. d _R ² / λ _R ≈d _G ² / λ _G ≈d _B ² / λ _B (5C) However, also in this case, for example, between G and B, correction is not performed by the gap between the electrodes, and R and G and It is also possible to perform the correction only between R and B and perform the color correction between G and B by the drive circuit. In this case d _R ² / λ _R ≈ d _G ² / λ _G or d _R ² / λ
The ^{_{R ≒ d B 2 / λ B}} .

The liquid crystal particle diameter that maximizes the scattering intensity when off is deeply involved in λ and Δn, and as described above, ΔnR / λ
The scattering intensity per unit operation liquid crystal is determined by. Therefore, when trying to match the characteristics for each color using equations (3) and (4),
If the same liquid crystal is used for each color, it is necessary to increase the average particle diameter of the liquid crystal used on the longer wavelength side. Considering the characteristic that the response time becomes longer as the average particle size becomes larger,
In particular, the liquid crystal used on the longer wavelength side preferably has a larger Δn.

The liquid crystal to be used can be selected in consideration of the relationship between the viscosity, the elastic constant, the relative dielectric anisotropy and the average particle size shown in the equation (1). It is possible to obtain a moving image display in which the characteristics for each color are uniform according to the desired response characteristics, drive voltage, contrast ratio, and the like.

The refractive index anisotropy Δn of the liquid crystal used is
Is preferably Δn> 0.18 as described above,
When the liquid crystal is changed for each color, it is preferable to satisfy the above formula for each liquid crystal.

When the color balance is corrected under the condition of (3), (4) or (5), the refractive index anisotropy of each color is
It can be set within the above range, and λ _i > λ _j
In this case, it is preferable to satisfy the relationship of Δn _j ≦ Δn _i . Specifically, when three colors of RGB are used as the color light source, it is preferable that Δn _B ≦ Δn _G ≦ Δn _R.

The condition of Δn _B ≈Δn _G ≈Δn _R substantially equalizes Δn in the liquid crystal display elements of each color, and has an advantage that the same liquid crystal can be used for each element. In this case, the characteristics for each color can be corrected by the average particle diameter of the liquid crystal and the interelectrode gap by the equations (3) and (4), or by the interelectrode gap by the equation (5) or (5C).

Under the condition of Δn _B <Δn _G <Δn _R , since the liquid crystal of the liquid crystal display element used in the long wavelength region has a larger Δn, the structure of the liquid crystal resin composite and the gap between the electrodes are different for each color. It has the advantage that it does not need to be changed significantly. In particular, when Δn / λ is substantially the same for each color, it is possible to achieve color balance by using a liquid crystal resin composite having substantially the same structure and using substantially the same interelectrode gap.

Δn _B ≈Δn _G <Δn _R or Δn _B <Δn _G ≈Δn _R
The condition of 3 is that the characteristics of 3 colors are almost equalized by 2 kinds of liquid crystal, and the characteristics of each color are as follows: (3), (4) The average particle diameter of liquid crystal and the gap between electrodes, or (5) It is possible to correct by the gap between the electrodes by the formula

The absolute value of the gap d _X between the electrodes on both substrates may be selected so that the display brightness and the contrast ratio are optimal according to the applied voltage used. The maximum applied voltage and the gap between both electrodes are preferably set in the following ranges. 0.6R _x・ V _x <d _x <1.2R _x・ V _x (8)

Within this range, a display having a high contrast ratio can be achieved by using the conventional active element for TN and the driving IC. The setting of d _x within the range of equation (8) is
It can be set appropriately depending on the relationship between the relative anisotropy Δε (= ε // − ε⊥) of the liquid crystal used and the elastic constant. Generally, a liquid crystal with a large Δε (Δε> 5) is used,
It is preferable to maximize d _x within a range where sufficient transparency is obtained at the maximum effective applied voltage.

As described above, in the active matrix liquid crystal display device using the liquid crystal resin composite which is in the transparent state when a voltage is applied and is in the scattering state when no voltage is applied, the conditions of formulas (1) to (4) or (1) Liquid crystal display devices satisfying all of the conditions (3) and (5) have a voltage range of formula (8), that is, a conventional TN.
It is possible to display a projection-type color moving image having a high contrast ratio and being bright and having a good color balance by using an active element and a driving IC. Specifically, the contrast ratio is 100
As described above, it is possible to display with a transmittance of 70% or more when a voltage is applied and a response time of 200 msec or less during gradation display.

When the above-mentioned element is used as a reflection type, since light passes twice through the liquid crystal resin composite, the scattering property at the time of scattering increases. Therefore, within the range of the expression (7), d _x can be made thin and the maximum drive voltage determined by the expression (8) can be reduced.

