JPH0580311A - Liquid crystal panel and production thereof and liquid crystal projection type television - Google Patents

Abstract

PURPOSE:To obtain an extremely high contrast and to provide a good image display. CONSTITUTION:Projecting patterns 15 are formed of a dielectric material on a counter electrode. The liquid crystal in parts A existing between the projecting patterns 15 orients if a signal is impressed to the counter electrode 16 at the time of polymerizing the high-polymer dispersed liquid crystal 17 with UV rays to polymerize the liquid crystal. Electric fields are, however, hardly impressed to the liquid crystal in the parts B and the resin component of the liquid crystal 17 is polymerized in the non-oriented state. The refractive index n1 of the parts A of the liquid crystal 17 and the refractive index n2 of the parts B attain a relation n1<n2 and the liquid crystal eventually has the function of a macro-lens. The liquid crystal of the parts B orient, and, therefore, the refractive indices attain n1=n2 and the lens function disappears, when the voltage is impressed between the counter electrode 16 and picture element electrodes 13. Then, a refractive index difference arises between the parts A and B and the incident light is refracted and scattered when the high-polymer dispersed liquid crystal 17 is in a scattering mode. Then, the incident light advancing rectilinearly in the panel is drastically decreased. The refractive index difference annihilates and the incident light passes as it is when the high-polymer dispersed liquid crystal 17 is in a transmission mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projection television for mainly projecting an image displayed on a small liquid crystal panel on a screen, a liquid crystal panel mainly used for the liquid crystal projection television, and a manufacturing method thereof. Is.

[0002]

2. Description of the Related Art Since a liquid crystal panel has many features such as a light weight and a thin shape, research and development have been actively conducted. However, there are many problems such as difficulty in increasing the screen size. Therefore, in recent years, a liquid crystal projection television, which enlarges and projects a display image on a small liquid crystal panel with a projection lens or the like to obtain a display image on a large screen, is suddenly attracting attention. At present, liquid crystal projection televisions that have been commercialized use twisted nematic (hereinafter referred to as TN) liquid crystal panels that utilize the optical rotation characteristics of liquid crystals.

FIG. 9 is an equivalent circuit diagram of a liquid crystal panel. G _{1 to} G _m are gate signal lines, one end of which is connected to the gate drive IC 91. S _{1 to} S _n are source signal lines, one end of which is connected to the source drive IC 92. Each pixel has a thin film transistor (hereinafter referred to as a TFT) 93 for applying a signal to a pixel electrode, and an additional capacitor 94 for holding a signal is formed. Reference numeral 95 denotes a liquid crystal sandwiched between the pixel electrode and the counter electrode, which can be regarded as a capacitor in terms of an electric circuit.

FIG. 10 is a sectional view of a conventional liquid crystal panel. As an example of the liquid crystal projection television and the liquid crystal panel used in the television, there is "Flat panel display '91, pages 194 to 205, published by Nikkei BP." The array substrate 12 and the counter electrode substrate 101 are 4 to 6 μm
And the TN liquid crystal 103 is injected between the substrates. Sealing resin (not shown) around the display area
It is sealed with. Although not shown, the counter electrode 1
An alignment film is formed on 6 and on the pixel electrode 13.

A conventional method for manufacturing a liquid crystal panel will be described below. First, the array substrate 12 and the counter electrode substrate 11
An alignment film is applied to the film and is subjected to alignment treatment by rubbing. After that, the sealing resin is applied to the peripheral portion of the array substrate 12 while leaving the injection port of the TN liquid crystal 103. In addition, beads for obtaining a uniform liquid crystal film thickness are scattered on the counter electrode substrate 101. Next, the counter electrode substrate 101 and the array substrate 12 are bonded together. After that, the sealing resin is cured by irradiation with ultraviolet rays or heating. Next, the bonded substrates are placed in a vacuum chamber, the gap between the array substrate 12 and the counter electrode substrate 101 is evacuated, and the liquid crystal injection port is immersed in the liquid crystal. After that, when the vacuum in the vacuum chamber is broken, the liquid crystal is injected into the gap through the injection port. Finally, the injection port is sealed and completed.

