JP2844986B2 - Light valve type projector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light valve, and more particularly to a light valve type projection device for enlarging and projecting an image displayed on a small liquid crystal panel onto a screen.

[0002]

2. Description of the Related Art In recent years, home theaters, presentations, and large-screen displays have been attracting attention. Many types of projection devices using light valves have been proposed in the past, but recently a liquid crystal projection device that obtains a large screen display image by enlarging and projecting the display image of a small liquid crystal panel with a projection lens etc. has been commercialized. Have been.

First, a conventional liquid crystal projector will be described with reference to the drawings. FIG. 16 is a configuration diagram of a conventional liquid crystal projection device. In FIG. 16, 141 is a condensing optical system, 142 is an infrared cut mirror that transmits infrared rays, 143a is a blue light reflecting dichroic mirror (hereinafter, referred to as BDM), and 143b is a green light reflecting dichroic mirror (hereinafter, GDM). 143c are red light reflecting dichroic mirrors (hereinafter referred to as RDMs),
44a, 144b, 144c, 146a, 146b, 1
46c is a polarizing plate, 145a, 145b, 145c are transmission type conventional TN liquid crystal panels, 147a, 147b, 14
7c is a projection lens system. Note that components unnecessary for the description, such as a field lens, are omitted from the drawings.

The operation of the conventional liquid crystal projection device will be described below with reference to FIG. First, white light emitted from the condensing optical system 141 reflects blue light (hereinafter referred to as B light) by the BDM 143a, and this B light is incident on the polarizing plate 144a. The light transmitted through the BDM 143a is reflected by the GDM 143b so as to reflect green light (hereinafter, referred to as G light), and is reflected by the polarizing plate 144b, and by the RDM 143c, by reflecting red light (hereinafter, referred to as R light).
44c.

Each liquid crystal panel modulates the transmitted light according to a video signal. The modulated light passes through the polarizing plates 146a, 146b, 146c according to the degree of modulation, enters the projection lens systems 147a, 147b, 147c, and is enlarged and projected on a screen (not shown) by the lens systems. .

Next, a general liquid crystal panel will be described. FIG. 17 is a plan view of the liquid crystal panel. (Figure 1
7), reference numeral 151 denotes a glass substrate (hereinafter, referred to as an array substrate) on which a thin film transistor (hereinafter, referred to as a TFT) as a switching element is formed, and 152 denotes an IT substrate.
A substrate on which a transparent electrode made of O or the like is formed (hereinafter, referred to as a counter substrate) 156 is a drive IC (hereinafter, referred to as a drive IC) for applying a signal for controlling on / off of a TFT connected to a gate signal line on the array substrate 151. 155, a drive IC for applying a data signal to a source signal line on the array substrate 151 (hereinafter, referred to as a source drive IC); 153, a polarizing film;
Is a sealing resin for sealing the liquid crystal. After that,
Those denoted by the same reference numerals have the same content, the same configuration, or an approximate one.

FIG. 18A is a plan view of one pixel portion of a conventional liquid crystal panel. FIG. 18B is a cross-sectional view taken along line DD ′ of FIG. 18A. However,
In the drawings, unnecessary portions are omitted for ease of explanation, and the drawings are modeled. The above applies to the following drawings.

In FIGS. 18A and 18B, reference numeral 52 denotes a source signal line, one end of which is connected to a source drive IC 1
55. Reference numeral 51 denotes a gate signal line, one end of which is connected to the gate drive IC 156.
Reference numeral 26 denotes an array substrate on which a first electrode, that is, a pixel electrode 24 made of ITO is formed. Further, a black matrix 27 is formed. In FIG. 19, 21
Is a counter substrate, and 171 is a layer composed of TN liquid crystal (hereinafter referred to as TN liquid crystal).
(Referred to as a liquid crystal layer), and its film thickness is about 5 μm.
An alignment film (not shown) made of an organic material such as a polyimide resin is formed on the counter electrode 22 and the pixel electrode 14. Note that the size of one pixel is about 500 μm to 30 μm.

FIG. 20 shows a conventional liquid crystal panel, TN.
FIG. 3 is a diagram illustrating the operation of a liquid crystal panel. In FIG. 20, 181 is a polarizing plate, 182 is a polarization direction, 183 is a transparent electrode, 184 is a liquid crystal molecule, 185 is a signal source, and 186 is a switch. As shown in FIG. 20, the incident light rotates 90 degrees in the off state, and transmits without rotating in the on state. Therefore, if the polarization directions of the two polarizing plates 181 are orthogonal, light is transmitted in the off state and is blocked in the on state. However, the opposite is true if the polarization directions are parallel to each other. The polarizing plate transmits only one of the longitudinal wave component and the transverse wave component, and irradiates each liquid crystal panel with the polarization direction of the light aligned. At this time, 50% or more of the light is absorbed by the polarizing plate, and the brightness of the transmitted light is reduced to half or less at the maximum. As described above, the TN liquid crystal panel modulates light to display an image.

[0010]

As apparent from the above description, in a liquid crystal panel using a TN liquid crystal, it is necessary to make linearly polarized light incident on the liquid crystal panel. Therefore, it is necessary to arrange polarizing plates before and after the liquid crystal panel. The above-described polarizing plate theoretically absorbs 50% or more of the light. Therefore, as a conventional problem, when a TN liquid crystal panel is used as a light valve and enlarged projection is performed on a screen, only a low-luminance screen can be obtained. In order to solve the above problems, the present invention uses a polymer dispersed liquid crystal panel as a light valve. Since a liquid crystal panel using a polymer-dispersed liquid crystal does not use a polarizing plate, the light use efficiency can be extremely increased.

Hereinafter, 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 the liquid crystal and the polymer. One is a type in which a liquid crystal in the form of water droplets is dispersed in a polymer. The liquid crystal exists in a discontinuous state in the polymer. Since then, such liquid crystals have been converted to PDLC (Polymer Dispersed Liquid Crys).
tal), and a liquid crystal panel using the liquid crystal is referred to as P
It is called D liquid crystal panel. The other type adopts a structure in which a polymer network is stretched around a liquid crystal layer. It looks just like a sponge with liquid crystal. Liquid crystals exist continuously without being in the form of water droplets. Since then, such liquid crystals have been converted to PNLC (Polymer Network Liquid Cryst
al), and a liquid crystal panel using the liquid crystal is called a PN liquid crystal panel. In order to display an image on the two types of liquid crystal panels, scattering and transmission of light are controlled.

The PD liquid crystal panel utilizes the property that the refractive index differs in the direction in which the liquid crystal is oriented. In the state where no voltage is applied, the respective liquid crystal droplets are oriented in an irregular direction. In this state, a difference in refractive index occurs between the polymer and the liquid crystal, and the incident light is scattered. Here, when a voltage is applied, the alignment directions of the liquid crystals are aligned. If the refractive index when the liquid crystal is aligned in a certain direction is adjusted in advance to the refractive index of the polymer, incident light is transmitted without being scattered.

