JPH1115023A - Reflection type liquid crystal display device and projection type display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently reduce heat absorption energy in a liquid crystal display device by high-output irradiation light in a projection type display device mainly using a reflection type liquid crystal display device using a polymer dispersed liquid crystal as a light valve. Dissipate heat. SOLUTION: A cooling device 1B including a Peltier element pair group 54, a heat radiating plate 12, a heat radiating fin 11, and a small cooler 1C is brought into close contact with a reflection plate 13 having an endothermic effect in a liquid crystal display device 1Z.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type liquid crystal display device for controlling the temperature of a liquid crystal panel and maintaining display performance, and a projection type display device using the liquid crystal display device as a light valve.

[0002]

2. Description of the Related Art A liquid crystal display device has many features such as a light weight and a thin shape as compared with a CRT, and therefore has been actively researched and developed. Recently, it has been used as a pocket television, a personal computer display, or a vehicle television.
However, there are many problems such as difficulty in increasing the screen. Therefore, in recent years, a projection-type display device that obtains a large-screen display image by enlarging and projecting a display image of a small-sized liquid crystal display device with a projection lens or the like has attracted attention. At present, a commercially available projection type display device uses a twisted nematic (hereinafter abbreviated as TN) type liquid crystal display device utilizing the optical rotation characteristics of liquid crystal.

A transmission type liquid crystal display device using a TN liquid crystal is
It is necessary to convert incident light into linearly polarized light using a polarizing plate (polarizer). Also, a polarizing plate (analyzer) needs to be arranged on the emission side of the liquid crystal display device in order to detect light modulated by the liquid crystal display device. That is, it is necessary to arrange two polarizing plates on both sides of the TN liquid crystal display device, a polarizer for converting light into linearly polarized light and an analyzer for detecting modulated light.

In this case, the pixel aperture ratio of the liquid crystal display device is set to 1
Assuming that the amount of light incident on the polarizer is 100%,
Since the amount of light emitted from the polarizer is 40%, the transmittance of the liquid crystal display device is 80%, and the transmittance of the analyzer is 80%, the overall transmittance is 0.4 × 0.8 × 0.8 = It is about 25%, and only 25% of the light can be used effectively. Therefore, only a low-luminance image display can be realized with the TN liquid crystal display device.

Most of the light lost by the polarizing plate is absorbed by the polarizing plate and converted into heat. This heat is applied to the liquid crystal display device from the polarizing plate itself and by radiation or the like, thereby heating the liquid crystal display device. In the case of the projection display device, the amount of light incident on the polarizing plate is tens of thousands lux or more. Therefore, when a TN liquid crystal display device is used as a light valve of a projection type display device, the polarizing plate, the panel, and the like are brought to a high temperature state, causing significant performance degradation in a short period of time.

In a TN liquid crystal display device, it is necessary to apply an alignment film and perform a rubbing process. This rubbing treatment or the like increases the number of steps and causes an increase in manufacturing cost. Further, in recent years, the number of pixels of a liquid crystal display device used for a projection type display device has a large capacity of 300,000 pixels or more, and the pixel size tends to be miniaturized. Pixel miniaturization is signal line, TFT
Many irregularities are formed per unit area due to the above. Therefore, it is clear that the rubbing treatment cannot be performed properly due to the unevenness. In addition, miniaturization of the pixel size increases the formation area of the TFT and the signal line occupying one pixel, and reduces the pixel aperture ratio. The reduction of the pixel aperture ratio is not limited to lowering the brightness of the display image, but the liquid crystal display device is further heated by light irradiated to the portion other than the incident light aperture, thereby accelerating the performance deterioration of the TN liquid crystal display device. I do.

The TN liquid crystal modulates the light by changing the alignment state of the liquid crystal by a voltage applied to the pixel electrode. Polarizing plates are arranged on the entrance side and the exit side of the TN liquid crystal display device, respectively, and the polarization axes of the polarizer and the analyzer are orthogonal to each other. Generally, a TN liquid crystal display device is used in a mode (normally white (NW) mode) in which black display can be performed with a voltage applied.

Although the display image of the NW mode liquid crystal display device has good color reproducibility, there is a problem of light leakage from the periphery of the pixel as a problem. This is because the liquid crystal molecules are not aligned in the normal direction but are aligned in the opposite direction. This alignment state is called an inverted chilled domain. This is because the rising direction of the liquid crystal molecules is changed by the electric field generated between the pixel electrode and the source signal line.
It arises from partial reversal. In the part where the rising direction of the liquid crystal molecules is reversed, the light passes through the analyzer on the light emitting surface of the panel despite the application of the voltage. That is, light leakage occurs. No light leakage occurs in the normal liquid crystal rising direction.

As a method of preventing light leakage, there is a method of increasing the width of a black matrix (BM) formed on a counter electrode. However, this also reduces a pixel closed area and lowers display brightness. It is not an effective method.

In the TN liquid crystal, a polarizing plate is used before the liquid crystal display device. However, when a polymer dispersed (PD) liquid crystal is used,
The liquid crystal display device can be configured without considering the heat generated by the polarizing plate. This polymer dispersion without using a polarizing plate (P
D) A projection display device using a liquid crystal display device has already been disclosed. A PD liquid crystal display device as a light valve used in a projection display device performs light modulation by scattering or transmitting incident light.

The operation of the PD liquid crystal display device will be briefly described with reference to FIG. FIG. 2 is an explanatory diagram of the operation of the PD liquid crystal display device. In FIG. 2, a liquid crystal in the form of water droplets (hereinafter, referred to as a water-drop liquid crystal 22) is dispersed in a polymer 21. A TFT (not shown) or the like is connected to the pixel electrode 15, and a voltage is applied to the pixel electrode 15 when the TFT is turned on and off, and the direction of liquid crystal alignment on the pixel electrode 15 is changed to modulate light. As shown in FIG. 2A, when no voltage is applied, the liquid crystal molecules 23 in each of the droplet liquid crystals 22 are oriented in an irregular direction. In this state, the polymer (resin component) 21 and the water-drop liquid crystal (liquid crystal component 22)
And a difference in refractive index occurs, and the incident light is scattered.

Here, as shown in FIG. 2B, when a voltage is applied to the pixel electrode 15, the directions of the liquid crystal molecules 23 are aligned.
If the refractive index when the liquid crystal molecules 23 are aligned in a certain direction is adjusted in advance to the refractive index of the polymer 21, incident light is emitted from the array substrate 14 (or the counter substrate 1A) without being scattered.

Alternatively, in the liquid crystal display device, a source drive circuit, a gate drive circuit, and a liquid crystal display section can be formed on the same glass substrate by using a low-temperature polysilicon technique. Therefore, it will be used for various applications in the future as a liquid crystal module including a drive circuit.

[0014]

A transmission type liquid crystal display device using a TN liquid crystal requires a polarizing plate in a panel, or light leakage is likely to occur around a pixel.
Must be thicker. Therefore, the light utilization efficiency is low, and the unused light is converted into heat. The light applied to the BM heats the liquid crystal display device, increasing the panel temperature and shortening the life of the panel. To do this, a polymer-dispersed liquid crystal (PD) using natural light without using polarized light
Liquid crystal).

However, there is a problem in the PD liquid crystal display device. That is, the display contrast is low. As shown in FIG. 2, when the liquid crystal layer 18 is in the scattering state, black display is performed.
White display is made in the transparent state. Therefore, the contrast cannot be increased unless the scattering state is sufficiently increased.

On the other hand, in the reflection type liquid crystal display device shown in FIG. 1, since a linearly polarized light to be used is obtained by a polarizing plate (polarizer) or a polarization beam splitter in the illumination light path, a transmission type liquid crystal display device using TN liquid crystal is used. The amount of heat absorbed by the polarizer or analyzer can be reduced. When a polymer-dispersed liquid crystal is used, heat absorption by a polarizing plate is eliminated, but heat absorbed by a BM, a reflection plate, or the like is always generated.