A conventional liquid crystal projection television will be described below with reference to the drawings. FIG. 11 is a configuration diagram of a conventional liquid crystal projection television. In FIG. 11, 11
1 is a condensing optical system, 112 is a UVIR cut mirror for transmitting infrared rays and ultraviolet rays, 113a is a blue light reflection dichroic mirror (hereinafter referred to as BDM), 113b is a green light reflection dichroic mirror (hereinafter referred to as GDM), and 113c. Is a red light reflecting dichroic mirror (hereinafter referred to as RDM), 114a, 114b, 114c,
116a, 116b, 116c are polarizing plates, and 115a, 1
15b and 115c are transmissive TN liquid crystal panels 117
Reference numerals a, 117b and 117c are projection lens systems. In addition,
Structures unnecessary for the description are omitted from the drawings.

The operation of the conventional liquid crystal projection television will be described below with reference to FIG. First, the white light emitted from the condensing optical system 111 is reflected by the BDM 113a as blue light (hereinafter referred to as B light), and the B light is incident on the polarizing plate 114a. The light transmitted through the BDM 113a is reflected by the GDM 113b as green light (hereinafter, referred to as G light), and is reflected by the polarizing plate 114b.
The red light (hereinafter, referred to as R light) is reflected by c and is incident on the polarizing plate 114c. The polarizing plate transmits only one of the longitudinal wave component and the transverse wave component of each color light, aligns the polarization directions of the light, and irradiates each liquid crystal display device. At this time, 50
% Or more of the light is absorbed by the polarizing plate, and the brightness of the transmitted light is half that of the incident light even at the maximum.

Each liquid crystal panel modulates the transmitted light according to a video signal. The modulated light passes through the polarizing plates 116a, 116b and 116c depending on the degree of modulation, and is enlarged and projected on a screen (not shown) by the projection lens systems 117a, 117b and 117c.

[0009]

As is clear from the above description, in a liquid crystal panel using TN liquid crystal, it is necessary to make linearly polarized light incident. Therefore, it is necessary to dispose polarizing plates before and after the liquid crystal panel. Theoretically, this polarizing plate absorbs more than half of the light. Therefore, when the TN liquid crystal panel is used in a liquid crystal projection television, there is a problem that only a low brightness screen can be obtained.

There is also a problem that the polarizing plate is heated by incident light and becomes high in temperature, and the characteristics are deteriorated in a short time. Further, there is also a problem that heat rays emitted from the heated polarizing plate and the like are conducted to the liquid crystal panel, which brings the liquid crystal panel to a high temperature state and deteriorates it. The present invention has been made in view of the above problems.

[0011]

A liquid crystal panel of the present invention uses polymer dispersed liquid crystal as a liquid crystal, and a projection pattern made of a dielectric material is formed on a counter electrode at a position facing a signal line formed on an array substrate. Is forming. Further, the refractive index of the polymer-dispersed liquid crystal is changed according to the formation period of the protrusion pattern.

The liquid crystal panel manufacturing method of the present invention is to inject a resin containing liquid crystal between the array substrate and the counter electrode substrate, apply a voltage to the counter electrode, and cure the resin. Since the projection pattern causes a periodical strength distribution in the electric field applied to the liquid crystal, the alignment state of the liquid crystal molecules also has a periodic distribution. By curing the resin in this state, the periodic intensity distribution is fixed and a refractive index distribution is generated in the liquid crystal layer.

Further, the liquid crystal projection type television of the present invention uses the liquid crystal panel of the present invention as a light valve. By applying a voltage to the pixel electrode of the liquid crystal panel to eliminate the periodical refractive index distribution of the liquid crystal layer, the incident light on the panel goes straight. When no voltage is applied, the refractive index distribution acts like a lens, and the light refraction effect of the lens and the scattering effect of polymer-dispersed liquid crystal efficiently change the direction of light emitted from the liquid crystal panel for projection. Avoid entering the lens.

[0014]

First, the polymer dispersed liquid crystal will be briefly described. Polymer dispersed liquid crystals are roughly classified into two types depending on the dispersion state of liquid crystals and polymers. One is a type in which liquid crystals in the form of water droplets are dispersed in a polymer. The liquid crystal exists in the polymer in a discontinuous state. Hereinafter, such a liquid crystal will be referred to as a PDLC, and a liquid crystal panel using the liquid crystal will be referred to as a PD liquid crystal panel. The other is a type that has a structure in which a polymer network is stretched around the liquid crystal layer. It looks like a sponge containing liquid crystal. The liquid crystal does not form a water drop but continuously exists. Hereinafter, such a liquid crystal will be referred to as a PNLC, and a liquid crystal panel using the liquid crystal will be referred to as a PN liquid crystal panel. In order to display an image with the above-mentioned two types of liquid crystal panels, light scattering and transmission are controlled.