On the other hand, the PN liquid crystal panel uses the irregularity of the alignment of liquid crystal molecules. Irregular orientation state,
That is, the incident light is scattered when no voltage is applied. On the other hand, when a voltage is applied to make the arrangement state regular, light is transmitted. The above description of the movement of the liquid crystal of the PD liquid crystal panel and the PN liquid crystal panel is based on a model. Although the present invention is not limited to one of a PD liquid crystal panel and a PN liquid crystal panel, a PD liquid crystal panel will be described as an example for ease of explanation.
The PD liquid crystal panel and the PN liquid crystal panel are collectively referred to as a polymer dispersed liquid crystal panel. Further, liquids containing liquid crystal to be injected into the polymer dispersed liquid crystal panel are collectively referred to as a liquid crystal solution or a resin, and a state in which a resin component in the liquid crystal solution is polymerized and cured is referred to as a polymer.

The polymer matrix in the polymer-dispersed liquid crystal layer serving as the liquid crystal layer of such a dispersion type liquid crystal display element may be a thermoplastic resin or a thermosetting resin as long as it is basically transparent. Although not available, UV-curable resins are the simplest, have good performance, and are commonly used. The reason is that the conventional method of manufacturing a TN mode liquid crystal panel can be applied as it is. As a conventional method of manufacturing a liquid crystal panel, first, a predetermined electrode pattern is formed in advance on two upper and lower substrates, and the two substrates are overlapped so that the electrodes face each other. At this time, a spacer having a predetermined size and a uniform particle size is sandwiched between the substrates, and the two substrates are fixed with an epoxy resin sealing material in a state where a gap between the two substrates can be maintained. Next, a manufacturing method of injecting a liquid crystal into the empty cell thus obtained is often used.

In order to manufacture a dispersion type liquid crystal panel by applying this manufacturing method, if the material of the polymer matrix is a UV-curable resin, particularly, for example, an acrylic resin is used as an example, before the injection, Is a monomer or /
And a low-viscosity precursor such as oligomers and oligomers, and the blend with liquid crystal has sufficient fluidity to be injected at room temperature. If a method of forming a polymer-dispersed liquid crystal layer by irradiating light to advance a curing reaction later is used, a dispersion-type liquid crystal panel can be easily produced.

When the panel is irradiated with ultraviolet light after the injection, only the resin causes a polymerization reaction to become a polymer, and only the liquid crystal is phase-separated. Are formed. On the other hand, when the amount of the liquid crystal is large, the polymer matrix exists in the liquid crystal material in the form of particles or a network, and the liquid crystal is formed so as to form a continuous layer. At this time, unless the particle size of the liquid crystal droplet 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 light scattering performance is poor and the contrast does not increase. For this purpose, the material must be a material that can be cured in a relatively short time, and an ultraviolet curable resin is desirable.

The operation of the polymer dispersed liquid crystal panel will be briefly described with reference to FIGS. 21 (a) and 21 (b). (FIG. 21
(A) (b)) is an explanatory view of the operation of the polymer dispersed liquid crystal panel. In FIGS. 21A and 21B, reference numeral 191 denotes an array substrate, 192 denotes a pixel electrode, 193 denotes a counter electrode,
4 is a liquid crystal in the form of water droplets, 195 is a polymer, and 196 is a counter substrate. A TFT or the like is connected to the pixel electrode 192, and TF
A voltage is applied to the pixel electrode by turning T on and off, and the direction of liquid crystal alignment on the pixel electrode is changed to modulate light.
When no voltage is applied as shown in FIG. 21 (a), each liquid crystal 194 is oriented in an irregular direction. In this state, a difference in refractive index occurs between the polymer 195 and the liquid crystal, and the incident light is scattered. Here (FIG. 21)
As shown in (b)), when a voltage is applied to the pixel electrode, the directions of the liquid crystals are aligned. If the refractive index when the liquid crystal is aligned in a certain direction is adjusted in advance to the refractive index of the polymer, incident light is emitted from the array substrate 191 without being scattered.

As described above, since the polymer-dispersed liquid crystal panel does not use a polarizing plate, the light utilization efficiency is high and a display image with extremely high luminance can be obtained. However, there are the following problems when trying to use the liquid crystal for a liquid crystal panel.

In order to put this polymer dispersed liquid crystal panel into practical use as a device, it is required that it can be driven at a low voltage and that it has a sufficient contrast ratio. The contrast ratio for obtaining particularly good display is preferably 30: 1 or more for a direct view type and 100: 1 or more for a projection type. In order to increase the contrast ratio, it is necessary to enhance the light scattering characteristics. Increasing the thickness of the polymer-dispersed liquid crystal layer improves the light scattering performance, but increases the driving voltage and causes a problem that TFT driving becomes difficult. One possible target for the scattering effect is complete diffusion. The contrast ratio CR in perfect diffusion is CR = 1 / sin ² σ
Can be calculated by For example, S.I.D. Bulletin Vol. 18 (1977) pp. 134-146 (Projection Sys.
tems for Light Valves, Proceeding of the S, I, D, vo1,
18/2, Second Quarter, 1977, P.134-P.146). Where σ is the converging angle (half angle). This indicates that the contrast improves when the condensing angle of the projection lens is reduced, that is, when the F-number is increased.

When used as a projection type display, the F-number of a concave mirror condensing optical system using a metal halide lamp, which is widely used at present, and a projection optical system that matches the concave mirror condensing optical system are 4 to 5, indicating a high diffused state indicating a perfect diffusion state. Even when a molecular dispersion liquid crystal panel is used, the contrast ratio is insufficient at 65: 1 according to the above formula.

An uneven cross-section layer is formed on at least one of the array substrate and the counter substrate of the liquid crystal panel on a surface facing the liquid crystal layer, and the uneven cross-section layer is used as a diffraction grating. When the difference in the refractive index between the liquid crystal layer and the concavo-convex sectional shape layer is eliminated by control, the diffraction effect is eliminated, and a method of displaying by controlling the diffraction effect so that the diffraction effect appears according to the refractive index difference has been proposed. (JP-B-53-3928). In general, an optical device of a light valve using diffraction uses black display when the diffraction grating is erased (light travels straight) and white display during diffraction in order to obtain good black display. However, since the light utilization factor of white display strongly depends on the shape of the diffraction grating, wavelength bandwidth, etc., it is necessary to strictly control the shape of the diffraction grating to obtain a high light utilization factor. Since it largely depends on the uniformity of the shape, the light utilization is high and the uniform white /
It is not easy to manufacture a panel showing a black display. The grating pitch of the diffraction grating corresponding to the F-numbers 4 to 5 of the projection optical system is approximately several μm, and the difference between the extraordinary refractive index and the ordinary refractive index of the liquid crystal is at most about 0.2 at most and the 0th order. The grating height at which the efficiency of folding light becomes zero is several μm, and it is not easy to form such an uneven shape.