The present invention has been made in view of the above circumstances, and a reflective liquid crystal display device capable of efficiently radiating heat caused by incident light and maintaining characteristics for a long period of time, and a projection using the same. It is an object to provide a type display device.

[0018]

Means for Solving the Problems In order to solve the above problems, the present invention has taken the following means. According to the first aspect of the present invention, a first electrode substrate, a second electrode substrate including a reflective electrode having a light reflecting function and a heat absorbing function, and a narrow space between the first electrode substrate and the second electrode substrate. A liquid crystal layer that forms an optical image as a change in the held light scattering state, and a heat radiating unit that is provided directly on the reflective electrode and radiates heat absorbed by the reflective electrode are adopted.

According to a second aspect of the present invention, there is provided a first electrode substrate having a counter electrode formed thereon, and a second electrode substrate having pixels formed in a matrix and having a light reflecting function and a heat absorbing function. A polymer-dispersed liquid crystal layer sandwiched between the first electrode substrate and the second electrode substrate, and a heat radiating unit provided directly on the reflective electrode and radiating heat absorbed by the reflective electrode, Is adopted.

According to these configurations, since the reflective electrode has a heat absorbing function, heat caused by light reaching the reflective electrode can be efficiently absorbed by the reflective electrode. Thus, the absorbed heat can be effectively released to the outside by the heat radiating means provided directly on the reflection electrode. As a result, heat can be effectively radiated from the liquid crystal panel.

According to the second aspect of the present invention, since a polymer-dispersed liquid crystal is used for the liquid crystal layer, no polarizer or the like is required, and the temperature rise of the liquid crystal panel can be further suppressed.

According to the second aspect of the present invention, the ratio of the liquid crystal material in the polymer-dispersed liquid crystal is 60 to 90%, and the ordinary light refraction no of the liquid crystal material is 1.50 to 1.53.
And the refractive index difference n is preferably from 0.15 to 0.30.

In the invention according to any one of claims 1 to 3, the ratio between the liquid crystal layer and the first electrode substrate and between the liquid crystal layer and the second electrode substrate is smaller than that of the liquid crystal layer. It is preferable that a film having high resistance be provided.

According to a fifth aspect of the present invention, there is provided a first electrode substrate on which a counter electrode is formed, pixel electrodes arranged in a matrix, a switching element for switching the pixel electrodes, and a reflection film having a heat absorbing function. A transparent substrate having an optical coupling layer on one surface on the side of the first electrode substrate and an antireflection film on the other surface; A liquid crystal layer sandwiched between the first and second electrode substrates, and at least one of between the switching element and the first electrode substrate and between the switching element and the reflective film, and light enters the switching element. A light-shielding film for preventing, and provided directly on the reflection film,
And a heat radiating means for radiating the heat absorbed by the reflection film.

According to a sixth aspect of the present invention, there is provided a first electrode substrate on which pixel electrodes arranged in a matrix and a switching element for switching the pixel electrodes are formed;
A second electrode substrate including a counter electrode and a reflective film having a heat absorbing function, a transparent substrate having an optical coupling layer on one surface on the first electrode substrate side, and having an antireflection film on the other surface,
A liquid crystal layer sandwiched between the first electrode substrate and the second electrode substrate; and at least one between the switching element and the first electrode substrate and between the switching element and the reflective film. A light shielding film for preventing light from entering the switching element, and a heat radiating means provided directly on the reflection film and radiating heat absorbed by the reflection film.

According to these configurations, since the reflection film has a heat absorbing function, the heat caused by the light reaching the reflection film can be efficiently absorbed by the reflection film. Thus, the absorbed heat can be effectively released to the outside by the heat radiating means provided directly on the reflection film. As a result, heat can be effectively radiated from the liquid crystal panel.

According to a fifth or sixth aspect of the present invention, an insulating film having a higher specific resistance than the specific resistance of the liquid crystal layer is formed on the surface of the counter electrode in contact with the liquid crystal layer. Preferably, the reflection film is a dielectric reflection film composed of a multilayer dielectric thin film.

In the invention according to any one of claims 1 to 8, it is preferable that a film thickness holding means is provided between the first electrode substrate and the second electrode substrate. The holding means is preferably a bead of a material having a high thermal conductivity.

According to an eleventh aspect of the present invention, in any one of the first to tenth aspects, the heat radiating means has a configuration including a cooling fan, a Peltier element group, and a heat radiating plate.

According to this configuration, the heat radiation of the Peltier device group can be sufficiently exhibited. Further, since the Peltier element is provided directly on the reflection electrode or the reflection film, the temperature can be controlled freely. For example, the liquid crystal panel can be heated by reversing the direction (for cooling) of the current flowing through the Peltier element, thereby reducing the viscosity of the highly viscous liquid crystal material and increasing the response of the liquid crystal material. Can be. That is, the temperature control effect of the Peltier element can be efficiently exerted on the liquid crystal material, and the response of the display device can be controlled.

According to a twelfth aspect of the present invention, in any one of the first to eleventh aspects, at least one of the first electrode substrate and the second electrode substrate includes a transparent substrate, a concave lens, or the like. A configuration in which an optical element is attached is adopted.

According to this configuration, it is possible to prevent the generation of the secondary scattered light in which the light scattered in the liquid crystal layer returns to the liquid crystal layer and is scattered again.

According to a thirteenth aspect of the present invention, there is provided a light generating means, and the light emitted by the light generating means is provided with a first light path for red light, a second light path for green light, and a third light path for blue light. A light separating means for separating light into the first light path;
The first reflective polymer dispersed liquid crystal display device according to claim 2, wherein the first reflective polymer dispersed liquid crystal display device modulates light in the second optical path. 3. The third reflective polymer dispersed liquid crystal display device according to claim 2, which modulates light in a third optical path, and an optical path that combines at least two optical paths among the first to third optical paths into one. And a projecting unit for projecting light modulated by the polymer-dispersed liquid crystal display device. Any one of the first to third polymer-dispersed liquid crystal display devices may include an optical path combining device and an optical path combining device. The optical path combining means is connected via a physical coupling layer, and a light absorbing means is arranged in a region where light effective for display does not pass.

According to this configuration, the heat caused by the incident light can be efficiently dissipated, so that even if a very large amount of light of tens of thousands lux is incident, the performance can be maintained for a long time. it can.

In the invention according to claim 13, the combining means is preferably a prism-shaped mirror.

According to the fifteenth aspect of the present invention, a light generating means having a luminous body, the reflection type liquid crystal display device of the second aspect, and the light emitted from the luminous body are condensed and converged. Secondary luminous body forming means for forming a secondary luminous body, projecting means for projecting an optical image formed by the light modulating means, first aperture means arranged on the light incident side of the light modulating means, A second diaphragm disposed on a light emission side of the light modulator, wherein the light modulator is illuminated by light emitted from the secondary light emitter, and the first diaphragm and the second diaphragm are illuminated by light emitted by the secondary light emitter. Is substantially conjugated with the aperture means, and the first aperture means has an opening shape for selectively passing light mainly passing through the effective area of the secondary luminous body, and the second aperture means Means that the first stop is in a state where the light modulation layer of the light modulation means is in a light transmitting state. A configuration having an opening shape that allowed to selectively pass the light which has passed through.

According to this configuration, the heat caused by the incident light can be efficiently radiated, so that even if a very large amount of light of tens of thousands of lux is incident, the performance can be maintained for a long period of time. it can. Further, according to this configuration, the display contrast can be increased while suppressing the light loss and maintaining the high luminance display.

According to the present invention, the first electrode substrate and the second electrode substrate of the reflection type liquid crystal display device are provided.
It is preferable that a film thickness holding means is provided between the substrate and the electrode substrate.