PDLC utilizes the property that the refractive index is different in the direction in which the liquid crystal is aligned. When no voltage is applied, each water droplet liquid crystal is oriented in an irregular direction. In this state, a difference in refractive index occurs between the polymer and the liquid crystal, and incident light is scattered. When a voltage is applied here, the alignment directions of the liquid crystal are aligned. If the refractive index when the liquid crystal is oriented in a certain direction is matched with the refractive index of the polymer in advance, incident light is transmitted without being scattered.

On the other hand, PNLC uses the irregularity itself of the alignment of liquid crystal molecules. The incident light is scattered in the irregular alignment state, that is, in the state where no voltage is applied.
On the other hand, light is transmitted when a voltage is applied and the array state is made regular. The above description of the movement of the liquid crystal of PDLC and PNLC is merely a model idea. Although the present invention is not limited to one of the PD liquid crystal panel and the PN liquid crystal panel, it is not limited to the PD liquid crystal panel for ease of explanation.
A liquid crystal panel will be described as an example. Further, PDLC and PNLC are collectively referred to as polymer dispersed liquid crystal, and PD liquid crystal panel and PN liquid crystal panel are collectively referred to as polymer dispersed liquid crystal panel. A liquid containing a liquid crystal to be injected into a polymer dispersed liquid crystal panel is generically called a liquid crystal solution, and a state in which a resin component in the liquid crystal solution is polymerized and cured is called a polymer.

Operation of polymer dispersed liquid crystal (FIG. 8)
A brief description will be given using (a) and (b). (Fig. 8 (a)
(B) is an explanatory view of the operation of the polymer dispersed liquid crystal panel. In FIGS. 8A and 8B, 81 is an array substrate, 82 is a pixel electrode, 83 is a counter electrode, 84 is a liquid crystal droplet, 85 is a polymer, and 86 is a counter substrate. A TFT or the like is connected to the pixel electrode 82, and a voltage is applied to the pixel electrode by turning on / off the TFT. The voltage changes the liquid crystal alignment direction on the pixel electrode and modulates the incident light. As shown in FIG. 8A, in the state in which no voltage is applied, each water droplet liquid crystal 84 is oriented in an irregular direction. In this state, a difference in refractive index occurs between the polymer 85 and the liquid crystal 84, and incident light is scattered. Here, when a voltage is applied to the pixel electrode as shown in (FIG. 8B), the directions of the liquid crystals are aligned. If the refractive index when the liquid crystal is aligned in a certain direction is matched with the refractive index of the polymer in advance, incident light is emitted from the array substrate 81 without being scattered.

In order to construct a high quality display panel using polymer dispersed liquid crystal, the amount of light transmitted in the scattered state is
It is necessary to increase the ratio of the amount of transmitted light in the transmitted state (hereinafter referred to as contrast). If the contrast is low, the gradation display characteristics deteriorate. A liquid crystal projection television needs a contrast of 100 or more. The maximum transmittance of the polymer-dispersed liquid crystal panel is regulated by the ITO film or the like of the counter electrode, but it is as high as 80 to 85%. However, the light transmission amount at the time of scattering is also large. In order to increase the contrast, it is necessary to reduce the amount of transmission in the scattered state (hereinafter referred to as scattering transmittance). In order to reduce the amount of transmission in the scattering state, it is necessary to increase the film thickness of the liquid crystal layer, but if the thickness is increased, the applied voltage for setting the transmission state becomes high and the liquid crystal cannot be driven. From the above, although the brightness can be increased by using the polymer-dispersed liquid crystal, the contrast cannot be increased, and it has been difficult to construct a good liquid crystal panel and a liquid crystal projection television.