[0022]

Means for Solving the Problems TN is used as a light valve.
When a liquid crystal panel is used, 50% or more of the light is absorbed by the polarizing plate. Therefore, there is a problem that the light utilization rate is low and high-luminance display cannot be performed. Therefore, in the present invention, a polymer dispersed liquid crystal panel is used as a light valve.

A light valve type projection apparatus according to the present invention comprises a light generating means, a light valve for modulating the light generated by the light generating means as a change in a scattering state, and a projection for projecting the light modulated by the light valve. Means, a first mask disposed between the light generating means and the light valve, a second mask disposed between the projection means and the light valve, the first mask comprising an imaging means which is disposed between the mask and the second mask, the imaging hands
The projection image of the opening of the first mask by the step coincides with the opening of the second mask. Further, the light valve type projection device of the present invention includes a light source, a polymer dispersed liquid crystal panel, and a projection lens for projecting light modulated by the polymer dispersed liquid crystal panel, wherein the light source, the liquid crystal panel, A first mask disposed between the first mask and an image of the light source formed in an opening of the first mask, the first mask including a plurality of lenses similar in shape to an effective display area of the liquid crystal panel; A lens array, a second lens array that is arranged near the first mask and forms an image of the first lens array on the liquid crystal panel, and is arranged between the projection lens and the liquid crystal panel. A second mask, and an imaging lens disposed between the first mask and the second mask, wherein the projection image of the opening of the first mask by the imaging lens is the second mask. Formed on the second mask,
In addition, it coincides with the opening of the second mask.

In the present invention, a polymer dispersed liquid crystal panel is used as a light valve. Further, a polymer dispersed liquid crystal panel in which a concave-convex section layer functioning as a diffraction grating is formed in a pixel region that modulates light of at least one of the array substrate and the counter substrate may be used. The refractive index of the material forming the uneven cross-sectional shape layer is such that the refractive index of the material of the liquid crystal layer is substantially the same as that of the polymer.

In a polymer dispersed liquid crystal panel arranged for light of each wavelength, the thickness of one or more polymer dispersed liquid crystal layers of the polymer dispersed liquid crystal panel and the average particle diameter or average pore diameter of liquid crystal droplets are determined. At least one of the height and pitch of the unevenness of the uneven layer formed in the polymer dispersed liquid crystal panel is designed to be different from other polymer dispersed liquid crystal panels.

[0026]

In the light valve type projection apparatus of the present invention, when the polymer dispersed liquid crystal panel is in the light transmitting state (transparent state), the first state is obtained.
The light that has passed through the mask passes through the light valve as it is, and is incident on the opening of the second mask by the imaging lens,
Projected to give a white display. Since the aperture of the first mask and the aperture of the second mask coincide with each other by the imaging lens, light is not largely blocked by the second mask during white display. Further, when a lens array including a plurality of lenses is used, light blur due to the first mask can be eliminated, so that light utilization can be improved. Further, by using the second lens array near the first mask, a display with uniform brightness can be obtained. When the polymer-dispersed liquid crystal panel is in a cloudy state (scattered state), light passing through the first mask is scattered by the light valve, and scattered light picked up at a converging angle corresponding to the F number of the optical system is projected. Although the light passes through the exit pupil of the system, in the present invention, since the exit pupil is shaded by the second mask, the light-shielding effect is significantly improved, and a good black display can be obtained. In other words, the F number of the projection lens is determined by the sum of the opening areas of the second mask, and the F number of the projection lens in this case is the second number.
Larger than the case without the mask, and can shield more scattered light. At this time, the higher the scattering power of the polymer-dispersed liquid crystal, the smaller the amount of light passing through the opening of the second mask,
It goes without saying that the black quality is improved. In the present invention, the polymer dispersed liquid crystal panel is further provided with a diffraction grating that can be generated and erased. Thereby, the black quality can be further improved.

The operation of the diffraction grating will be described. A layer having an uneven cross section is formed of a light transmitting material having a refractive index equal to or near the refractive index np of the polymer. The refractive index of the light transmitting material is nt. Further, the ordinary light refractive index of the liquid crystal is no, the extraordinary light refractive index is ne, and np = no. (FIG. 21
As shown in (a), when in the off state, the refractive index nx of the liquid crystal layer as a whole indicates a refractive index in which the refractive index np of the polymer and the refractive index no · ne of the liquid crystal are superimposed. Since the refractive indexes nt and nx of the uneven cross-sectional shape layer are different, there is a difference in refractive index between the two. Light incident on the liquid crystal panel is diffracted by the uneven cross-sectional shape layer, and the number of components traveling straight decreases. In other words, the uneven cross-sectional shape layer acts as a diffraction grating (hereinafter, the uneven cross-sectional shape layer is referred to as a diffraction grating). By providing a grating pitch so that the diffracted light just reaches the light-shielding portion of the second mask, the light passing through the second mask is drastically reduced, and an extremely good black display is achieved.

As shown in FIG. 21 (b), when in the ON state, the liquid crystal molecules are arranged in a certain direction, and np = no = na. Therefore, np = nt = na. This means that there is no difference between the refractive index na of the liquid crystal layer and the refractive index nt of the diffraction grating. Accordingly, since the state is the same as when no diffraction grating is formed, the incident light goes straight as it is, and there is no loss of light in white display. Also, the formation of the diffraction grating means that irregularities are formed on the counter electrode or the pixel electrode. This enhances the adhesion between the liquid crystal layer and the electrodes. If a light transmitting material is selected as the material of the diffraction grating, the aperture ratio of the pixel does not decrease.