According to the fifteenth aspect of the present invention, the first
Is preferably disposed near the secondary illuminant. The secondary illuminant forming means forms a plurality of discrete illuminants which are discretely located, and the first aperture means and the second aperture Preferably, at least one of the means has a plurality of discretely located openings.

In the invention according to any one of the thirteenth to eighteenth aspects, the F-number of the projection means is approximately 5 to 5.
9 is preferable. Further, in the invention according to any one of claims 13 to 19, when the effective diagonal length of the liquid crystal display device is d (inch) and the arc length of the lamp of the light generating means is a (mm), It is preferable to satisfy the relationship of a (mm) ≦ d (inch).

[0041]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. According to the present invention, for example, in order to solve the problem of performance deterioration of a liquid crystal panel due to heat in a reflection type liquid crystal display device, a reflection film or a reflection electrode (reflection plate) having a heat absorption function is formed with a p-type semiconductor and n.
As shown in FIG. 5, a large number of Peltier electron pairs in which mold semiconductors are combined are arranged in series to constitute a heat pumping mechanism for discharging heat generated by the reflection film or the reflection electrode.
Further, in order to efficiently dissipate the discharged heat, the radiating fins and the small cooler are arranged as shown in FIG. Furthermore,
In order to prevent unnecessary reflected light, an anti-reflection film is formed or arranged on the incident surface of the display device.

As described above, in the reflection type liquid crystal display device of the present invention, the reflection film or the reflection electrode in the liquid crystal panel has a heat absorbing function, and the liquid crystal panel is provided with a member having a heat radiating function. Therefore, this is different from a configuration in which a cooling device having a heat absorbing function and a heat radiating function is simply attached to a liquid crystal panel.

In the case of a reflection type liquid crystal display device, the incident light is 2
Times through the liquid crystal layer (at the time of incidence: counter electrode (or pixel electrode) →
Reflective surface, when emitting: reflective surface → counter electrode (or pixel electrode)
I do. Therefore, the liquid crystal display device has the same effect as doubling the apparent liquid crystal film thickness, and can improve the display contrast. The electrodes are formed of a transparent material such as ITO, and the reflecting surface is a dielectric mirror formed by laminating a dielectric thin film.

Therefore, if a polarizing plate is used, the display contrast can be drastically improved. In the projection display device of the present invention, utilizing this property, the light from the light-emitting lamp is converted into P-polarized light or S-polarized light, and the polarized light is incident on the liquid crystal display device of the present invention. The display contrast can be improved by disposing a polarizing plate on the light emitting surface of the liquid crystal display device. The light modulated by the liquid crystal display device is magnified and projected on a screen by a projection lens. The method using this polarizing plate is a viewfinder, a direct-view monitor,
It can be applied to other display devices such as a liquid crystal television.

In the projection display device of the present invention, the liquid crystal display device of the present invention is used as a light valve. In addition, one in which three display areas are formed on one substrate 12 is used.
Further, a liquid crystal display device is optically coupled to the prism, and a light absorbing film is formed in an invalid area of the prism.

When the liquid crystal has a positive dielectric constant, the long axis direction of the liquid crystal molecules is an extraordinary light refractive index ne and the short axis direction is an ordinary light refractive index no.
It is. Therefore, when the liquid crystal molecules are aligned with the substrate 12 on average, the refractive index (theoretically, (no + ne) / 2) as viewed from the direction perpendicular to the substrate 12 becomes highest.

In the case of a polymer-dispersed liquid crystal display device, the higher the difference between the refractive index of liquid crystal molecules and the refractive index of a polymer, the better the scattering characteristics. However, in the case of the polymer-dispersed liquid crystal, the liquid crystal molecules are oriented in random directions when no voltage is applied to the liquid crystal layer. Therefore, the refractive index (theoretically, (2no + ne) / 3) as viewed from the direction perpendicular to the substrate 12 is lower than that in the case where the substrate 12 is oriented.

In the liquid crystal display device of the present invention, the opposing substrate 11
Alternatively, a wiring for generating a lateral electric field is formed on the array substrate 12 (or both in some cases), and lines of electric force are generated between the adjacent wirings. The liquid crystal molecules are aligned along the lines of electric force. Therefore, the difference in the refractive index between the polymer 24 and the liquid crystal increases. Therefore, display contrast can be improved.

When the liquid crystal display device is configured as a reflection type, the incident light passes through the liquid crystal layer twice, so that the scattering performance is enhanced and the display contrast can be improved. In order to increase the reflectivity and prevent heat absorption, the reflection surface is formed as a dielectric mirror having a dielectric multilayer structure. Further, an electrode is formed of ITO under the dielectric mirror. This is because the defective TFT is irradiated with laser light through the dielectric mirror to separate the TFT from the pixel. The present invention also enables the defect position to be observed with an infrared camera or the like. In this case, by using a metal material instead of ITO, all the laser light is absorbed by the metal material and the laser light does not reach the TFT.

The amorphous silicon type liquid crystal display device is a line sequential drive (a driving method for writing a signal to a pixel electrode for approximately one horizontal scanning period (1H period)), and has a sufficient writing time to a pixel. However, high-temperature polysilicon or low-temperature polysilicon type liquid crystal display devices (these types are collectively referred to as a polysilicon type or a polysilicon liquid crystal display device) are driven in a dot-sequential manner (the last pixel has a 1H block). This is a driving method in which there is only a time to write a signal to the pixel electrode during the ranking period), and it is difficult to secure a time to write a signal to the last pixel. Also,
If the writing time to the pixel is short, it is difficult to sufficiently charge the pixel with a signal, so that the liquid crystal on the pixel electrode is unlikely to be in a transparent state.

In order to solve this problem, the timing of the signal and the signal waveform width are controlled using a clock pulse in a driver circuit for applying a signal to the pixel. Thus, the input video signal can be reliably latched by the liquid crystal display device regardless of the variation in the electrical characteristics of the liquid crystal panel forming elements.

(Embodiment 1) FIG. 1 is a sectional view of a reflection type liquid crystal display device according to Embodiment 1 of the present invention. PD liquid crystal is used as a liquid crystal material. Note that not only the PD liquid crystal but also a combination of a polarizing plate and a TN liquid crystal may be used.

The array substrate 14 has pixel electrodes 15 made of ITO, source signal lines, gate signal lines (not shown),
A thin film transistor (hereinafter, referred to as a TFT) 17 and the like are formed. The drain terminal of the TFT 17 is connected to the pixel electrode 15 made of ITO. The pixel electrodes are arranged in a matrix, and are formed via an insulating film (not shown) so as not to be electrically connected to anything other than the drain terminal of the TFT 17. The insulating film is made of polyimide, SiO ₂ , S
It is formed of iNx or the like. The insulating film will be described later in detail. On the counter substrate 1A, a counter electrode 110 made of ITO or the like and a light-shielding film 19 on the incident side are arranged at positions where they cover the TFT 17 as viewed in parallel from the incident side.

As a heat radiating means, the heat absorbing side of the cooling module 1 B composed of the Peltier element pairs 45 is brought into close contact with the non-reflective surface of the reflecting plate 13. A radiation fin 11 and a small cooler 1C are attached to the radiation side of the cooling module 1B, so that heat pumped from the panel is radiated into the air.

The light-shielding films 16 and 19 are for preventing a photoconductor phenomenon from occurring due to the incident light or the light reflected by the reflection plate 13. Light shielding films 16 and 19
Is formed of Cr, Al, or the like, and has a thickness of 0.1 μm or more and 0.5 μm or less. Or 3 of Ti, Al, Cr, etc.
It may have a layer configuration.