In the liquid crystal panel of the present invention, a protrusion pattern made of a dielectric material is formed on the counter electrode. The voltage applied between the counter electrode and the pixel electrode is applied as it is to the liquid crystal layer at the portion where the protrusion pattern is absent. Since the protrusion pattern is formed of a dielectric material at the portion where the protrusion pattern is formed, the voltage applied between the counter electrode and the pixel electrode is divided between the protrusion pattern and the liquid crystal layer. Therefore, the voltage applied to the liquid crystal layer becomes small. On the other hand, when a voltage is applied to the liquid crystal solution, the liquid crystal is oriented in one direction by the voltage. The refractive index of the liquid crystal is the ordinary refractive index n _o becomes dominant in the liquid crystal alignment state. A refractive index of the liquid crystal of the extraordinary refractive index n _e and n _o are mixed in a scattering state. When a voltage is applied to the counter electrode in a state of being injected between the liquid crystal solution and the substrate, a strong and weak electric field distribution is generated in the liquid crystal solution at the cycle of the protrusion pattern. Therefore, since the liquid crystal in the liquid crystal solution also has a periodic alignment distribution, a refractive index distribution is generated. When the protrusion pattern is formed in a matrix, a refractive index distribution is formed from the center of the matrix to the peripheral direction. If the liquid crystal solution is polymerized in the above state, the refractive index distribution is fixed. When no voltage is applied between the counter electrode and the pixel electrode, the refractive index distribution has a lens-like function and refracts light incident on the liquid crystal layer. On the other hand, a voltage is applied between the counter electrodes and the pixel electrodes, if completely orient the liquid crystal, ordinary refractive index n _o is dominant throughout the liquid crystal layer. At this time, if the refractive index n _{p of the} polymer and the ordinary refractive index n _{o of the} liquid crystal are set to be the same, the light incident on the liquid crystal layer goes straight without being refracted.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal panel of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a liquid crystal panel of the present invention. It should be noted that parts unnecessary for description are omitted, and there are parts exaggerated for ease of drawing. The above also applies to the following drawings. In FIG. 2, 11 is a counter electrode substrate on which a counter electrode 16 made of ITO or the like is formed, and 12 is an array substrate on which signal lines such as source signal lines 14 and pixel electrodes 13 and TFTs (not shown) are formed. , 17 are polymer dispersed liquid crystals. Reference numeral 15 is a convex pattern made of a dielectric material (hereinafter, referred to as a projection pattern), which corresponds to TaOx, SiO ₂ , SiNx or the like as an example of a forming material.
A plan view of the counter electrode substrate in FIG. 1 is shown in FIG.
Further, a cross-sectional view taken along the line AA ′ of (FIG. 2) is shown in (FIG. 3). As shown in (FIG. 1) and (FIG. 3), the protrusion pattern is formed in a matrix on the counter electrode 16 in the upper layer of the source signal line 14 and the gate signal line (not shown). The pattern has a smooth arc shape, and its maximum height is preferably 0.2 μm to 3 μm. Further, the width is positioned so as to overlap the pixel electrode 13. The degree of overlap depends on the thickness of the liquid crystal layer, the refractive index, and the like, but it is preferable that the overlap overlaps the area of ¼ or more of the pixel electrode.

The liquid crystal of the polymer dispersed liquid crystal layer 17 is preferably a nematic liquid crystal, a smectic liquid crystal, or a cholesteric liquid crystal, and may be a single or a mixture of two or more kinds of liquid crystal compounds or a mixture containing substances other than the liquid crystal compounds. ..
Of the above-mentioned liquid crystal materials, the cyanbiphenyl nematic liquid crystal is most preferable. The resin material is preferably a transparent polymer, and may be a thermoplastic resin, a thermosetting resin, or a photocurable resin, but it is an ultraviolet curable type from the viewpoint of ease of manufacturing process, separation from the liquid crystal layer, etc. It is preferable to use the above resin. As a specific example, an ultraviolet-curable acrylic resin is exemplified, and a resin containing an acrylic monomer or an acrylic oligomer that is polymerized and cured by ultraviolet irradiation is particularly preferable. By irradiating with ultraviolet rays, these cause a polymerization reaction only in the resin to become a polymer, and only the liquid crystal undergoes phase separation. At this time, when the amount of liquid crystal is smaller than that of the resin component, independent particle-shaped liquid crystal droplets are formed. On the other hand, when the amount of liquid crystal is large, the resin matrix is particulate in the liquid crystal material. , Or exist in the form of a network and the liquid crystals are formed so as to form a continuous layer.

Unless the particle size of the water-drop liquid crystal or the pore size of the polymer network is uniform to some extent and the size is in the range of 0.1 μm to several μm, the incident light scattering performance is poor and the contrast cannot be improved. The particle size of the water-drop liquid crystal or the pore size of the polymer network is preferably in the range of 0.5 μm to 1.5 μm. For this reason, it is necessary to use a material that can be cured in a short time, such as an ultraviolet curable resin. The orientation ratio of the liquid crystal material and the resin material is 9: 1 to 1: 9, and the range of 2: 1 to 1: 2 is preferable.