Further, in order to improve the scattering property when no voltage is applied, it is effective to increase the volume fraction Φ of the operable liquid crystal of the liquid crystal resin composite, and Φ> 20% is preferable and higher scattering is achieved. Φ> 35% is preferable and Φ> 45% is more preferable to have the property. On the other hand, if Φ is too large, the structural stability of the liquid crystal resin composite deteriorates, so Φ <70% is preferable.

In the liquid crystal display element of the present invention, when a voltage is not applied, the liquid crystal is not aligned in a certain direction (aligned due to the influence of the resin matrix wall surface) and the difference in the refractive index between the resin matrix. , Shows a scattering state (that is, a cloudy state). Therefore, when used as a projection type display device like the present invention, light does not reach the projection screen even if a light shielding film is not provided on a portion other than the pixel portion, because light is scattered on the portion without electrodes. , Looks black. As a result, in order to prevent light from leaking from the portion other than the pixel electrode, it is not necessary to shield the portion other than the pixel electrode with a light shielding film or the like, and there is also an advantage that the step of forming the light shielding film is unnecessary. Have.

A voltage is applied to the desired pixel. In the pixel portion to which this voltage is applied, the liquid crystal is arranged in parallel with the electric field direction, and the ordinary state refractive index (n _o ) of the liquid crystal and the refractive index (n _p ) of the resin matrix match each other, thereby showing a transmissive state,
The light is transmitted through the desired pixel and is displayed brightly on the projection screen.

By curing this device 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 at all. If desired, such a normally permeable portion may be formed.

Further, the active matrix liquid crystal display device of the present invention can perform color display by providing a color filter. This color filter is
Three colors may be provided in one liquid crystal display element, one color may be provided in one liquid crystal display element, or three of these may be combined. This color filter may be provided on the electrode surface side of the substrate or may be provided on the outside. Further, color display may be performed by mixing a dye, a pigment or the like in the liquid crystal resin composite.

FIG. 1 is a schematic view of an example using a dichroic prism of a projection type active matrix liquid crystal display device of the present invention.

In FIG. 1, 1 is a light source, 2 is a concave mirror, and 3
Is a condenser lens, 4 is a spectroscopic dichroic prism, 5A, 5B, 5C and 5D are mirrors, and 1 to 5D constitute a color light source. 6A, 6B and 6C are active matrix liquid crystal display elements sandwiching a liquid crystal resin composite corresponding to each color, 7 is a combining dichroic prism, 8 is a projection lens, 9 is an aperture for removing other than straight light, 10 is projection It is a screen to do. The projection optical system is composed of 7-9.

FIG. 2 is a schematic view of an example in which the dichroic prism of the projection type active matrix liquid crystal display device of the present invention is not used.

In FIG. 2, 11 is a light source, 12 is a concave mirror, and 13
Are condenser lenses, 15A, 15B, and 15C are dichroic mirrors, and the color light source is composed of 11 to 15C. 16A, 16
B and 16C are active matrix liquid crystal display elements sandwiching a liquid crystal resin composite corresponding to each color, 18A, 18B and 18C are projection lenses provided for each color, and 19A, 19B and 19C are straight light beams provided for each color. Aperture for removing all but 20 is a screen for projection. The projection optical system is composed of 18A to 19C.

FIG. 3 is a sectional view of an active matrix liquid crystal display element used in the projection type active matrix liquid crystal display device of the present invention.

In FIG. 3, 21 is an active matrix liquid crystal display element, 22 is a glass or plastic substrate for an active matrix substrate, 23 is ITO (In ₂ O ₃ -SnO ₂ ),
Pixel electrode such as SnO ₂ , 24 is an active element such as a transistor, a diode and a non-linear resistance element, 25 is a glass or plastic substrate for a counter electrode substrate, 26 is a counter electrode such as ITO or SnO ₂ , 27 is both substrates 1 shows a liquid crystal resin composite sandwiched between.

When a three-terminal element such as a TFT (thin film transistor) is used as the active element of the present invention, the counter electrode substrate may be provided with a solid electrode common to all pixels, but a two-terminal element such as a MIM element or a PIN diode. In the case of using, the counter electrode substrate is patterned in a stripe shape.

When a TFT is used as the active element, silicon is suitable as the semiconductor material. In particular, since polycrystalline silicon has no photosensitivity like amorphous silicon, it does not malfunction even if the light from the light source is not shielded by the light shielding film, which 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.

Further, in the case of the conventional TN type liquid crystal display element, a light-shielding film is often formed between the pixels in order to suppress the leakage of light from between the pixels. The light-shielding film can be formed, and forming the light-shielding film on the active element portion does not significantly affect the whole process. That is, even if polycrystalline silicon is used as the active element and the light shielding film is not formed in the active element portion,
If it is necessary to form a light-shielding film between pixels, the number of steps cannot be reduced.