The reflection plate 13 is obtained by attaching a dielectric reflection film of Al or the like to the heat-absorbing ceramic plate. It may be used instead of a ceramic plate as long as it has good thermal conductivity and the strength of a ceramic plate. The dielectric reflective film is formed by regularly stacking 20 or more high refractive index thin films and low refractive index thin films. This reflection plate 13 also has a heat absorbing function. Therefore, the reflector 13 only needs to be provided with the heat radiating means described above.

Although the pixel electrode 15 is made of ITO, it may be made of a polysilicon film. The thin polysilicon film is slightly brownish and has light transmittance. In particular, it is the same as the transparent state for an infrared wavelength. Therefore, it should be considered that the pixel electrode 15 is formed of a material having a light transmitting property with respect to light of any wavelength. Also,
An AIR coat film for preventing reflection may be formed on the interface between the counter substrate 1A and the air on the incident light side of the counter substrate 1A.

The TFT may be formed by any one of a low-temperature polysilicon technology, an amorphous silicon technology, a high-temperature polysilicon technology, and a single crystal technology formed on silicon ware. , A varicap, a thyristor, a MOS transistor, or the like. Here, it is assumed that the opposing substrate 1A and the array substrate 14 are glass substrates (Corning Co., Ltd. 7059), and the plate thickness is 1.1 mm.

The light-shielding film 19 on the incident side is connected to the counter electrode 110.
However, when the angle of view of the light incident on the panel is large, the reflected light from the reflector is blocked and the display light is darkened.
It may be arranged on the incident light side of the TFT 17. Where TF
If the reflection-side light-shielding film 16 and the incident-side light-shielding film 19 are concentrated around T17, heat is likely to be trapped in the TFT due to light absorption of the light-shielding film, leading to a malfunction of the TFT17.

When a PD liquid crystal is used, the display mode is a normally black mode (NB mode). That is, when a voltage is applied between the counter electrode 110 and the pixel electrode 15,
The pixel is in a transmissive state (white) and, when no voltage is applied, in a scattered state (black).

When the light that has entered the glass substrate 1A enters the voltage-applied pixel, it passes through the liquid crystal layer 18, is reflected by the pixel electrode with a reflector or a reflector, passes through the liquid crystal layer 18 again, and exits from the glass substrate 1A. And a white display is obtained. At this time, the transmittance increases as the electric field between the opposing electrode 110 and the pixel electrode 15 increases, and conversely, the scattering degree increases as the electric field decreases.

When the incident light is incident on the non-applied pixel, the light is scattered by the PD liquid crystal molecules, and the scattered light is not effectively reflected by the reflector, so that the pixel is displayed in black. It can be considered to be equivalent to twice the liquid crystal film thickness 18 as compared with a transmission type liquid crystal display device. Therefore, the display contrast can be improved.

A PD is provided between the counter electrode 110 and the pixel electrode 15.
The liquid crystal 18 is held. The liquid crystal material used for the liquid crystal display device 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 compounds.

Among the liquid crystal materials described in the line, a cyanobiphenyl nematic liquid crystal having a relatively large difference between the extraordinary refractive index ne and the ordinary refractive index no, or a fluorine-based or chloro-based nematic liquid crystal which is stable over time. Nematic liquid crystals are preferred,
Among them, chloro nematic liquid crystals are most preferable because they have good scattering properties and are hardly changed with time.

As the polymer matrix material, a transparent polymer is preferable. As the polymer, a photo-curing type resin is used in view of easiness of the production process, separation from the liquid crystal phase, and the like. 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. Above all, a photocurable acrylic resin having a fluorine group is preferable because the light modulating layer 18 having good scattering characteristics can be produced, and a change with time hardly occurs.

The liquid crystal material preferably has an ordinary light refractive index no of 1.49 to 1.54.
Above all, it is preferable to use one having an ordinary refractive index no of 1.50 to 1.53. Further, the refractive index difference Δn is 0.1
It is preferable to use one having a value of 5 or more and 0.30 or less.
When no and Δn increase, heat resistance and light resistance deteriorate. n
When o and Δn are small, the heat resistance and light resistance are improved, but the scattering characteristics are lowered and the display contrast is not sufficient.

As described above, as a constituent material of the light modulating layer 21, a chloro nematic liquid crystal having an ordinary refractive index no of 1.50 to 1.53 and Δn of 0.20 to 0.30 is used. It is preferable to use a photocurable acrylic resin having a fluorine group as the resin material.

Examples of such a polymer-forming monomer include:
2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, neopentyl glycol acrylate, hexanediol diacrylate, 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
-One ("Darocure 1116", manufactured by Merck), 1-bidroxycyclohexylphenyl ketone ("Irgacure 184", manufactured by Ciba-Gaiky), benzyl methyl ketal ("Irgacure 651," manufactured by Ciba-Geigy), and the like. In addition, a chain transfer agent, a photosensitizer, a dye, a cross-linking agent and the like can be appropriately used as optional components.

The refractive index n when the resin material is cured
p and the ordinary light refractive index no of the liquid crystal are made to substantially match.
When an electric field is applied to the liquid crystal layer, the liquid crystal molecules are aligned in one direction, and the refractive index of the liquid crystal layer becomes no. Therefore, the refractive index np of the resin coincides with that of the resin, and the liquid crystal layer is in a light transmitting state. If the difference between the refractive indices np and no is large, the liquid crystal layer will not be completely in a transparent state even when a voltage is applied to the liquid crystal layer, and the display brightness will be reduced. The difference between the refractive indexes np and no is preferably within 0.1, more preferably within 0.05.

The proportion of the liquid crystal material in the PD liquid crystal layer is not specified here, but is generally about 30 to 90% by weight, preferably about 60 to 90% by weight. When the content is less than 30% 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 scattering characteristics are reduced. The structure of the polymer-dispersed liquid crystal layer changes depending on the liquid crystal fraction. At about 50% by weight or less, the liquid crystal droplets exist as independent water droplets, and at 50% by weight or more, the polymer and the liquid crystal become continuous. Layer.

It is preferable that the average particle diameter of the water-droplet liquid crystal or the average pore diameter of the polymer network is 0.5 μm or more and 3.0 μm or less. Among them, 0.8μm or more and 2μ
m or less is preferable. When the light modulated by the PD liquid crystal display device has a short wavelength (for example, B light), it is small, and when it is long wavelength (for example, R light), it is large. If the average particle diameter of the liquid crystal droplets or the average pore diameter of the polymer network is large, the voltage required for the transmission state decreases, but the scattering characteristics deteriorate. When it is small, the scattering characteristics are improved, but the voltage required for the transmission state is high.

When a polymer dispersed liquid crystal is used in the liquid crystal display device of the present invention, the average particle size of the droplet liquid crystal or the average pore size of the polymer network of the liquid crystal display device that modulates blue light is changed by the liquid crystal that modulates red light. It is smaller than that of the display device. Alternatively, the liquid crystal layer 18 of the liquid crystal display device that modulates red light has a larger thickness than other liquid crystal display devices.

The polymer-dispersed liquid crystal according to the present invention is a liquid crystal in which the liquid crystal is dispersed in a resin in a water droplet form (see FIG. 2), the resin becomes a sponge form (polymer network), and the liquid crystal is filled between the sponge forms. And the like, and also includes a layered resin as disclosed in JP-A-6-208126, JP-A-6-202085, and JP-A-6-347818. I do. In addition, as described in Japanese Patent Publication No. 3-52843, a liquid crystal in which a liquid crystal is sealed in a capsule-shaped storage medium is also included. Further, a liquid crystal or a resin 21 containing a dichroic or polychromatic dye is also included. Alternatively, Japanese Patent Application Laid-Open No. 6-34776 discloses a similar configuration.
Some of them are disclosed in Japanese Patent Application Laid-open No. 5 and these are also included in the polymer dispersed liquid crystal of the present invention.