The thickness of the liquid crystal layer 17 is 5 μm to 20 μm.
m, and the scattering characteristic is in the range of 8 μm to 15 μm.
And the range of applied voltage to drive the liquid crystal is optimal.
is there. The film thickness is the maximum transmission of the liquid crystal at the applied voltage of 6-8V.
The rate may be set to about 90%. Liquid crystal layer 1
7 has a periodic refractive index distribution. Mode that state
(Fig. 4). For ease of explanation
N is the refractive index of the polymer _p, The ordinary refractive index of liquid crystal is n_o， Abnormal
Optical refractive index n_eAnd n_o<N_e, N_p= N_oTo do. (Figure
The refractive index of the portion A of 4) is the ordinary refractive index n of the liquid crystal._oIs supported
It's all about sharing. In addition, its intensity is at the center of the pixel electrode.
N the macro_oGet closer to. This refractive index
n₁And The liquid crystal in part B is in an irregular alignment state,
Almost the refractive index is (2n_o+ N_e) / 3.
This refractive index is n₂And Therefore, n₁<N₂Becomes
Therefore, as a model, a difference in refraction occurs at the boundary between A and B, and
It has a concave lens function. Because
Then, it is refracted at an angle of θ which is incident on the liquid crystal layer. In addition,
At the folding rate B, as shown in FIG.
The light is scattered.

As described above, when no voltage is applied between the counter electrode 16 and the pixel electrode B, incident light on the liquid crystal panel is refracted and scattered by the concave lens and the liquid crystal in the form of water droplets.
The scattering transmittance is very small. On the other hand, the liquid crystal portion of the refractive index B and a voltage is applied between the counter electrode 16 and the pixel electrode 13 is also oriented, ordinary refractive index n _o is dominant. Therefore, the boundary between the refractive indices A and B disappears and the function of the concave lens disappears. Further, since n _p = n _o , there is no difference in refractive index between the water droplet liquid crystal and the polymer. From the above, the liquid crystal layer 17
Has a refractive index of n _{p as a} whole, the incident light goes straight without being refracted or scattered. Therefore, the contrast of the liquid crystal panel of the present invention can be made very high.

The method of manufacturing the liquid crystal panel of the present invention will be described below. First, a dielectric film is applied or vapor-deposited on the counter electrode 16. Next, to form the protrusion pattern,
A mask is formed on the dielectric film. A protrusion pattern is formed using the mask. As a forming method, there is a method using chemical etching, O ₂ asher or RIE. Next, after removing the mask, beads for obtaining a predetermined liquid crystal film thickness are scattered on the counter electrode substrate 11 on which the protrusion pattern is formed as described above. on the other hand,
A sealing resin (not shown) is applied onto the array substrate 12.
Then, the counter electrode substrate 11 and the array substrate 12 are aligned and bonded. At that time, the projection pattern 15 is positioned so as to be located above the signal line of the array substrate. After positioning and bonding, the sealing resin is cured.
Liquid crystal injection methods include a vacuum injection method and a pressure injection method. In the vacuum injection method, the bonded substrates are placed in a vacuum chamber, the array substrate 12 and the counter electrode substrate 11 are evacuated, and the liquid crystal injection port is immersed in the liquid crystal solution. When the vacuum state of the vacuum chamber is broken, the liquid crystal solution is injected between both substrates. On the other hand, in the pressure injection method, the liquid crystal solution is injected by pressure from an injection port of 0.8 to 1.2 mm formed and formed in the peripheral portion of the counter electrode substrate 11.

Next, a signal is applied to the counter electrode 16 and the liquid crystal solution is heated or irradiated with ultraviolet rays to polymerize the resin. The signal may be a rectangular wave, a sine wave, a triangular wave, or the like, but its effective value is adjusted in consideration of the film thickness of the liquid crystal layer, the pitch of the projection pattern, and the like. In addition, a predetermined voltage is applied to the common electrode that covers one end of the additional capacitor 94 to fix the potential. When a signal is applied as described above, an electric field is applied to the liquid crystal layer 17 and the liquid crystal is aligned. Since the projection pattern is now formed in an arc shape, the electric field applied to the liquid crystal layer 17 can also have a gentle intensity distribution. The intensity of the alignment state of the liquid crystal changes according to the distribution. The alignment state is fixed by polymerizing the resin in the above state. As described above, the refractive index distribution can be formed in the liquid crystal layer. As described above, the liquid crystal panel of the present invention is completed.