On the other hand, in the present invention, as described above,
The refractive index of the liquid crystal used is the ordinary refractive index (n
_o ) By using a liquid crystal resin composite that is made to substantially match with the above, light is scattered in areas where no voltage is applied and black is projected on the projected screen, so a light-shielding film is formed between pixels. You don't have to.

Therefore, when polycrystalline silicon is used as the active element, the polycrystalline silicon has low photosensitivity, and thus malfunction due to light is unlikely to occur. For this reason, the strictness of the light-shielding property is not required even if the light-shielding film is not formed in the active element portion, so that the step of forming the light-shielding film can be eliminated or simplified, and the productivity is improved.

Even if amorphous silicon is used,
It can be used by forming a light-shielding film on the semiconductor portion. The electrodes are usually transparent electrodes, but when used as a reflective liquid crystal display device, they may be reflective electrodes of chromium, aluminum, or the like.

In the liquid crystal display device and the liquid crystal display device of the present invention, an infrared cut filter, an ultraviolet cut filter and the like may be laminated, characters and figures may be printed, and a plurality of liquid crystal display devices may be used. 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, a photo-curable compound is also preferably used as the uncured curable compound constituting the liquid crystal resin composite, and a photo-curable vinyl compound is particularly preferably used. Specifically, a photocurable acrylic compound is exemplified, and a compound containing an acrylic oligomer that is polymerized and cured by light irradiation is particularly preferable.

The liquid crystal used in the present invention may be a nematic liquid crystal having a positive dielectric anisotropy, and a liquid crystal in which the refractive index of the resin matrix matches the ordinary refractive index (n _o ) of the liquid crystal. Preferably, the composition may be used alone or may be used, but 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 in the liquid crystal used in the liquid crystal resin composite, it is preferable that the photocurable compound is uniformly dissolved, and the cured product after photoexposure is not dissolved. Alternatively, it is considered to be difficult to dissolve, and when the composition is used, it is desirable that the solubility of each liquid crystal be as close as possible.

In the case of manufacturing a liquid crystal resin composite, the active matrix substrate and the counter electrode substrate are arranged so that their electrode surfaces face each other like a conventional normal liquid crystal display element, and the periphery is sealed with a sealing material. The liquid mixture for the uncured liquid crystal resin 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 may be supplied on one of the substrates. Alternatively, the other substrates facing each other may be stacked.

In the liquid crystal display device 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 resin composite, 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 using the liquid crystal resin composite as described above, there is a low risk of the upper and lower transparent electrodes being short-circuited, and the alignment and the substrate gap need to be strictly controlled as in a normal TN type display element. In addition, a liquid crystal display element capable of controlling the transmission state and the scattering state can be manufactured with extremely high productivity.

When the substrate of this liquid crystal display element is plastic or thin glass, it is preferable to laminate a protective plate of plastic or glass on the outside for protection.

In the liquid crystal display device of the present invention, when a voltage is applied for driving, the liquid crystal resin composite material between the electrodes of the pixels is usually equal to or less than the maximum effective voltage of the above formula (8). It may be driven so as to be applied to.

As the color light source, the projection optical system, the projection screen for projection and the like of the present invention, the conventional light source, projection optical system and projection screen can be used, and the active matrix liquid crystal of the present invention is provided between the color light source and the projection optical system. A display element may be arranged. In this case, the projection optical system may synthesize the images of a plurality of active matrix liquid crystal display elements using the optical system as shown in FIG. 1 and then project the images, or, as shown in FIG. The images of the display elements may be individually projected on the projection screen and combined on the projection screen.

Further, although the color light source is also used by being separated from one light source in the above-mentioned example, it is also possible to separately provide light sources of a plurality of colors and make them incident on the active matrix liquid crystal display element.

Light sources used for these color light sources include halogen lamps, metal halide lamps, xenon lamps, and the like, and a concave mirror, a condenser lens, and the like can be combined to increase the light utilization efficiency. Also, a cooling system can be added to this, or an infrared cut filter or an ultraviolet cut filter can be used in combination.
A TV channel display such as D may be added.

In particular, in the case of this projection type display, a device for reducing diffused light on the optical path, for example, 9 and 19 in FIGS.
Display contrast can be increased by installing apertures and spots as shown in A, 19B, and 19C.