The thickness of the liquid crystal layer 18 is preferably in the range of 5 to 20 μm, more preferably 8 to 15 μm. If the film thickness is small, the scattering characteristics are poor and contrast cannot be obtained. Conversely, if the film thickness is large, high voltage driving must be performed. A gate drive circuit that generates a signal to turn on and off the TFT on the gate signal line, and a video signal on the source signal line It becomes difficult to design a source drive circuit for applying the voltage.

Further, as shown in FIG. 1, a light shielding film 16 is formed on the TFT 17. The light shielding films 16 and 19 mainly prevent light scattered by the liquid crystal layer 18 from being incident on the semiconductor layer of the TFT 17. When light enters the semiconductor layer, the TFT 17 does not turn off or the TFT 17 does not turn off.
A photoconductor phenomenon (hereinafter referred to as a photoconductor) in which the off-resistance of the semiconductor device 17 is reduced occurs. Light shielding films 16 and 19
Examples of the forming material include a material in which carbon is dispersed in an acrylic resin.

Also, an optimally mixed one of various primary color pigments (red, green, blue, cyan, magenta and yellow dyes), an insulating thin film formed of SiO ₂ or the like on the TFT 17, and a light shielding film formed on the insulating thin film A method of patterning and forming a metal thin film as an example is also exemplified. There is also a method of forming a light-shielding film by thickly depositing amorphous silicon. Further, T
The FT 17 preferably employs an inverted stagger structure in which a semiconductor layer is formed below a gate.

In the PD liquid crystal display device, the TFT 17
Is preferably formed by polysilicon technology so that a photo capacitor is not easily generated. The polysilicon technology includes a high-temperature polysilicon technology which is a semiconductor technology for fabricating a normal IC, or a low-temperature polysilicon technology for forming an amorphous silicon film which has been actively developed in recent years and crystallizing the film. In particular, it is preferable that the TFT is formed by a low-temperature polysilicon technology that can incorporate a drive circuit and can manufacture a panel at low cost. In the TFT formed by the above technology, the occurrence of the photoconductor phenomenon is much less likely to occur than in the TFT formed by the amorphous silicon technology which is currently used in pocket televisions and the like. Therefore, it is most suitable for a polymer dispersed liquid crystal display device that performs light modulation by scattering and transmission.

When PD liquid crystal is used as the liquid crystal material, there is a problem that scattered light lowers display contrast. Here, the scattered light countermeasures will be described with reference to FIGS.

As shown in FIG. 3, the light scattered by the liquid crystal layer 18 is reflected at the interface between the counter substrate 1A and the air, and is scattered back to the liquid crystal layer 18. This is called secondary scattered light. The secondary scattered light greatly reduces the display contrast of the PD liquid crystal display device.

In order to prevent the generation of the secondary scattered light, as shown in FIG. 5, a transparent substrate 31 is attached to the opposite substrate 1A. In the case of a transmission type liquid crystal display device, the transparent substrate 31 is attached to at least one of the panel entrance side 32 and the panel exit side 33. On the other hand, in the case of the reflection type liquid crystal display device, the transparent substrate 31 is attached to the panel incident side 32 via the optical coupling layer 35. The interface between the transparent substrate 31 and air is A
An IR coat film 39 is attached. Here, for the sake of simplicity, description will be made using a configuration in which a transparent substrate 31 is attached to a panel emission side 32 of a transmission type liquid crystal display device.

By attaching the transparent substrate 31, the reflected light 37 is not generated, and the reflected light 37 is absorbed by the light absorbing film 34 applied to the invalid area (the area where the effective light for image display does not pass) of the transparent substrate 31. You.

The light absorbing film 34 is exemplified by a black paint. Other materials for the light shielding films 16 and 19 can also be used. In addition, there is an effect even if the surface is roughened by polishing. These should be considered to be included in the concept of the light absorbing film 34.

When the transparent substrate 31 and the opposing substrate 1 A and the like are bonded by the optical coupling layer 35, air is prevented from entering the optical coupling layer 35. When an air layer is formed, image quality abnormality occurs due to a difference in refractive index. Therefore, the transparent substrate 31 and the like are arranged in a vacuum chamber, and the optical coupling layer 35 is injected between both substrates by a vacuum injection method. Just like injecting liquid crystal into a liquid crystal panel. The optical coupling using the optical coupling layer 35 or the like in this manner is called optical coupling (OC).

Here, as shown in FIG. 3, a parallel light beam is applied to the panel entrance side 32, and the luminance of the light modulation layer (liquid crystal layer 18) is measured from the panel exit side 33. The luminance B is such that the thickness t of the emission side substrate (including the sum of the thickness of the counter substrate 1A and the thickness of the transparent substrate 31 and the thickness of the coupling layer) is extremely thin with respect to the diagonal length of the effective display area, and This is the luminance measured when there is no absorbing film. Specifically, the thickness of the emission side substrate is 1 (mm) (t = 1) for d = 50 (mm).

In FIG. 4, the vertical axis represents the luminance ratio (Be / B), and the horizontal axis represents the relative substrate thickness (t / d). From FIG. 4, t / d
= 0.3, and when t / d <0.3, the rate of decrease in the luminance ratio (Be / B) is large. A small luminance ratio indicates a high display contrast. According to FIG. 4, when t / d = 0.25 to 0.3 or more, the contrast improving effect is sufficient, and t / d which is 1/2 of the previous t / d is sufficient.
It can be seen that /d=0.15 is within the practical range. Therefore, when the refractive index n of the substrate is 1.52, t / d is 0.1.
It is preferably 5 or more, and more preferably (t / d) is 0.3 or more. Therefore, the relationship between the thickness t of the transparent substrate and the diagonal length d of the panel may satisfy the following expression 1.

T / d ≧ 0.15 Expression 1 The transparent substrate 31 is not limited to a glass substrate. For example, it may be composed of a resin such as an acrylic resin or polycarbonate. Further, by using the transparent substrate 31 as an optical element such as a concave lens, the thickness of the substrate can be reduced. Further, if a positive lens is combined with a concave lens, the positive and negative optical powers can be eliminated by the concave lens and the positive lens, and it can be regarded as an apparently transparent substrate. When actually applied to the reflection type liquid crystal display device 1Z, the result is as shown in FIG.

When the light-shielding films 16 and 19 are formed of a resin, any material may be used as the light-absorbing material contained in the resin as long as the material has high electrical insulation and does not adversely affect the liquid crystal layer. For example, a black pigment or pigment dispersed in a resin may be used, or gelatin or casein may be dyed with a black acidic dye like a color filter. As an example of the black pigment, a single fluoran pigment which becomes black can be used by coloring, or a black color mixture of a green pigment and a red pigment can be used.

The above materials are all black materials.
The case where the liquid crystal display device of the present invention is used as a light valve of a projection display device is not limited to this. The projection type display device modulates three colors of light of R, G and B with three liquid crystal display devices. The light shielding films 16 and 19 of the liquid crystal display device for modulating the R light may absorb the R light. In other words, a light-absorbing material for a color filter may be modified so as to absorb a specific wavelength and used so as to obtain desired light-absorbing characteristics. Basically, similarly to the above-described black absorbing material, a material in which a natural resin is dyed using a dye or a material in which a dye is dispersed in a synthetic resin can be used.

The range of selection of the dye is broader than the black dye, and may be an appropriate one of azo dyes, anthraquinone dyes, phthalocyanine dyes, triphenylmethane dyes and the like, or a combination of two or more thereof.
Alternatively, as a measure against impurities in the light absorbing film, a dye (pigment)
The countermeasure can be taken by removing the alkali metal therein.

[0092] A black pigment such as carbon has many materials which adversely affect the liquid crystal layer. Therefore, use is not preferable. Therefore, it is preferable to employ a dye capable of absorbing a specific wavelength as the dye contained in the light absorbing thin film as described above.