Although the projection pattern 15 is formed in an arc shape, the invention is not limited to this. For example, as shown by 51 in (FIG. 5), a planar convex projection pattern may be used. Also in this case, depending on the position where the source signal line and the common electrode are formed, it is possible to cause the liquid crystal layer 17 to have a different refractive index distribution. Therefore, a refractive index distribution can be formed in the liquid crystal layer.

The liquid crystal projection television of the present invention will be described below with reference to the drawings. FIG. 6 is a configuration diagram of the liquid crystal projection television of the present invention. However, components that are unnecessary for the description are omitted. In FIG. 6, reference numeral 61 denotes a condensing optical system, which has a concave mirror and a light generating means 2 inside.
It has a 50W metal halide lamp. 62 is a U that transmits infrared rays and ultraviolet rays and reflects only visible light
It is a VIR cut mirror. However, it goes without saying that the UVIR cut mirror 62 may be arranged inside the condensing optical system 61. Also, 63a is BDM and 63b is G.
DM and 63c are RDMs. It is needless to say that the arrangement of the BDM 63a to the RDM 63c is not limited to the above order, and the last RDM 63c may be replaced with a total reflection mirror.

Reference numerals 64a, 64b and 64c are liquid crystal panels of the present invention. Of the liquid crystal panels, the liquid crystal panel 64c that modulates the R light has a larger water droplet liquid crystal particle diameter or a larger liquid crystal film thickness than other liquid crystal panels. This is because the longer the wavelength of light, the lower the scattering characteristics. The particle size of the water-drop liquid crystal can be controlled by controlling the intensity of ultraviolet light during polymerization or by changing the material used. The liquid crystal film thickness can be adjusted by changing the bead diameter. Also, the apparent height of the protrusion pattern 15 is red (R), green (G), and blue (B).
It may be changed for each liquid crystal panel for use.
In that case, the height of the portion having the refractive index A of the liquid crystal panel for R is highest, and the height for B is preferably low. 65a, 65b, 6
5c, 67a, 67b, 67c are lenses, 66a, 66
b and 66c are apertures as a diaphragm.
Note that 65, 66, and 67 form a projection optical system. Also, as long as there is no particular problem, 65, 66 and 67
Is called a projection lens system. It is also clear that the aperture 66 is not necessary when the F value of the lens 65 and the like is large, and it is also clear that the projection lens system can be replaced by one lens.

The arrangement and the like of the projection lens system are as follows. First, the distance L between the polymer dispersed liquid crystal panel 64 and the lens 65 of the liquid crystal display device, the lens 65 and the aperture 66.
Are arranged so that the distances to are almost equal. The projection lens system allows parallel rays that have passed through each liquid crystal panel to pass through,
It plays the role of blocking the light scattered by each liquid crystal panel.
As a result, high-contrast full-color display can be realized on the screen. The contrast is improved by reducing the aperture diameter D of the aperture. However, the image brightness on the screen is reduced.

The film thickness of the liquid crystal layer of the liquid crystal panel of the present invention is 1
When 0 to 15 μm, the optimal condensing angle of the lens is around 6 degrees, and at that time, the contrast is 150: 1 at the center of the screen.
Thus, when projected on a 40-inch screen with a rear system television, the screen gain was 300 [ft] or more, and a screen brightness equal to or higher than that of the CRT projection television could be obtained.

The operation of the liquid crystal projection television of the present invention will be described below. Since the R, G, and B light modulation systems have substantially the same operation, the B light modulation system will be described as an example. First, white light is emitted from the condensing optical system 61, and the B light component of the white light is BDM6.
It is reflected by 3a. The B light is incident on the polymer dispersed liquid crystal panel 64a. As shown in FIGS. 8A and 8B, the polymer-dispersed liquid crystal panel controls the scattering and transmission states of incident light according to the signal applied to the pixel electrode, and modulates the light.

The scattered light is blocked by the aperture 66a, and conversely, the light within a predetermined angle passes through the aperture 66a. The modulated light is enlarged and projected on a screen (not shown) by the projection lens 67a. As described above, the B light component of the image is displayed on the screen. Similarly, the polymer dispersed liquid crystal panel 64b modulates the light of the G light component, and the polymer dispersed liquid crystal panel 64c modulates the light of the R light component to display a color image on the screen.