Also, by forming a triangular wave or sawtooth cross-sectional shape layer and using the refraction at the interface to bend the angle of the light beam, an inclined surface is provided so that the refracted light just reaches the light shielding portion of the second mask. As a result, light passing through the second mask is drastically reduced, and an extremely good black display is achieved.
Also, if the refractive index of the triangular wave or sawtooth cross-sectional shape layer is made to match the refractive index of the liquid crystal in the same manner as described above, the incident light goes straight as it is in the ON state, and there is no light loss in white display.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a light valve type projection device according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic view conceptually showing a principle configuration of a light valve type projection device of the present invention. An active matrix type polymer dispersed liquid crystal panel (hereinafter referred to as a liquid crystal panel) 11 is used as a light valve, and a metal halide lamp and a concave mirror 18 are used as a light source 15 as a light generating means. The concave mirror 18 is provided for condensing the light from the light source 15 and increasing the light utilization rate. Even if the concave mirror 18 is not provided, it does not impair the gist of the present invention. An image forming lens (hereinafter referred to as a schlieren lens) 14 is provided between the input mask 12 having a large number of openings and the output mask 13 so that an image of the input mask 12 is formed on the output mask 13. A Schlieren optical system is configured, and the liquid crystal panel 11 is arranged in the Schlieren optical system. In the present invention, the schlieren lens 1
4 is provided between the input mask 12 and the liquid crystal panel 11, but may be provided between the liquid crystal panel 11 and the output mask 13. Light from a light source 15 as a light generating means is incident on the liquid crystal panel 11 via the input mask 12 and the schlieren lens 14 of the schlieren optical system. The image formed on the liquid crystal panel 11 is projected on a screen 17 via a projection lens 16. Although the projection lens 16 as the projection means is schematically illustrated as a single lens in the drawing, it is actually a projection lens group including a plurality of lenses. Further, the output mask 13 may be arranged near the pupil position of the projection lens group. The light is scattered by the liquid crystal panel 11 in accordance with the projected image, but the scattered light is blocked by the light shielding portion of the output mask 13 and does not reach the screen 17.

A sectional view of the liquid crystal panel 11 used as a light valve in this embodiment is shown in FIG. Array substrate 26, counter substrate 2 at least one of which is transparent
A pixel electrode 24 and a counter electrode 22 are respectively formed on the substrate 1 by a transparent electrode such as ITO. 25 is a thin film transistor (TFT) as a switching element, and 27 is a black matrix. The configuration of the array substrate 26 is substantially the same as the configuration of the conventional example (FIG. 18A), and thus the description is omitted. A polymer dispersed liquid crystal layer 23 is sandwiched between the two substrates. The thickness of the polymer dispersed liquid crystal layer 23 is 5 μm or more.
The range is preferably 25 μm, and more preferably 8 μm to 15 μm. This is because when the film thickness is 20 μm or more, a high voltage is required for driving, while when the film thickness is 8 μm or less, the scattering characteristics deteriorate and the contrast becomes low.

The liquid crystal material used for the liquid crystal panel of the present invention is preferably a nematic liquid crystal, a smectic liquid crystal, or a cholesteric liquid crystal, and may be a single or two or more liquid crystal compounds or a mixture containing a substance other than the liquid crystal compound. Good. In addition, among the liquid crystal materials described above, a cyanobiphenyl-based nematic liquid crystal having a relatively large difference between the extraordinary light refractive index ne and the ordinary light refractive index no is most preferable. As the polymer matrix material, a transparent polymer is preferable. As the polymer, any of a thermoplastic resin, a thermosetting resin, and a photocurable resin may be used. In view of the above, it is preferable to use an ultraviolet curing type resin. As a specific example, an ultraviolet curable acrylic resin is exemplified, and a resin containing an acrylic monomer or acrylic oligomer which is polymerized and cured by irradiation with ultraviolet light is particularly preferable.

As such a polymer-forming monomer,
2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, neopentyl glycol acrylate, hexanediol diacrete, diethylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol acrylate, and the like.

Examples of the oligomer or prepolymer include polyester acrylate, epoxy acrylate, and polyurethane acrylate.

Further, a polymerization initiator may be used in order to quickly carry out the polymerization. For example, 2-hydroxy-2-
Methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-
ON ("Darocure 1116" manufactured by Merck Ltd.), 1-bidroxycyclohexylphenylketone ("Irgacure 184" manufactured by Ciba-Gaiky), benzyl methyl ketal ("Irgacure 651" manufactured by Ciba-Geigy) and the like are listed.

In addition, a chain transfer agent, a photosensitizer, a dye, a crosslinking agent, and the like can be appropriately used as optional components.

A liquid or viscous material obtained by uniformly dissolving a liquid crystal material in the ultraviolet curable compound is injected between two substrates, and then irradiated with ultraviolet light to cure only the ultraviolet curable compound. At this time, only the liquid crystal material undergoes phase separation to form a polymer dispersed liquid crystal layer.

Although the proportion of the liquid crystal material in the polymer dispersed liquid crystal layer is not specified here, it is generally 20 to 90% by weight.
Degree is good, preferably about 50% by weight to 70% by weight. If it is less than 20% by weight, the amount of liquid crystal droplets is small, and the scattering effect is poor. When the content is 90% by weight or more, the polymer and the liquid crystal tend to be phase-separated into upper and lower layers, the ratio of the interface is reduced, and the light scattering is reduced. The structure of the polymer-dispersed liquid crystal layer changes depending on the liquid crystal fraction. At about 50% by weight or less, liquid crystal droplets exist as independent droplets, and at 50% by weight or more, a continuous phase is formed in which the polymer and the liquid crystal are intertwined with each other. .

FIGS. 3A and 3B are schematic plan views of the input mask 12 and the output mask 13 used in the present invention. The shapes of the openings 31 and 32 are not limited to those in the embodiment, and the number is the same. The image of the opening 31 of the input mask 12 formed by the schlieren lens 14 by the light generated from the light source 15 is used as the output mask. It suffices if it is designed to match the opening 32 of the thirteen.

As the light source 15, a halogen lamp, a metal halide lamp, a xenon lamp, or the like is used. In the present invention, the concave mirror 18 is arranged to increase the light collection efficiency, but this is another means such as a condenser lens. No problem.

FIG. 4 is a schematic diagram showing a distribution state of light intensity on an output mask by a liquid crystal panel in the light valve type projection apparatus of the present invention. With no voltage applied,
The outgoing rays are affected by scattering. In the figure, the light rays indicated by hatching are transmitted through the mask, and a black display is obtained. As the scattering performance of the liquid crystal panel increases, the amount of light in the hatched portion decreases, and the amount of light passing through the mask decreases, thereby improving the black quality. In addition, by applying a voltage, the liquid crystal panel enters a light transmitting state and displays white.

Hereinafter, a second embodiment of the light valve type projection apparatus according to the present invention will be described, but the description will be limited only to differences from the first embodiment. Therefore, items not described are the same as in the first embodiment. The same applies to the following other embodiments. FIG. 5A is a plan view of one pixel portion of a liquid crystal panel used as a light valve in the second embodiment of the present invention. (FIG. 5B)
It is sectional drawing in the AA 'line of (a)). FIG. 6 is a cross-sectional view when the counter substrate 21 is attached to the array substrate 26 shown in FIGS. 5A and 5B, and the polymer dispersed liquid crystal is injected between the two substrates. (FIGS. 5A and 5B)
In FIG. 6, reference numeral 51 denotes a gate signal line, 52 denotes a source signal line, and 53 denotes a layer having an uneven cross section (hereinafter referred to as a diffraction grating).
It is. However, in order to make the drawing easier to see, the counter electrode substrate and the like are omitted from FIG. 5A as in the conventional example. As described above, the drawings are modeled. For example, the number, width, shape, and the like of the diffraction grating correspond to this. That is, the number, width, and the like are not limited. Specifically, the pixel size is 200 to 30 μm,
The pitch P of the diffraction grating is 30 to 2 μm. Examples of the material of the diffraction grating include SiOx, SiNx, TaOx, inorganic substances such as glass-based substances, and organic substances such as polyimide and acrylic resin. The selection of the material is determined according to the refractive index of the polymer of the polymer dispersed liquid crystal layer 23. The refractive index of each material is ordinary light refractive index no of liquid crystal is 1.45.
-1.55, the extraordinary light refractive index ne of the liquid crystal is 1.65-1.
80, a polymer having a refractive index np of 1.45 to 1.55 is often used. In many cases, np = no.