That is, the device for reducing the diffused light is the light that goes straight to the incident light (light that passes through the portion where the pixel portion is in the transmission state) out of the light that has passed through the liquid crystal display element and does not go straight. Any light source capable of reducing (light scattered by the liquid crystal resin composite in the scattering state) may be used. In particular, it is preferable to reduce the diffused light that is the light that does not go straight without reducing the light that goes straight.

The device for reducing the diffused light may be provided between the projection optical system and the projection screen as shown in FIGS. 1 and 2, or, for example, a plurality of projection optical systems may be included in the projection optical system. When the lens is formed of the above lens, it may be arranged between the lenses. The device for reducing the diffused light is not limited to the aperture and the spot 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.

A microlens system or the like can also be used. Specifically, by disposing a microlens array and a spot array in which fine holes are arrayed on the projection optical system side of the liquid crystal display element, unnecessary diffused light can be removed. In this case, since the optical path length required for removing the diffused light can be made extremely short, there is an advantage that the entire projection type display device can be made compact. For shortening 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 suppressed smaller than the case where the projection optical system and the device for reducing the diffused light are installed independently.

These optical systems can be combined with mirrors, dichroic mirrors, prisms, dichroic prisms, lenses, etc. to synthesize and color images, and also to color images by combining them with color filters.

The ratio of the straight-ahead component and the scattered component reaching the projection screen can be controlled by the diameter of the spot, the mirror, etc. and the focal length of the lens, and can be set so that a desired display contrast and display brightness can be obtained. Good.

When a device for reducing diffused light such as an aperture is used, it is preferable that the light incident on the liquid crystal display element from the light source for projection is more parallel in order to increase the brightness of the display. It is preferable to configure a projection light source by combining a light source having a brightness and as close as possible to a point light source, a concave mirror, a condenser lens, and the like.

In the above description, the transmissive type is mainly explained, but even in the reflective type projection type display device, for example, a small mirror is arranged instead of the spot so that only necessary light is extracted. can do.

[0128]

In particular, since the present invention has the above-mentioned structure, the maximum effective voltage V applied to the liquid crystal resin composite is
Can be set to 10 V or less, and high-speed response can be obtained even in half-tone display. Therefore, using an active element or a driving IC as used in the conventional active matrix liquid crystal display element for TN, a moving image can be displayed. Easy to display.

Also, each color is well balanced, and beautiful gradation display of colors can be performed without incorporating a special correction circuit in the drive circuit.

[0130]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 A glass substrate (Corning 7059 substrate) was coated with 60% chromium.
nm was evaporated and patterned to form a gate electrode. Subsequently, a silicon oxynitride film and an amorphous silicon film were deposited by a plasma CVD device. This was annealed using a laser and then patterned to obtain polycrystalline silicon. Phosphorus-doped amorphous silicon and chromium were deposited on each of these using a plasma CVD and a vapor deposition device, and patterned so as to cover the polycrystalline silicon to form a first-layer source electrode and drain electrode.

Furthermore, after depositing ITO, patterning was performed to form pixel electrodes. Then, chromium and aluminum were continuously vapor-deposited and patterned to form a second-layer source electrode and drain electrode. At that time, the pixel electrode,
The drain electrode of the first layer and the drain electrode of the second layer are connected. After that, again, a silicon oxynitride film was deposited by a plasma CVD apparatus as a protective film to prepare an active matrix substrate.

A counter electrode substrate made of the same glass substrate on which a solid ITO electrode is formed and an active matrix substrate manufactured previously are arranged so that their electrode surfaces face each other, and a spacer having a diameter of about 11.0 μm is internally provided. After spraying, the periphery of the cell was removed except for the injection port portion, and the cell was sealed with an epoxy-based sealing material to manufacture an empty cell with an interelectrode gap d _G of 11.0 μm.

Δn is about 0.24, Δε is about 16, and K33 is about 15.
(× 10 ^-12 N), viscosity of about 37 cSt nematic liquid crystal, acrylate monomer, bifunctional urethane acrylate oligomer, and photo-curing initiator were uniformly dissolved in the cell, and the liquid crystal resin composite was cured by UV exposure. Then, an active matrix liquid crystal display device was prepared. Liquid crystal amount is 68
wt%, gap between electrodes d _G is about 11 μm, average particle size of liquid crystal is about
It was 1.6 μm.

Similarly, for red, d _R = 13.5 μm,
_{R R = 1.9μm, d B =} 9.5μm for the blue, R _B = 1.5μ
m cells were produced.

Using these elements, a projection type liquid crystal display device was prepared by combining a projection light source and a projection optical system as shown in FIG. Spot diameter φ and lens focal length f
The converging angle determined by and is δ (δ = 2tan ^-1 (φ / 2f)), and this converging angle is 6 °. Driving with a video signal and projecting an image on the screen, even in halftone display, a moving image display with good color balance without afterimage can be obtained.
The contrast ratio on the screen was about 130.