The projection lens system in FIG. 6 is not limited to this. For example, a central shield type optical system in which parallel light is shielded by a light shield and scattered light is projected on the screen may be used. Needless to say.

Further, in (FIG. 6), light is emitted from the counter substrate 1.
Although the light is incident from the first side, the present invention is not limited to this, and it is obvious that the same effect can be obtained even when the light is incident from the array substrate 12. As described above, the liquid crystal panel and the liquid crystal projection television of the present invention do not depend on the incident direction of light.

Furthermore, in the embodiment of the liquid crystal projection type television of the present invention, it is expressed as a rear type liquid crystal projection type television, but the present invention is not limited to this, and it is a front type liquid crystal projection type which projects an image on a reflection type screen. It goes without saying that you can use TV. Further, in the liquid crystal projection television of the present embodiment, the color separation is performed by the dichroic mirror, but the present invention is not limited to this. For example, an absorption type color filter may be used to perform the color separation.

In the liquid crystal projection television of this embodiment, one projection lens system is provided for each of the R, G, and B light modulation systems, but the invention is not limited to this, and, for example, a mirror or the like. It goes without saying that a configuration may be adopted in which the display images modulated by the liquid crystal panel are combined into one by using, and are made incident on one projection lens system and projected. Furthermore, it is not limited to providing three liquid crystal panels that modulate R, G, and B lights. For example, a full-color image can be realized on a television that projects an image on the panel by attaching a mosaic color filter to one liquid crystal panel.

Further, although the liquid crystal panel of the present invention has been described as a transmissive liquid crystal panel, the present invention is not limited to this, and it may be formed as a reflective type. In that case, the pixel electrode may be made of a metal substance and used as a reflective electrode.

Further, the optical system is not limited to the one shown in FIG. 6 and a Schlieren optical system may be used. The block diagram is shown in (FIG. 7). As the light modulation element, the liquid crystal panel of the present invention described above is used in a reflective structure.
The projection light emitted from the projection light source 73 is generated by the condenser lens 7
At 4, the mirror 72 is focused. The focused light is reflected by the mirror 72, becomes parallel rays by the schlieren lens 75, and enters the liquid crystal panel 66 of the present invention. Light incident on a pixel in which the portion having the refractive index A is completely generated is refracted, enlarged by the schlieren lens 75, and projected on the screen 71. The light incident on the pixel in which the portion having the refractive index A has completely disappeared is reflected as it is, and is shielded by the mirror / Schlieren stop 72. In the intermediate state between the generation and disappearance of the portion having the refractive index A, the light depending on the refractive state is projected on the screen 71. Although the refracted light in the liquid crystal projection television is projected on the screen by the schlieren lens 65, the invention is not limited to this, and the schlieren optical system in which the refracted light is blocked by the schlieren stop is configured. It goes without saying that it is okay.

Although the projection pattern 15 is formed in a matrix, it is not limited to this and may be formed in a stripe. In that case, a striped pattern is formed along the source signal line or the gate signal line, above the signal line and on the counter electrode.

[0041]

As described above, since the liquid crystal panel of the present invention uses the polymer-dispersed liquid crystal, it is possible to obtain a high-brightness screen which is more than twice as bright as the liquid crystal panel using the TN liquid crystal. Moreover, since no polarizing plate is used, naturally, there is no deterioration of the polarizing plate, which is a conventional problem. Further, the liquid crystal panel is not heated and the life is not shortened. Further, since an alignment film is unnecessary and rubbing treatment is not necessary, the manufacturing cost can be reduced.

Further, a refractive index distribution is formed in the liquid crystal layer by using the liquid crystal panel manufacturing method of the present invention in the liquid crystal panel,
Since it has a lens function, the amount of straight transmission of light in the off state of the liquid crystal can be significantly reduced due to the scattering effect in the liquid crystal layer and the refraction effect of the lens. Since the lens disappears when the liquid crystal is on, the incident light goes straight on. Therefore, a contrast of 100 or more can be achieved,
It is possible to realize high-quality image display with very good gradation display characteristics.

Further, the maximum height of the protrusion pattern is located above the signal line. Therefore, it is difficult to apply a voltage to the signal line. In the past, light was modulated on the signal line regardless of the image display, and the image display was deteriorated. However, since the liquid crystal panel of the present invention is difficult to apply a voltage in the upper layer of the signal line, it is not optically modulated and the image display is deteriorated. Less is.
The black matrix is not necessary, and the aperture ratio of the pixel is improved.