When the liquid crystal having a positive dielectric constant is in the off state, the refractive index nx of the liquid crystal layer 23 is generally (2no + ne) / 3.
Indicated by Conversely, when the switch is in the ON state, it becomes no. Therefore,
In order for the diffraction grating to appear when the liquid crystal is in the off state and to disappear when the liquid crystal is in the on state, the refractive index n
It is sufficient that t = np or a value in the vicinity thereof. That is, when the liquid crystal is off, the refractive index nx of the liquid crystal layer
Is (2no + ne) / 3, so that nt ≠ nx, and a refractive index difference Δn occurs between the diffraction grating 53 and the liquid crystal layer 23. Conversely, when the liquid crystal is on, the refractive index of the liquid crystal layer is no,
If no = np, then nt = np. That is, the diffraction grating 5
3 and the liquid crystal layer 23 have no difference in refractive index. The difference between the refractive index nt of the diffraction grating and the refractive index NP of the polymer is preferably within 0.1, and a material within 0.1 should be selected.

From the above studies, it is considered that SiO2, which is easy to form and process in terms of process, is suitable as the current inorganic material as a material for forming the diffraction grating. The refractive index of SiO2 is usually about 1.45 to 1.50. Further, as a forming method, a pattern mask may be formed and etched after depositing SiO2. Alternatively, there is a method in which the film is directly formed on a glass substrate by photolithography and dry etching. As the organic material, it is optimal to use the same transparent polymer as that used for the liquid crystal layer 23. As a method of forming a diffraction grating using the above-described materials, application to a substrate using a roll quarter or a spinner or the like may be performed, and only a necessary portion may be polymerized using a pattern mask. There is also a method in which a photosensitive resin composed of a polymer and a dopant is spin-coated on a substrate, exposed through a pattern mask, and then subjected to dry development by sublimation of the dopant by heating under reduced pressure.

The pitch p and height d of the diffraction grating 53 vary considerably depending on the wavelength λ of the light to be modulated, the refractive index of the liquid crystal layer 23, the directivity of light of the optical system, the required diffraction efficiency, and the like. For example, as shown in FIG. 5, when the diffraction grating 53 has a rectangular cross-sectional shape, the diffraction angle θ and the efficiency η 0 of the 0th-order diffracted light are given as follows.

Sin θ = mλ / p (where m is the order of diffraction) η 0 = 0.5 * (1 + cos δ) (where δ = 2πΔnd / λ) Therefore, the pitch p and the height d are the directivity and diffraction of light of the optical system. It should be determined by the angle θ and the wavelength λ. However, it often depends on the process conditions for forming the diffraction grating. The pitch t is about 2 μm to 60 μm, and most preferably, 4 μm to 20 μm. Although the shape of the diffraction grating is often a sine curve or trapezoid due to the process, it may be designed in accordance with a desired diffraction grating and diffraction direction. There is no problem in its effect.

FIG. 7 is a schematic diagram showing the distribution of the light intensity on the output mask of the light beam modulated by the liquid crystal panel in the second embodiment of the present invention. With no voltage applied, the emitted light is affected by scattering and diffraction.
The amount of light that is blocked by the output mask is increased by the effect of diffraction more than in the liquid crystal panel used in the first embodiment of the present invention, and the black quality is improved.

In the second embodiment of the present invention, the diffraction grating 5
Although 3 is formed on the array substrate 26 side, it may be formed on the counter substrate 21 side as shown in FIG. (FIG. 8
(A) is a plan view of one pixel portion of a liquid crystal panel used as a light valve in the second embodiment of the present invention. (FIG. 8
FIG. 9B is a cross-sectional view taken along line BB ′ of FIG. 8A. FIG. 9 is a cross-sectional view when the array substrate 26 is attached to the opposing substrate 21 shown in FIGS. 8A and 8B and the polymer-dispersed liquid crystal is injected between the two substrates. Similar effects can be obtained by providing the diffraction grating 53 on the counter substrate 21 side as shown in FIG.

Although the pixel electrode 24 or the counter electrode 22 is formed on the diffraction grating 53 in the second embodiment of the present invention, the pixel electrode 24 or the counter electrode 22 may be formed below the diffraction grating 53. good.

Hereinafter, a third embodiment of the present invention will be described. (FIG. 10) is a sectional view of a liquid crystal panel used as a light valve in the third embodiment of the present invention. A triangular-wave cross-sectional shape layer 81 is formed on the array substrate 26.
The material and method for forming the triangular-wave cross-sectional shape layer 81 are formed in the same manner as the diffraction grating shown in the second embodiment of the present invention. However, the present invention does not use the diffraction effect, but uses the effect that light rays are refracted by the difference in the refractive index at the interface between the triangular-wave cross-sectional shape layer 81 and the liquid crystal layer 23.

When the liquid crystal having a positive dielectric constant is in the off state, the refractive index nx of the liquid crystal layer 23 is generally (2no + ne) / 3.
Indicated by Conversely, when the switch is in the ON state, it becomes no. Therefore,
Liquid crystal causes a refractive index difference at the interface when the off state, in order to eliminate the refractive index difference when the ON state, the refractive index nt = np = n _o of a diffraction grating or, to a value in the vicinity thereof do it. That is, when the liquid crystal is off, the refractive index nx of the liquid crystal layer is (2no + ne) / 3, so that nt ≠ nx
And the refractive index difference Δ between the triangular wave section shape layer 81 and the liquid crystal layer 23.
n occurs. In addition, since the triangular-wave sectional shape layer 81 is inclined at an angle with respect to the incident light beam, the light beam is emitted by being bent by an angle given by Snell's law. Conversely, when the liquid crystal is in the ON state, the refractive index of the liquid crystal layer is no. Therefore, if no = np, then nt = np. That is, there is no difference in the refractive index between the triangular wave section shape layer 81 and the liquid crystal layer 23.