Note that the adhesiveness to the liquid crystal layer 18 is improved by using the light shielding films 16 and 19 as a resin material. In particular, it is desirable to employ the same acrylic material as the resin material of the liquid crystal layer.

When the liquid crystal display device of the present invention is used as a light valve of a projection type display device, the light incident on the liquid crystal layer 18 may be scattered, causing halation or the like, or may be heated to deteriorate the liquid crystal panel.

The thickness of the light shielding films 16 and 19 is 0.1 μm of Cr.
m or more. However, if the thickness is too large, the surface may be uneven, and the TFT 17 may not be formed properly. Therefore, it should be kept to 0.2 μm or less.

With the above configuration, the light shielding film 1 is formed.
Reference numerals 6 and 19 prevent direct incident light from being incident on the semiconductor layer of the TFT 17 and also shield light reflected by the interface from light scattered by the liquid crystal layer 18. Note that the liquid crystal film thickness 18 of the liquid crystal panel is set with a sealing resin or beads.

In order to minimize the generation of surface reflected light at the interface with air, a glass substrate 31 provided with an AIR coat 39 is attached to the light incident surface via an optical coupling layer 35. This structure is as described above. Optical coupling layer 35
Examples of the material include ethylene glycol, epoxy resin, silicone resin, silicone adhesive, and acrylic adhesive. These have a refractive index of 1.40 to 1.50 or more, which is close to the refractive index of the glass substrate of 1.52, and does not generate unnecessary reflected light.

The antireflection film 39 has a three-layer structure or a two-layer structure. In the case of three layers, it is used to prevent reflection in a wide wavelength band of visible light, and this is called a multi-coat. In the case of two layers, it is used to prevent reflection in a specific visible light wavelength band, and this is called a V coat. The multi-coat and the V-coat are selectively used depending on the use of the liquid crystal display device. Usually, the V coat is adopted when a liquid crystal display device is used as a light valve of a projection display device, and the multi coat is adopted when the liquid crystal display device is used as a direct-view type panel.

In the case of multi-coating, aluminum oxide (Al ₂ O ₃ ) has an optical thickness of nd = λ / 4, zirconium (ZrO ₂ ) has nd 1 = λ / 2, and magnesium fluoride (MgF ₂ ) has nd 1 = λ. It is formed by laminating λ / 4. Normal,
A thin film is formed with λ set to 520 nm or a value near 520 nm. In the case of V coat, silicon monoxide (Si
O) is an optical film thickness nd1 = λ / 4 and magnesium fluoride (MgF ₂ ) is nd1 = λ / 4, or yttrium oxide (Y ₂ O ₃ ) and magnesium fluoride (MgF ₂ ) is nd1.
= Λ / 4. Since SiO has an absorption band on the blue side, it is better to use Y ₂ O ₃ when modulating blue light. Alternatively, Y ₂ O ₃ is preferable because the stability of the substance is more stable. Alternatively, n is the refractive index of each thin film, d1 is the physical thickness of the thin film, and λ is the design dominant wavelength.

The counter electrode 110 has a three-layer structure composed of a first dielectric thin film, an ITO thin film, and a second dielectric thin film in this order from the counter substrate 1A side. 2. The optical thickness of each of the first thin film and the second thin film is λ / 4. Note that the ITO thin film functions as a “counter electrode”.

The first thin film and the second thin film have a refractive index of 1.
It is desirably 60 or more and 1.80 or less. As an example, SiO,
Al ₂ O ₃ , Y ₂ O ₃ , MgO, CeF ₃ , WO ₃ , PbF ₂
Is exemplified.

Table 1 shows an example of a specific structure. First
According to the configuration shown in the table, characteristics with a reflectance of 0.1% or less can be realized over a wavelength bandwidth of 200 nm or more, and an extremely high antireflection effect can be obtained. In each table of the present invention, the refractive index of the liquid crystal layer 21 in the scattering state is set to 1.6, but this value changes if the liquid crystal material and the polymer material change. Assuming that the refractive index of the liquid crystal in the scattering state is nx, the refractive index of the first and second dielectric thin films is n1, and the refractive index of the ITO thin film is n2, the condition of nx <n1 <n2 is satisfied. Good. The optical film thickness 1 is a physical film thickness d × refractive index n
Is obtained.

[0103]

Table 1 Main wavelength: λ = 520 nm

The first thin film and the second thin film have a refractive index of 1.
It is desirably 60 or more and 1.80 or less. In each of the examples shown in Table 1, SiO was used. However, one or both of the thin films were used instead of Al ₂ O ₃ , Y ₂ O ₃ , MgO, CeF ₃ , and W.
Either O ₃ or PbF ₂ may be used.

Table 2 shows that the first thin film and the second thin film are Y2
The case where O3 is set is shown. In this case, the reflectivity tends to be slightly higher for the B light and the R light.

[0106]

Table 2 Dominant wavelength: λ = 520 nm

Table 3 shows the case where the first thin film is made of SiO and the second thin film is made of Y ₂ O ₃ . There is an extremely excellent antireflection effect of 0.1% or less over the entire visible light region.

[0108]

Table 3 Main wavelength: λ = 520 nm

Table 4 shows that the first thin film is made of Al ₂ O ₃ and the second thin film is made of Al ₂ O ₃ .
The case where the thin film of is made of SiO is shown. In the regions of R light and B light, the reflectance exceeds 0.5%, which is not appropriate.

[0110]

Table 4 Main wavelength: λ = 520 nm

As described above, by forming the dielectric thin film and the three layers on both sides of the ITO thin film, the effect of preventing reflected light can be obtained. Note that the spectral reflectance changes with a change in the refractive index of the liquid crystal layer 18. In other words, it depends on the liquid crystal material and the like, so that the optimization design is important.

When the liquid crystal layer 18 is in direct contact with the ITO thin film, the deterioration of the liquid crystal layer 18 tends to progress. This is presumably because impurities in the ITO thin film elute into the liquid crystal layer 18.
When a dielectric thin film is formed between the ITO thin film and the liquid crystal layer 18 as in the three-layer configuration described above, the liquid crystal layer 18 does not deteriorate. In particular, when the dielectric thin film is made of Al ₂ O ₃ or Y ₂
Good at O ₃ .

When the dielectric thin film is SiO, the refractive index of SiO tends to decrease. This is considered to be because SiO is combined with oxygen atoms such as H ₂ O and O ₂ contained in the liquid crystal 18 in a small amount, and SiO is changed to SiO ₂ . SiO does not change to SiO ₂ in a short time,
It can often be used in practice.

In the counter electrode 110, the optical film thickness of the first and second dielectric thin films was λ / 4 and the optical film thickness of the ITO thin film was λ / 2. The optical thickness of the dielectric thin film may be λ / 4, and the optical thickness of the ITO thin film may be λ / 4.

Further, according to the theory of the antireflection film, when N is an odd number of 1 or more and M is an integer of 1 or more, the optical film thickness of the first and second dielectric thin films is (N · λ). ) / 4, IT
The optical film thickness of the O thin film 271B may be (N · λ) / 4. Alternatively, the optical thickness of the first and second dielectric thin films is (N · λ) / 4, and the optical thickness of the ITO thin film is (M · λ).
λ) / 2.

Furthermore, one of the first and second dielectric thin films can be omitted. In that case, the performance as antireflection is somewhat reduced, but is often sufficient for practical use. Also in this case, the above-described theory of antireflection can be applied.

By forming the opposing electrode 110, reflected light can be prevented without entering the liquid crystal layer 18, so that the display contrast can be greatly improved.

Therefore, by forming a thin film made of an organic substance on the electrode, the charge retention can be improved. Therefore, high-luminance display and high-contrast display can be realized.