The response time (change in transmittance of 90% in black and white when RGB are operated simultaneously) is 10 msec from 8 V to 0 V, 0 V →
It is 15msec at 8V, and 0V → saturated transmittance x 0.2 (about 16
%) Was 110 msec.

Comparative Example 1 Three green liquid crystal display elements of Example 1 were prepared, and R
A projection type display device similar to that in Example 1 was configured by combining with a GB three-color light source.

The display obtained by this projection type display device is a reddish image as a whole, and this tendency is particularly remarkable in the display of halftone. When no electric field was applied to all three liquid crystal display elements, the projection screen became dark red instead of black. It is considered that this is caused by the difference in the threshold voltage characteristics of the liquid crystal depending on RGB. Examining the applied voltage-transmittance characteristics for each RGB, R is the most transmitted at the same applied voltage in the halftone region. The rate was high and B was the lowest.

Comparative Example 2 In place of the liquid crystal resin composite of Example 1, ordinary nematic liquid crystal was injected to manufacture a projection type active matrix liquid crystal display device as a TN type liquid crystal display device.

This liquid crystal display device was combined with the projection light source and the projection optical system of Example 1 to form a projection type liquid crystal display device, and when driven in the same manner as in Example 1, the display brightness on the projection screen was As dark as about 1/3 of the case of Example 1,
A contrast ratio of about 100 was obtained.

The response time is 5 V → 0 V, 25 msec, 0 V →
It is 30msec at 5V, and 0V → saturated transmittance x 0.2 (about 6
%) Was 160 msec.

Examples 2 to 3 and Comparative Example 3 In substantially the same manner as in Example 1, an active matrix liquid crystal display device was manufactured by changing the average particle diameter R of the liquid crystal and the gap d between the electrodes. The liquid crystal display device has a transmittance T _8V when a voltage of 8V is applied, a contrast ratio CR on the screen when projected using a projection optical system, and a response time at 0V → saturated transmittance × 0.2 (about 16%). τ was measured.

The average particle diameter R _X of the liquid crystal of the liquid crystal display element for each color and the inter-electrode gap d _X were set as follows. In Example 2, for red, R _R = 1.6 μm, d _R = 11.5 μm, and for green, R _G = 1.
6 μm, d _G = 10.0 μm, for blue R _B = 1.6 μm, d _B = 9.5
μm. In Example 3 for red, R _R = 1.9 μm and d _R = 13.5.
μm, R _G = 1.6 μm for green, d _G = 11.0 μm, R _B = for blue
1.6μm, was d _B = 10.0μm. R _R = for comparative example 3 for red
3.0 μm, d _R = 15.5 μm, for green R _G = 2.5 μm, d _G = 1
3.0μm, is for blue was the _{R B = 2.3μm, d B =} 11.0μm.

The results are shown in Table 1. The color balance of each of Examples 2 and 3 and Comparative Example 3 was good.

[0146]

[Table 1]

Example 4 A liquid crystal display device was prepared in substantially the same manner as in Example 1. However, the average particle diameter of the liquid crystal used for the liquid crystal display element of each color and the gap between the electrodes were constant (R = 1.7 µm, d = 11.0 µm), and the physical properties of the liquid crystal were changed as follows.

For red, the liquid crystal Δn = about 0.29, Δε = about 16,
K33 = about 16 (× 10 ^-12 N), viscosity = about 52 cSt. The liquid crystal for green is Δn = about 0.24, Δε = about 16, K33 = about 15 (× 10
^-12 N), viscosity = about 37 cSt. For blue, the liquid crystal Δn = about 0.22,
Δε = about 15, K33 = about 16 (x10 ^-12 N), viscosity = about 34 cSt
.

Using these elements, a projection type liquid crystal display device was prepared by combining a projection light source and a projection optical system as shown in FIG. The collection angle was 5 °. Drive voltage in effective value
When the image was projected on a screen by driving it with 7 V and a video signal, a moving image display with good color balance without afterimage was obtained even in halftone display, and the contrast ratio on the screen was about 130.

The response time is 7 V → 0 V, 20 msec, 0 V →
It is 20msec at 7V, 0V → saturated transmittance x 0.2 (about 16
%) Was 100 msec.

Example 5 A liquid crystal display device was prepared in substantially the same manner as in Example 1. However, the physical properties of the liquid crystal used for the liquid crystal display element of each color, the average particle diameter, and the gap between the electrodes were changed as follows.