FIG. 11 is a schematic diagram showing the distribution of the light intensity on the output mask of the light beam modulated by the liquid crystal panel in the third embodiment of the present invention. With no voltage applied, the emitted light is affected by scattering and refraction. The amount of light rays blocked by the output mask is increased due to the refraction effect as compared with the liquid crystal panel used in the first embodiment of the present invention, and the black quality is improved.

In the third embodiment of the present invention, the triangular-wave-shaped layer 81 is formed on the array substrate 26 side, but may be formed on the counter substrate 21 side as shown in the second embodiment.
Further, in the third embodiment of the present invention, the pixel electrode 24 or the counter electrode 22 is formed on the triangular-wave cross section layer 81, but the pixel electrode 24 or the counter electrode 22 is formed below the triangular-wave cross section layer 81. May be. Further, in the third embodiment of the present invention, a triangular-wave-shaped cross-sectional layer is used, but a saw-tooth-shaped cross-sectional layer having only one direction of inclination may be used.

Hereinafter, a fourth embodiment of the present invention will be described. (FIG. 12) is a schematic diagram conceptually showing a principle configuration of a light valve type projection device according to a fourth embodiment of the present invention. The light source 15 as a light generating means uses a metal halide lamp and a concave mirror 18. The concave mirror 18 condenses the light emitted from the lamp and does not impair the gist of the present invention even if it is not provided for improving the light utilization factor. A first lens array 109 (hereinafter, referred to as a fly-eye lens) is arranged between the light source 15 and the input mask 12. The fly-eye lens 109 is an aggregate of a plurality of lenses, and each lens forms an image of the light source 15. The light source image is designed and arranged so that the light source image is formed at the opening of the input mask 12 by the fly-eye lens 109. The opening of the input mask is provided so as to correspond to each lens of the fly-eye lens 109 on a one-to-one basis. Fly eye lens 109
Unnecessary illumination light generated in the above is shielded by the input mask 12. When the liquid crystal panel 11 is irradiated with unnecessary illumination light, unnecessary scattered light is generated from the liquid crystal panel 11, thereby increasing the brightness of black display and lowering the contrast. In addition, a second lens array 108 is provided near the input mask 12. The second lens array 108 functions as a field lens (hereinafter, the second lens array is referred to as a field lens array), and the image of each lens of the fly-eye lens 109 by the field lens array 108 is displayed on the liquid crystal panel 1.
1 to be formed on. Other configurations are the same as those of the first embodiment of the present invention shown in FIG. The liquid crystal panel 11 as a light valve uses the polymer dispersed liquid crystal panel used in the first embodiment or the diffraction grating polymer dispersed liquid crystal panel used in the second embodiment. Light rays emitted from the light source 15 are converted into a plurality of light source images by the fly-eye lens 109, and are formed at openings of the input mask 12. This light source image is further added to the field lens array 10.
8 illuminates the liquid crystal panel 11. LCD panel 11
Is off (scattered state), the light rays from each light source image are scattered by the liquid crystal panel 11, are blocked by the light shielding portion of the output mask 13, and do not reach the screen 17. On the other hand, when the liquid crystal panel 11 is turned on (transparent state), the light from each light source image passes through the liquid crystal panel 11 and passes through the opening corresponding to each of the output masks 13. The light beam reaches the screen 17 with little loss. At this time, the effective F-number of the projection lens is determined by the total area of the openings of the output mask 13, and is larger than the F-number of the projection lens when the output mask 13 is not used, so that the contrast can be further increased.

FIG. 13 shows a plan view of the fly-eye lens 109. The fly-eye lens 109 has a plurality of lenses 1
10 and each lens 110 is configured to correspond to the opening 31 of the input mask 12 (FIG. 3). It is desirable that the opening shape of each lens 110 be similar to the effective display area of the liquid crystal panel 11.
That is, if the effective display area of the liquid crystal panel 11 is rectangular and the aspect ratio is, for example, 3: 4, the lens 110 is also 3: 4.
Rectangle with the aspect ratio of Field lens array 10
8 is designed so that the image of each lens 110 is formed on the liquid crystal panel 11. As a result, light emitted from the light source 15 passing through one lens 110 passes through one opening of the input mask 12, passes through the field lens array 108, the schlieren lens 14, the liquid crystal panel 11, and the output mask 13.
Through the projection lens 16. If this optical path is considered as one optical system, the F-number is large and the contrast can be high, and the optical path can be regarded as one system in which many optical systems are gathered, so that the brightness is not reduced. In other words, when the liquid crystal panel 11 is in the transparent state by the output mask 13, the entire effective portion of the pupil is used. When the liquid crystal panel 11 is in the scattered or diffracted state, unnecessary scattered or diffracted light can be shielded, and the pupil area can be effectively reduced. .

Hereinafter, the light valve type projection device of the present invention will be described with reference to the drawings. (FIG. 14) is a configuration diagram of an embodiment of the light valve type projection device of the present invention. However, components unnecessary for the description are omitted.
In FIG. 14, reference numeral 121 denotes a condensing optical system, which has a concave mirror and a 250 W metal halide lamp as light generating means inside. The concave mirror is configured to reflect only visible light. Further, the condensing optical system 12
An ultraviolet cut filter is arranged at the exit end of the first light emitting element. Reference numeral 122 denotes an infrared cut mirror that transmits infrared light and reflects only visible light. However, it goes without saying that the infrared cut mirror 122 may be arranged inside the light collecting optical system 121. Also, 123a is a BDM, 123a
b is GDM and 123c is RDM. In addition, BDM1
The arrangement of the RDMs 23a to 23c is not limited to the above-described order, and it goes without saying that the last RDM 123c may be replaced with a total reflection mirror.

Reference numerals 127a, 127b and 127c are liquid crystal panels. The height d of the diffraction grating formed in the liquid crystal panel 127c that modulates the R light among the liquid crystal panels is 0.2 μm or more larger than the height d of the diffraction gratings of the other liquid crystal panels.
It is formed 1.0 μm higher. This is because the degree of diffraction depends on the wavelength of the light to be modulated. If necessary, the height of the diffraction grating of the liquid crystal panel 127a for blue light modulation is formed to be 0.2 μm to 1.0 μm lower than that of the liquid crystal panel 127a for green light.
The liquid crystal panel 127c that modulates the R light has a larger droplet-shaped liquid crystal particle diameter or a larger liquid crystal film thickness than other liquid crystal panels. This is because the scattering characteristic decreases as the light becomes longer in wavelength. The particle size of the water-droplet liquid crystal can be controlled by controlling ultraviolet light at the time of polymerization or by changing the material used.
The liquid crystal film thickness can be adjusted by changing the diameter of the beads in the liquid crystal layer. 125a, 125b and 125c are input masks, 128a, 128b and 128c are output masks,
126a, 126b and 126c are schlieren lenses. Note that 124a, 124b and 124c are fly-eye lenses, 129a, 129b and 129c
Is a projection lens.