Next, the cooling module 1B will be described with reference to FIG.
This will be described with reference to FIG. The cooling module includes a reflecting plate 13 including a heat absorbing plate, a Peltier element pair 45, a radiating plate 12,
It is composed of a radiation fin 11 and the like. In addition, as a cooling method,
In addition to using the Peltier effect, a cooling method using a heat pipe (not shown) may be used.

The electronic cooling method using a Peltier element is small and lightweight, easy to handle and maintain, has a wide degree of freedom in shape, and is suitable for local cooling. Alternatively, the cooling / heating action can be realized only by switching the polarity, and a high-precision temperature control with high temperature responsiveness by current value control can be performed. Long life and high reliability if used within the rated specifications. When this cooling method is used for cooling a liquid crystal panel, it is possible to realize a liquid crystal display device which is small and capable of controlling the temperature with high accuracy.

Here, the cooling module 1B is shown in FIG.
This will be described in more detail with reference to FIG. In the cooling module 1B, the p-type semiconductor 42p and the n-type semiconductor 42n are paired via the heat absorbing plate 41 (FIG. 6), and more Peltier element pairs 45 connected in series are provided. This is a Peltier element pair group 54 connected in series (FIG. 7). The voltage V required to apply an electric field in the direction of n → p is as follows: V = nSΔT + IR Equation 2. n is the number of semiconductor elements incorporated in the cooling module 1B, S is the average Seebeck coefficient of the n-type semiconductor and the p-type semiconductor, and ΔT is the difference between the high temperature Th and the low temperature Tc of the semiconductor itself.

When a voltage V is applied to the Peltier element pair 45, heat is transferred from the heat absorbing plate 41 to the heat radiating plate 43 from the heat absorbing side to the heat radiating side. Considering the DC resistance component R of the Peltier element pair group 54, the endothermic amount Qin of endothermic plate 41 becomes Qin = nSTcI-1/2 · I 2 R-KΔT ... Equation 3. However, when a current flows through the DC resistance component R, power consumption P is generated.

P = VI = nSΔTI + I ² R (Equation 4) Accordingly, the heat radiation amount Qout of the heat sink 43 is as follows: Qout = Qin + P = nSThI + 1/2 · I ² R−KΔT (Equation 5)

When this heat radiation amount Qout is constantly and efficiently radiated by the heat radiation fins 11 and the small cooler 1C, heat from the low temperature side can be sequentially pumped to the heat radiation side. K is the heat transmission coefficient of the cooling module 1B, and I is the current flowing through the cooling module 1B. That is, the current becomes energy for pumping heat. That is, by controlling the current, the amount of heat to be pumped can be changed, and the temperature of the liquid crystal panel can be controlled. The panel temperature can also be controlled by controlling the cooling capacity of the small cooler. However, when the rated current value of the cooling module 1B is exceeded, the Joule heat loss (１ ／ · I ² R) and the heat conduction loss (KΔT) exceed the Peltier action (nSTcI), and the cooling effect gradually decreases. Further, if the heat radiation fins do not sufficiently dissipate heat, the Peltier element may be destroyed.

The shape of the radiation fins 11 is the same as that of the fins 1.
1 and the direction of air flow of the cooler 1C to be cooled. The smaller the thermal resistance, the better the cooling capacity of the system.

The heat resistance of the radiating fins 11 varies depending on the direction in which the cooling air flows. As the small cooler 1C, a small cooling fan 1C1 used for cooling a CPU (Central Processing Unit) of a personal computer is used (FIG. 8). Since the small-sized cooling fan 1C1 is self-cooling, the temperature rise of the small-sized cooling fan itself does not need to be considered in the thermal design.

When the air is blown in the air blowing direction 61 shown in FIG.
1 is determined so that the thermal resistance becomes smaller. For example, each fin of the radiation fins 11 may be replaced with a small cooling fan 1C.
One blade is distributed along the rotation direction. The fins 63 have a wing-shaped cross-sectional area so that the wind can flow smoothly (FIG. 10A), and the fins 64 have a square or circular cross-sectional area (FIG. 10B). I assume. The fin 65 has a spiral shape in order to further reduce the thermal resistance of the fin 66 having a concentric shape (FIGS. 10C and 10D).

Further, when cooling the entire reflection type liquid crystal display device 1Z, the small cooling fan 1C1 is arranged as shown in FIG. At this time, the radiation fins 11 reduce the thermal resistance of the small cooling fan 1C1 in the air blowing direction.
As shown in FIG. Any other fin shape may be used as long as the fin shape reduces the thermal resistance. Further, as shown in FIG.
When 1 is provided, as shown in FIG. 13, the heat resistance of the fin 11 is further reduced, and a higher cooling effect can be obtained.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to FIG. In the liquid crystal display device 8Z, beads 81 for transmitting heat absorbed by the counter substrate 1A to the array substrate 14 are inserted into the liquid crystal layer 18 of the liquid crystal display device 1Z. Further, in order to enhance the insulating property between the counter electrode 110 and the pixel electrode 15, an insulating film 82 is provided on the entire surface of each of the counter electrode 110 and the pixel electrode 15 over the entire substrate.

Examples of the insulating film 82 include an alignment film such as polyimide used for a TN liquid crystal display device, an organic material such as polyvinyl alcohol (PVA), and an inorganic material such as SiO 2. Preferably, an organic substance such as polyimide is preferable from the viewpoint of adhesion and the like.

The polymer-dispersed liquid crystal 18 has a relatively low specific resistance. Therefore, the electric charge applied to the pixel electrode 15 may not be completely held during one field (1/30 or 1/60 second) of the video signal. If the liquid crystal layer 18 cannot be held, the liquid crystal layer 18 will not be completely transparent, and the display brightness will be reduced. A thin film made of an organic substance such as polyimide has a very high specific resistance.

The insulating film 82 also has an effect of preventing the liquid crystal layer 18 from being separated from the electrode. This is because about half of the material constituting the liquid crystal layer 18 is an organic substance made of resin. Therefore, the insulating film 82 plays a role of an adhesive layer, and peeling between the substrates 15 and 1A and the liquid crystal layer 18 hardly occurs.

The formation of the insulating film 82 made of an organic substance also has the effect of making the pore size of the polymer network of the liquid crystal layer 18 or the particle size of the liquid crystal in the form of water droplets substantially uniform. This is because even if an organic residue remains on the counter electrode 110, the organic residue is covered with the insulating film 82. The effect is better with PVA than with polyimide. This is probably because PVA has higher wettability than polyimide. However, according to the results of reliability (light resistance, heat resistance, etc.) tests performed by fabricating various insulating films 82 on the panel, the polyimide used for the alignment film of the TN liquid crystal showed good results with almost no change over time. is there. Therefore, polyimide is used as the insulating film 82.
It is preferable to use them.

When forming the insulating film 82 with an organic material,
The film thickness is preferably in the range of 0.02 μm or more and 0.1 μm, and more preferably 0.03 μm or more and 0.08 μm or less.

Beads 81 for controlling the thickness of the liquid crystal layer 18
Uses black glass beads 83 or black glass fibers having good thermal conductivity, or black resin beads or black resin fibers. In particular, black glass beads or black glass fibers are preferable because they have a very high light-absorbing property and are hard, so that a small number of particles are scattered on the liquid crystal layer 21.

Although the beads and fibers are black in the above description, the present invention is not limited to the case where the liquid crystal display device of the present invention is used as a light valve of a projection display device. The projection type display device modulates three colors of light of R, G and B with three liquid crystal display devices.
The beads or the like used for the liquid crystal display device that modulates the R light may absorb the R light. That is, beads containing a dye that is complementary to the color of the light to be modulated may be used. For example, for blue light, it is yellow.