For red, the liquid crystal has Δn = about 0.29, Δε = about 16,
K33 = approx. 16 (× 10 ^-12 N), viscosity = approx. 52 cSt, R _R = 1.5 μ
m, d _R = 11.0 μm. For green, the liquid crystal Δn = about 0.24, Δε =
About 16, K33 = about 15 (× 10 ^-12 N), viscosity = about 37 cSt, R _G =
1.5 μm, d _G = 11.0 μm. For blue, the liquid crystal Δn = about 0.24,
Δε = about 16, K33 = about 15 (× 10 ^-12 N), viscosity = about 37 cSt
_{, R B = 1.5μm, d B} = 10.0μm.

Using these elements, a projection type liquid crystal display device was prepared by combining a projection light source and a projection optical system as shown in FIG. The collection angle was 5 °. Drive voltage in effective value
When the image was projected on a screen by driving it at 8 V with a video signal, a moving image display with good color balance without afterimage was obtained even in halftone display, and the contrast ratio on the screen was about 120.

The response time is 8 m → 0 V, 20 msec, 0 V →
20msec at 8V, 0V → saturated transmittance x 0.2 (about 16
%) Was 100 msec.

Example 6 The counter electrode was made of aluminum to form a reflection type element, and the gap between the electrodes was d _R = 6.0 μm, d _G = 5.0 μ.
m, d _B = 4.5 μm, average particle size R _R = 1.9 μm, R _G =
An active matrix liquid crystal display device was prepared in substantially the same manner as in Example 1 except that 1.6 μm and R _B = 1.5 μm. However, the reflectance of the surface of the liquid crystal display device was set to about 0.3%.

When this was driven with an effective value of 5 V and driven by a video signal and an image was projected on the screen, a moving image display with good color balance without afterimage was obtained even in halftone display. The contrast ratio at was about 100.

The response time is 5 m → 0 V, 8 msec, 0 V →
It is 12msec at 5V, and 0V → saturated transmittance x 0.2 (about 16
%) Was 80 msec.

Comparative Example 4 Δn is about 0.24, Δε is about 16, K33 is about 18 (× 10 ⁻¹² N),
Using an nematic liquid crystal having a viscosity of about 54 cSt, an active matrix liquid crystal display device was prepared in substantially the same manner as in Example 1.

Average particle diameter R of liquid crystal of each color and gap between substrates
d is R _R = 2.0 μm for red, d _R = 13.5 μm, R _G = for green
1.7 μm, d _G = 11.0 μm, for blue R _B = 1.5 μm, d _B = 1
It was set to 0.0 μm.

When this was driven with a drive voltage of 8 V as an effective value and driven by a video signal and an image was projected on a screen, an afterimage was seen particularly in a dark halftone display. The response time is 40 msec from 8 V to 0 V, 35 msec from 0 V to 8 V, and 400 mse at 0 V to saturated transmittance x 0.2 (about 16%).
It was c.

Example 7 An empty cell having color filters of RGB three colors formed on the inner surface was formed. At this time, the gap of the red color filter portion was d _R = 11.0 μm, the gap of the green color filter portion was d _G = 10.0 μm, and the gap of the blue color filter portion was d _B = 9.5 μm.

A solution in which nematic liquid crystal was uniformly dissolved in an acrylate monomer, a urethane acrylate oligomer, and a photo-curing initiator was injected into this empty cell, and the liquid crystal resin composite was cured by exposure to ultraviolet rays to prepare an active matrix liquid crystal display device. did. The Δn of the liquid crystal used is about
0.24, Δε is about 16, K33 is about 15 (× 10 ^-12 N), viscosity is about
It was 37 cSt. The average particle size of the liquid crystal was 1.5 μm.

When a black absorber was placed on the background and this liquid crystal display device was driven by a video signal, a fine color display with gradation without image sticking or image sticking was obtained. The contrast ratio of the liquid crystal display device was about 100. When this liquid crystal display element, a light source for projection, and a projection optical system are combined to form a projection type display device, and an image is projected on the screen,
A delicate color display with no afterimage or burn-in was obtained, and the contrast ratio on the screen was about 70.

Example 8 Δn is about 0.24, Δε is about 16, K33 is about 15 (× 10 ⁻¹² N),
Using an nematic liquid crystal having a viscosity of about 37 cSt, an active matrix liquid crystal display device was prepared in substantially the same manner as in Example 1. The average particle size R of the liquid crystal of each color and the gap d between the substrates are
For red, R _R = 1.9 μm, d _R = 12.0 μm, and for green and blue, R _G = R _B = 1.6 μm and d _G = d _B = 10.0 μm.