Fly-eye lens 124 and input mask 1
25 may be collectively installed as one between the condensing optical system 121 and the dichroic mirror 123a. Further, the schlieren lens 126 includes the liquid crystal panel 127 and the output mask 12.
8 may be installed.

In the light valve type projection apparatus of the present invention, when the thickness of the liquid crystal layer of the liquid crystal panel is 10 μm to 15 μm, the contrast ratio is about 6 degrees at full angle, and the contrast ratio is at the center of the screen. The ratio was 100: 1 or more, and when projected on a 40-inch screen by a rear television, an image quality comparable to that of a CRT projection television could be obtained. The lamp was a 250 W metal halide lamp having an arc length of 7 mm, and sufficient characteristics were obtained without using a short arc lamp. The configuration diagram of FIG. 14 is more specifically shown as an example in a perspective view of FIG. 15. (Figure 1
In 5), 133 is a mirror, and 134a, 134b and 134c are projection lenses or projection lens systems. The fly-eye lens 124 and the input mask 125 are installed at the exit end of the light-collecting optical system 121.

The operation of the light valve type projection apparatus according to the present invention will be described below with reference to FIG. Since the respective modulation systems for red (R), green (G), and blue (B) light have almost the same operation, the modulation system for B light will be described as an example. First, white light is emitted from the condensing optical system 121, and the B light component of the white light is BDM1.
23a. The B light is a fly-eye lens 124a, an input mask 125a, a schlieren lens 1
The light enters the polymer-dispersed liquid crystal panel 127a through 26a. As shown in FIGS. 21A and 21B, the polymer-dispersed liquid crystal panel modulates light by controlling the scattering and transmission state of incident light by a signal applied to the pixel electrode. The scattered light is shielded by the output mask 128a, and conversely, parallel light or light within a predetermined angle passes through the output mask 128a. The modulated light is enlarged and projected on a screen (not shown) by the projection lens 129a. As described above, the B light component of the image is displayed on the screen. Similarly, the polymer dispersed liquid crystal panel 127b modulates the light of the G light component, and the polymer dispersed liquid crystal panel 127c modulates the light of the R light component, so that a color image is displayed on the screen.

The configuration of the liquid crystal panel of the present invention is a TFT.
The present invention is not limited to this, and is also effective for a liquid crystal display device using a two-terminal element such as a diode as a switching element.

Further, in FIG. 14, the light is made to enter from the opposite substrate side of the liquid crystal panel. However, the present invention is not limited to this, and it is apparent that the same effect can be obtained by making it enter from the array substrate. It is. As described above, the light valve type projection device of the present invention does not depend on the incident direction of light.

Further, in the embodiment of the light valve type projection device of the present invention, the expression is described as a rear type projection device.
It is needless to say that the present invention is not limited to this, and may be a front projection device that projects an image on a reflection screen. Further, in the light valve type projection device of the present embodiment, the color separation is performed by the dichroic mirror, but the present invention is not limited to this. For example, the color separation may be performed by using an absorption type color filter.

The liquid crystal panel used in the present invention has been described as a transmissive liquid crystal panel, but is not limited to this, and may be a reflective liquid crystal panel. In that case, the pixel electrode may be a reflective electrode made of a metal material. The diffraction grating is formed on the counter electrode or the reflection electrode.

Further, in the light valve type projection apparatus of this embodiment, one projection lens system is provided for each of the R, G, and B light modulation systems. However, the present invention is not limited to this. Needless to say, the display image modulated by the liquid crystal panel may be combined into one, and then may be incident on one projection lens system and projected. Further, a liquid crystal panel for modulating each of R, G, and B lights is provided, but the present invention is not limited to this. For example, a single-panel projection device that attaches a mosaic color filter to one liquid crystal panel and projects pixels of the panel may be used.

[0066]

As described above, in the light valve type projection apparatus of the present invention, since the polymer dispersed liquid crystal is used as the liquid crystal panel, a high brightness screen is twice or more as compared with the liquid crystal panel using the TN liquid crystal. Can be obtained. Further, a diffraction grating is formed in the liquid crystal panel, and when the liquid crystal is in the ON state, there is almost no difference in the refractive index from the liquid crystal layer 23, so that no diffraction grating is formed. Therefore, the light incident on the liquid crystal panel goes straight without being diffracted. Conversely, when the liquid crystal is off, a difference in refractive index occurs between the liquid crystal layer 23 and the diffraction grating, and the diffraction grating functions. Therefore, light incident on the liquid crystal panel is diffracted. This means that the amount of light traveling straight is reduced. The contrast of the projected image is greatly improved by the synergistic effect of the above-described diffraction effect and scattering effect. Further, according to the present invention, a triangular-wave cross-sectional shape layer is formed in the liquid crystal panel, and when the liquid crystal is on, there is almost no difference in refractive index from the liquid crystal layer 23. Therefore, the light incident on the liquid crystal panel goes straight without refraction. Conversely, when the liquid crystal is in the off state, a difference in refractive index occurs between the liquid crystal layer 23 and the triangular-wave cross-section layer, and light incident on the liquid crystal panel is refracted. This means that the amount of light traveling straight is reduced. The contrast of the projected image is greatly improved by the synergistic effect of the refraction effect and the scattering effect described above. Moreover, the liquid crystal panel can be driven at a low voltage.

Further, it is possible to provide a projection apparatus which can realize a high contrast ratio and a high brightness even when a bright light source having a long arc length, a small F number and a light source is used as the light source.

Further, in the present invention, the contrast ratio of the whole image is greatly increased by changing the height of the diffraction grating, the thickness of the liquid crystal layer or the diameter of the liquid crystal in the liquid crystal panel, mainly for the R liquid crystal panel, from those of other panels. Can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram conceptually showing a principle configuration of a light valve type projection apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a liquid crystal panel used as a light valve in the first embodiment of the present invention.

FIG. 3 is a schematic plan view of an input mask and an output mask used in the present invention.

FIG. 4 is a schematic diagram showing a distribution state of light intensity on an output mask by a liquid crystal panel in the light valve type projection apparatus according to the first embodiment of the present invention.

FIG. 5 is a plan view and a sectional view of a liquid crystal panel used as a light valve in a second embodiment of the present invention.

FIG. 6 is a sectional view of a liquid crystal panel used as a light valve in a second embodiment of the present invention.

FIG. 7 is a schematic diagram showing a distribution state of light intensity on an output mask of a light beam modulated by a liquid crystal panel in a second embodiment of the present invention.

FIG. 8 is a plan view and a sectional view of a liquid crystal panel used as a light valve in a second embodiment of the present invention.

FIG. 9 is a sectional view of a liquid crystal panel used as a light valve in a second embodiment of the present invention.