In the liquid crystal projection television of the present invention, since the liquid crystal panel of the present invention is used, it is possible to realize high brightness of image quality and high contrast display. Further, in the liquid crystal projection television of the present invention, the average particle diameter or the pore diameter of the water droplet liquid crystal is changed or the height of the apparent projection pattern is changed in accordance with the R, G, and B wavelengths. By doing so, the contrast at each wavelength is significantly improved, and high quality image display can be realized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a liquid crystal panel according to an embodiment of the present invention.

FIG. 2 is a plan view of a counter electrode substrate of a liquid crystal panel according to an embodiment of the present invention.

FIG. 3A of the counter electrode substrate of the liquid crystal panel shown in FIG.
It is sectional drawing in the -A 'line.

FIG. 4 is an explanatory diagram of a liquid crystal panel of the present invention.

FIG. 5 is a cross-sectional view of another embodiment of the counter electrode substrate of the liquid crystal panel of the present invention.

FIG. 6 is a configuration diagram of an embodiment of the liquid crystal projection television of the present invention.

FIG. 7 is a configuration diagram of another embodiment of the liquid crystal projection television of the present invention.

FIG. 8 is an explanatory diagram of the operation of the polymer dispersed liquid crystal panel.

FIG. 9 is an equivalent circuit diagram of a liquid crystal panel.

FIG. 10 is a cross-sectional view of a conventional liquid crystal panel.

FIG. 11 is a configuration diagram of a conventional liquid crystal projection television.

[Explanation of symbols]

 11,86 Counter electrode substrate 12,81 Array substrate 13 82 Pixel electrode 14 87 Source signal line 15,51 Convex pattern 16,83 Counter electrode 17 Polymer dispersed liquid crystal 61,111 Condensing optical system 62,112 UVIR cut mirror 64a, 64b, 64c, 76 Polymer dispersed liquid crystal panel 66a, 66b, 66c Aperture 73 Projection light source 74 Condenser lens 75 Schlieren lens 77, 78 Pixel 84 Water-drop liquid crystal 85 Polymer 93 TFT 94 Additional capacitor 95 Liquid crystal 102 Black matrix 103 TN liquid crystal 115a, 115b, 115c TN liquid crystal panel

Claims (9)

[Claims] 1. A pattern of at least one of a convex shape and a concave shape made of a dielectric material is formed on the counter electrode of the counter electrode substrate and at a position substantially facing the signal line on the array substrate on which the pixel electrode is formed. A liquid crystal panel formed by sandwiching a polymer-dispersed liquid crystal between the counter electrode substrate and the array substrate. 2. The liquid crystal panel according to claim 1, wherein the pattern has at least one of a stripe shape and a matrix shape. 3. The liquid crystal panel according to claim 1, wherein the polymer-dispersed liquid crystal has a plurality of refractive index portions, and the portions having different refractive index are periodically repeated. 4. A first step of forming at least one of a convex shape and a concave shape made of a dielectric material on a counter electrode on a counter electrode substrate, and the pattern is formed on an array substrate. A second step of bonding the counter electrode substrate and the array substrate at a predetermined interval so as to be substantially opposed to the signal line, and a third step of injecting a resin containing liquid crystal between the counter electrode substrate and the array substrate. And a fourth step of applying a predetermined voltage to the counter electrode and curing the resin by using at least one of a light irradiation means and a heating means. 5. The method for manufacturing a liquid crystal panel according to claim 4, wherein the resin is an ultraviolet curable resin. 6. A liquid crystal panel according to claim 1, a light generating means, a first optical element part for guiding the light generated by the light generating means to the liquid crystal panel, and a light modulated by the liquid crystal panel. A liquid crystal projection type television characterized by comprising a second optical element part for projecting. 7. The light generated by the light generating means is split by a color filter into light of three predetermined wavelengths, blue light, green light and red light, and the liquid crystal panel has a wavelength of the three predetermined wavelengths. The liquid crystal projection television according to claim 6, wherein the liquid crystal projection television is arranged for at least one of the lights. 8. The liquid crystal projection television according to claim 7, wherein the color filter is a dichroic mirror. 9. An optical element for forming an optical image of a liquid crystal panel that modulates blue light, an optical image of a liquid crystal panel that modulates green light, and an optical image of a liquid crystal panel that modulates red light.
8. The liquid crystal projection television according to claim 7, wherein the images are projected on the same position on the screen.