When this was driven with a video signal at a converging angle of about 6 ° and an image was projected on the screen, an image slightly lacking in the blue component was obtained. Therefore, the drive voltage for red and green is 7V in effective value, and the drive voltage for blue is 8V in effective value.
As a result, when driven by a video signal and an image was projected on the screen, a moving image display with good color balance without an afterimage was obtained even in halftone display. The contrast ratio on the screen was about 100.

The response time is 8 m → 0 V, 10 msec, 0 V →
It was 15 msec at 7 V (8 V for blue) and 110 msec at 0 V → saturated transmittance × 0.2 (about 16%).

[0167]

In the active matrix liquid crystal display device of the present invention, as the liquid crystal material sandwiched between the active matrix substrate and the counter electrode substrate, a liquid crystal resin composite capable of electrically controlling the scattering state and the transmitting state. Since a liquid crystal display element sandwiching the above is used, a polarizing plate is not necessary, the transmittance of light at the time of transmission can be significantly improved, and a bright projected image can be obtained.

The liquid crystal display device of the present invention has a high scattering property when no voltage is applied, and a high transmissivity when a voltage is applied by an active device.
Even in the case where the driving IC for the N-type liquid crystal display element is used for driving, a display having a high contrast ratio and high luminance can be realized.

Further, in the present invention, since the characteristics of the liquid crystal display element are optimized for each color light source, a display having a good color balance can be obtained even in a halftone. Furthermore, it is difficult for an afterimage to occur even when gradation driving is performed.

Therefore, the liquid crystal display device of the present invention is effective for projection type display, and bright, color-balanced, and good-contrast projection type display can be obtained. Also, the light source can be downsized.

Further, since it is not necessary to use a polarizing plate, there is an advantage that optical characteristics have little wavelength dependence and color correction of a light source is almost unnecessary. Further, 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 static electricity associated therewith can be avoided, the manufacturing yield of the liquid crystal display element can be greatly improved.

Further, since this liquid crystal resin composite is in the form of a film after being cured, problems such as short circuit 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 resin composite has a specific resistance equivalent to that in the conventional TN mode, and it is not necessary to provide a large storage capacity for each pixel electrode as in the conventional DS mode, and the active element The design is easy, the ratio of the effective pixel electrode area can be easily increased, and the power consumption of the liquid crystal display element can be kept low.

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

Further, the liquid crystal display element using this liquid crystal resin composite has a feature that the response time is short, and it is easy to display a moving image. Further, since the electro-optical characteristic (voltage-transmittance) of this liquid crystal display element is a comparatively gentle characteristic as compared with the TN mode liquid crystal display element,
It is also easy to apply to gradation display.

Further, in the liquid crystal display element of the present invention, by making the refractive index of the resin matrix substantially match the ordinary refractive index (n _o ) of the liquid crystal used, light is scattered in the portion to which no voltage is applied. Therefore, even if the portion other than the pixel is not shielded by the light shielding film, light does not leak at the time of projection and it is not necessary to shield the gap between the adjacent pixels.

Therefore, in particular, by using an active element made of polycrystalline silicon as the active element, it is possible to use a high-luminance projection light source only by providing no light-shielding film or a simple light-shielding film in the active element portion. Therefore, a high-brightness projection type liquid crystal display device can be easily obtained. Further, in this case, the light-shielding film may not be provided at all, or only a simple light-shielding film may be required, and the production process can be further simplified.

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.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic configuration of a projection type active matrix liquid crystal display device of the present invention.

FIG. 2 is a schematic diagram showing a basic configuration of a projection type active matrix liquid crystal display device of the present invention.

FIG. 3 is a sectional view showing a basic configuration of an active matrix liquid crystal display device of the present invention.

[Explanation of symbols]

Light source: 1, 11 Concave mirror: 2, 12 Active matrix liquid crystal display device: 6A, 6B, 6C, 16
A, 16B, 16C Projection lens: 8, 18A, 18B, 18C Projection screen: 10, 20 Liquid crystal display element: 21 Substrate: 22, 25 Pixel electrode: 23 Active element: 24 Counter electrode: 26 Liquid crystal resin composite: 27

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Niiyama             1150 Hazawa-machi, Kanagawa-ku, Yokohama-shi, Kanagawa             Asahi Glass Co., Ltd. Central Research Laboratory (72) Inventor Yutaka Kumai             1150 Hazawa-machi, Kanagawa-ku, Yokohama-shi, Kanagawa             Asahi Glass Co., Ltd. Central Research Laboratory

Claims (8)