FIG. 10 is a sectional view of a liquid crystal panel used as a light valve in a third embodiment of the present invention.

FIG. 11 is a schematic diagram showing a distribution state of light intensity on an output mask of a light beam modulated by a liquid crystal panel in a third embodiment of the present invention.

FIG. 12 is a schematic diagram conceptually showing a principle configuration of a light valve type projection device according to a fourth embodiment of the present invention.

FIG. 13 is a plan view of a fly-eye lens used in a fourth embodiment of the present invention.

FIG. 14 is a configuration diagram of one embodiment of a light valve type projection device of the present invention.

FIG. 15 is a configuration diagram of another embodiment of the light valve type projection device of the present invention.

FIG. 16 is a configuration diagram of a conventional liquid crystal projection device.

FIG. 17 is a plan view of a conventional liquid crystal panel.

FIG. 18 is a plan view and a sectional view of a conventional liquid crystal panel.

FIG. 19 is a cross-sectional view of a conventional liquid crystal panel.

FIG. 20 is an explanatory diagram of the operation of the TN liquid crystal panel.

FIG. 21 is an explanatory diagram of the operation of the polymer dispersed liquid crystal panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Light valve (liquid crystal panel) 12 Input mask 13 Output mask 14 Schlieren lens 15 Light source 16 Projection lens array substrate 17 Screen 18 Concave mirror 21 Opposite substrate 22 Opposite electrode 23 Polymer dispersed liquid crystal layer 24 Pixel electrode 25 TFT 26 Array substrate 27 Black matrix 53 Irregular cross section layer (diffraction grating) 81 Triangular wave cross section layer 108 Field lens array 109 Fly eye lens 122 Infrared cut mirror 123a, 123b, 123c Dichroic mirror

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G03B 33/12 G03B 21/00

Claims (11)

(57) [Claims] A light valve configured to modulate light generated by the light generating means as a change in a scattering state;
Projection means for projecting light modulated by the light valve; a first mask disposed between the light generation means and the light valve; and a first mask disposed between the projection means and the light valve comprising a second mask that is, an imaging means disposed between said first mask and said second mask, before
A light valve type projection apparatus, wherein a projection image of the opening of the first mask by the imaging means coincides with the opening of the second mask. 2. A light generating means, a light valve for modulating light generated by the light generating means as a change in a diffraction state,
Projection means for projecting light modulated by the light valve; a first mask disposed between the light generation means and the light valve; and a first mask disposed between the projection means and the light valve comprising a second mask that is, an imaging means disposed between said first mask and said second mask, before
A light valve type projection apparatus, wherein a projection image of the opening of the first mask by the imaging means coincides with the opening of the second mask. 3. A light generating means, a light valve for modulating the light generated by the light generating means as a change in scattering or diffraction state, and a projecting means for projecting the light modulated by the light valve, A first mask disposed between the light generating means and the light valve, a second mask disposed between the projection means and the light valve, the first mask and the second mask; comprising an imaging means which is disposed between the mask and a lens array comprising a plurality of lenses for forming an image of said light generating means in the opening of the first mask, said imaging means
Wherein the projected image of the opening of the first mask according to ( b) coincides with the opening of the second mask. 4. The light valve type projection device according to claim 3, wherein the lens array comprises a plurality of lenses having a similar shape to the effective display area of the light valve. 5. A light valve, comprising: a light valve that modulates light generated by the light generator as a change in scattering or diffraction state; and a projecting unit that projects light modulated by the light valve. A first mask disposed between the light generating means and the light valve, a second mask disposed between the projection means and the light valve, the first mask and the second mask; Image forming means arranged between masks, a lens array including a plurality of lenses for forming an image of the light generating means in an opening of the first mask, and a lens array arranged near the first mask; comprising a second lens array which forms an image of the first lens array on the light valve, before
A light valve type projection apparatus, wherein a projection image of the opening of the first mask by the imaging means coincides with the opening of the second mask. 6. The light valve according to claim 1, wherein the projection means is a projection lens system, and the second mask is arranged near a pupil of the projection lens system. Projection device. 7. A polymer dispersed liquid crystal in which a liquid crystal material is dispersed and held in a polymer matrix between a first and a second substrate on which at least one of which has an electrode layer has a light transmitting property. The light valve type projection device according to claim 1, wherein the projection device is a liquid crystal panel that holds the light valve. 8. A light-valve comprising a polymer-dispersed liquid crystal in which a liquid crystal material is dispersed and held in a polymer matrix between first and second substrates, at least one of which has an electrode layer and has a light-transmitting property. And a refractive index of the polymer-dispersed liquid crystal layer when the liquid crystal panel is in a light transmitting state on a surface of at least one of the first and second substrates facing the polymer-dispersed liquid crystal layer. 6. The light valve type projection device according to claim 2, wherein the liquid crystal panel is a liquid crystal panel on which an uneven cross-sectional shape layer made of a light transmissive substance substantially conforming to the above is formed. 9. A light-valve comprising a polymer-dispersed liquid crystal in which a liquid crystal material is dispersed and held in a polymer matrix between a first and a second substrate on which at least one of the electrode layers is formed and has a light-transmitting property. And a refractive index of the polymer-dispersed liquid crystal layer when the liquid crystal panel is in a light transmitting state on a surface of at least one of the first and second substrates facing the polymer-dispersed liquid crystal layer. 6. The light valve type projection device according to claim 2, wherein the liquid crystal panel is a liquid crystal panel having a triangular wave or saw-tooth cross-sectional shape layer made of a light transmissive substance substantially corresponding to the above. 10. A color separation means for separating light rays generated from the light generation means into light of a predetermined range of wavelengths, wherein at least one of the polymer dispersed liquid crystal panels arranged for each wavelength of light is provided. At least one of the thickness of the polymer dispersed liquid crystal layer and the average particle diameter or average pore diameter of the liquid crystal droplets, and the height and pitch of the unevenness of the uneven cross-sectional shape layer formed in the polymer dispersed liquid crystal panel are other polymer dispersed. 9. The light valve type projection device according to claim 7, wherein the projection device is different from a liquid crystal panel. 11. A liquid crystal display, comprising: a light source; a polymer dispersed liquid crystal panel; and a projection lens for projecting light modulated by the polymer dispersed liquid crystal panel, and a light source disposed between the light source and the liquid crystal panel. An image of the light source in an opening of the first mask, a first lens array including a plurality of lenses similar in shape to an effective display area of the liquid crystal panel, and a first lens array;
A second lens array that is arranged near the mask and forms an image of the first lens array on the liquid crystal panel; a second mask that is arranged between the projection lens and the liquid crystal panel; An imaging lens disposed between the first mask and the second mask, wherein a projection image of the opening of the first mask by the imaging lens is formed on the second mask. And a light valve type projection device, wherein the projection coincides with the opening of the second mask.