[Claims] 1. A projection active system having a plurality of color light sources, a plurality of active matrix liquid crystal display elements on which light from the respective color light sources is incident, and a projection optical system for synthetically projecting the light emitted from the active matrix liquid crystal display elements. In a matrix liquid crystal display device, a nematic liquid crystal having a positive dielectric anisotropy is a resin between an active matrix substrate in which an active matrix liquid crystal display element has an active element provided for each pixel electrode and a counter electrode substrate having a counter electrode. By sandwiching a liquid crystal resin composite, which is dispersed and held in the matrix, and the refractive index of the resin matrix is almost the same as the refractive index of the liquid crystal to be used when the voltage is applied or not applied. Which is an active matrix liquid crystal display element, and has an average particle diameter R _x ( μm), interelectrode gap d _x (μm), liquid crystal relative dielectric anisotropy Δε _x , elastic constant K33 _x (10 ⁻¹² N), viscosity η _x (cSt), refractive index anisotropy Δn _x , each color Dominant wavelength of λ _x (μ
m) and Δn _x ² · Δε _x / (K33 _x · η _x )> 0.0011 (1) 4 (K33 _x / η _x ) ^0.5 > R _x ＞ (K33 _x / Δε _x ) ^0.5 (2) Is satisfied, and i ≠ j between at least one set of active matrix liquid crystal display elements, Δn _i · R _i / λ _i ≈Δn _j · R _j / λ _j (3) and d _i / R _i ≈d _j / R _j (4) or Δn _i・ d _i ² / λ _i ≈Δn _j・ d _j ² / λ _j (5) Matrix liquid crystal display device. 2. The projection type active matrix liquid crystal display device according to claim 1, wherein the relationship Δn _x ² · Δε _x / (K33 _x · η _x )> 0.0014 (1A) is satisfied. -Type active matrix liquid crystal display device. 3. The projection type active matrix liquid crystal display device according to claim 1, wherein the color light source is a color light source of RGB three colors, and x satisfies the expressions (1) and (2) for all three RGB colors, and Δn _R・ R _R / λ _R ≈Δn _G・ R _G / λ _G ≈Δn _B・ R _B / λ _B (3A) and d _R / R _R ≈d _G / R _G ≈d _B / R _B (4A) Characterized by satisfying the relation or satisfying the relation of Δn _R・ d _R ² / λ _R ≈ Δn _G・ d _G ² / λ _G ≈ Δn _B・ d _B ² / λ _B (5A) Projection type active matrix liquid crystal display device. 4. The projection type active matrix liquid crystal display device according to claim 1, wherein the refractive index anisotropy Δ of the liquid crystal used in the active matrix liquid crystal display element.
A projection type active matrix liquid crystal display device, characterized in that when n _x is λ _i > λ _j , the relationship of Δn _j ≦ Δn _i is satisfied. 5. The projection type active matrix liquid crystal display device according to claim 1, wherein the refractive index anisotropy Δn _{x of} the liquid crystal used for each color and the average particle diameter R _{x of the} liquid crystal held in the resin matrix. All of the above satisfy the relationship of 0.2 <R _x · Δn _x <0.7 (6), a projection type active matrix liquid crystal display device. 6. The projection type active matrix liquid crystal display device according to claim 1, wherein liquid crystal of each color has an average particle diameter R _x (μm), a gap d _x between electrodes, and a liquid crystal resin composite. It is characterized in that the maximum effective applied voltage V _x (V) satisfies the relationship of 3R _x <d _x <9R _x (7) 0.6R _x · V _x <d _x <1.2R _x · V _x (8). Projection type active matrix liquid crystal display device. 7. A nematic liquid crystal having positive dielectric anisotropy between an active matrix substrate having color filters of RGB three colors, each pixel electrode having an active element, and a counter electrode substrate having a counter electrode. Is dispersed and held in the resin matrix, and the liquid crystal resin composite is sandwiched so that the refractive index of the resin matrix is almost the same as the refractive index of the liquid crystal used when voltage is applied or not applied. In an active matrix liquid crystal display device formed by
Average particle diameter R (μm) of liquid crystal of each color dispersed and held in resin matrix, interelectrode gap d _x (μm), relative dielectric anisotropy Δε of liquid crystal, elastic constant K33 (10 ^-12 N), viscosity η (cSt), refractive index anisotropy Δn, and dominant wavelength λ _x (μm) of each color are Δn ² · Δε / (K33 · η)> 0.0011 (1B) 4 (K33 / η) ^0.5 >R> ( K33 / Δε) ^0.5 (2B) 0.2 <R · Δn <0.7 (6B) 3R <d _G <9R (7B), and at least 2 of the 3 RGB colors
An active matrix liquid crystal display device characterized by satisfying a relationship of d _i ² / λ _i ≈d _j ² / λ _j (5B), where i ≠ j in relation to color. 8. A projection type active matrix liquid crystal display device comprising the active matrix liquid crystal display element according to claim 7 in combination with a projection light source and a projection optical system.