The liquid crystal layer 21 scatters (displays black) incident light when no voltage is applied. When transparent beads are used, even in a black display, light leakage occurs from the beads and the display contrast is reduced. If black glass beads or black glass fibers are used as in the liquid crystal display device of the present invention, light leakage does not occur and good display contrast can be realized.

The insulating film 82 should be as thick as possible. At least 0.2 μm or more. This is the light shielding film 16, 1
This is because the unevenness of the TFT 9 is smoothed and the parasitic capacitance between the gate of the TFT 17 and the light shielding film 16 is reduced.

In the second embodiment of the present invention, it goes without saying that all the configurations, functions, materials, and the like described in the first embodiment can be applied.

(Embodiments 3 and 4) Next, Embodiments 3 and 4 of the present invention will be briefly described. As shown in FIG. 15, in the third embodiment, in FIG. 1, the counter substrate 1A (including the light shielding film 19 formed on the substrate 1A) and the array substrate 14 (the substrate
(Including TFT 17 and light shielding film 16 formed above)
Are reversed.

That is, the incident light first enters the array substrate 14 side, passes through the liquid crystal layer 18, and enters the opposite substrate 1A. The reflection plate 13 is provided with a reflection film on the counter electrode 110, or on the liquid crystal layer 18 side of the heat absorption plate 12 as in the case of FIG. At this time, if the opposing substrate 1A-side light-shielding film 19 is provided on the array substrate 14, the light-shielding effect is effective to prevent the photoconductor phenomenon.

Next, a fourth embodiment is shown in FIG. This configuration is different from the configuration of the third embodiment in that beads 81 for transmitting heat absorbed by counter substrate 1A to array substrate 14 side.
Is inserted. Further, in order to enhance the insulating property between the counter electrode 110 and the pixel electrode 15, an insulating film 82 is provided on the entire surface of each of the counter electrode 110 and the pixel electrode 15 over the entire substrate. In this case, similarly to the third embodiment, when the light shielding film 19 on the counter substrate 1A side is provided on the array substrate 14 side, the light shielding effect is improved.

In the third and fourth embodiments of the present invention, it goes without saying that all the configurations, functions, materials, and the like described in the first embodiment of the present invention can be applied.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIGS. The liquid crystal display device can be configured by forming a liquid crystal panel, a horizontal driver circuit, and a vertical driver circuit on a glass substrate using a low-temperature polysilicon technology. However, the formed M
A phase shift may occur in a liquid crystal driving pulse of a source drive circuit or a gate drive circuit due to a variation in electrical characteristics of an OS element or the like. When a shift pulse is operated by inputting a start pulse to the source drive circuit system and the gate drive circuit system, and the video signal input to the liquid crystal display device is sequentially latched, if there is a variation in the electrical characteristics of each element, it is ensured that May not be able to latch the video signal.

As shown in FIG. 17A, due to variations in electrical characteristics of MOS elements and the like that occur when a liquid crystal panel is manufactured, positions between pulses 11G, 11R, and 11B for driving a source drive circuit and a gate drive circuit are changed. Phase difference Δ
T ′ or ΔT ″ may occur, and when the shift register is operated to sequentially latch the G signal, the R signal, and the B signal, the driver circuits 12S and 12G malfunction,
Sometimes latching cannot be done reliably.

In order to eliminate the phase difference, as shown in FIG. 17 (b), a clock pulse 112 transmitted from a timing control clock generation circuit 111 is supplied to a timing signal provided for each of the G, R and B signal systems. Control circuit 11
3, 114 and 115. The control circuit 11
At 3, 114 and 115, the number of clock pulses 112 required for desired control is counted, and each G, R, B signal system having a specific pulse timing and pulse width according to the number of pulse counts. Driver circuit driving pulse 1
16, 117 and 118 are generated.

When this signal control system 11Z is used, each G,
The R and B video signals can be latched without a phase difference. Further, if necessary, drive pulses 116, 117,
118, the phases ΔT1, ΔT2, ΔT3 can be controlled.

In this embodiment, the signals to be controlled are supplied to the driver circuits 12S, 12G driving pulses 116, 11G.
7, 118, but the signals to be controlled are not limited to this, and the signal control system 11Z is used for phase control between various signals having variations.

The signal control system 11Z is connected to the driver circuits 12S, 12G using the low-temperature polysilicon technology.
When formed on a single glass substrate together with the liquid crystal display unit 12L and the liquid crystal display unit 12L, it is possible to manufacture a compact and highly reliable liquid crystal module 12M (see FIG. 18).

(Embodiments 6 to 8) Next, Embodiments 6, 7 and 8 of the present invention will be described. These embodiments relate to a projection display device using a liquid crystal display device.

First, a common concept regarding the projection type display device will be described. The following values or value ranges are particularly important for a projection display device using a liquid crystal display device using a polymer-dispersed liquid crystal as a light modulation layer as a light valve.

In the projection display device of the present invention, from the viewpoint of improving the light utilization factor, if the panel effective display size (display area of the panel) is reduced, the F-number of the illumination light needs to be increased. If the panel effective display size d is increased, the F number of the illumination light can be reduced, and as a result, a bright large-screen display can be realized. However, when the panel effective display size increases, the system size of the projection display device increases, which is not preferable. Alternatively, if the effective display size of the panel is reduced, the luminous flux per unit area incident on the display area of the panel increases, which is not preferable because the panel is heated.

The luminance of the luminous body of the lamp is fixed at 1.2 × 10 8 (nt) in consideration of the lamp life. It is considered that the arc length and lamp power consumption are approximately proportional. The efficiency of the metal halide lamp is 80 (lm / W). 50
The total luminous flux of the lamp of (W) is 4000 (lm), 100
The total luminous flux of the lamp of (W) is 8000 (lm), 150
The total luminous flux of the lamp of (W) is 12000 (lm).
There is a correlation between the arc length of the lamp and the lamp power consumption, and there is a correlation between the arc length and the F number.

In the projection type display device, the projected image must have a screen size of 40 inches or more, and a light flux of 300 to 400 (lm) or more is required in order to obtain a viewing angle and image brightness in a practical range. Therefore, if the light utilization factor of the lamp is about 4%, a lamp of 100 (W) or more must be used.

If the panel effective display size is small, sufficient display luminance cannot be obtained. Assuming that the arc length is 3-4 (mm) and the effective F value of the illumination light is 7, the panel effective display size needs to be about 3.5 inches.
Arc length is about 5 (mm), panel effective display size is 2
If the inch is slightly greater, the effective F value of the illumination light is less than 5. In this case, display luminance is in a practical range, but good display contrast (CR) cannot be expected.

As a result of experiments and studies on the above, it is necessary that the arc length a (mm) and the diagonal length d (inch) of the effective display (image display range) area of the panel satisfy the following relationship.

A (mm) ≦ d (inch) Expression 6 The diagonal length of the effective display area of the panel must be 5 inches or less from the viewpoint of the system size. Alternatively, it must be at least 1.0 inch from the viewpoint of light use efficiency.
Above all, in order to obtain a sufficient light focusing efficiency and to make the device compact, it is preferable that the thickness be 1.5 to 4.5 inches.

The F number of the projection lens, in a broad sense, the F number of the projection optical system must be 5 or more in order to obtain a good contrast (CR). Also, it must be 10 or less in order to obtain sufficient screen brightness.
Further, considering the arc length of the lamp described above, the F number must be 6 or more and 10 or less.

If the divergence angle (F number) of the illumination light does not substantially coincide with the converging angle (F number) of the projection lens, the light utilization rate decreases. This is because the restriction is imposed on the larger F number. In the projection display device of the present invention, the F number of the illumination light and the F number of the projection lens are made to match.

In the above description, for example, an arc length of a lamp of 5 mm means “substantially 5 mm”. Substantially 5 mm means that the arc length is 8 mm
However, if the projection lens of the light emitted from the arc can collect only the light emitted from the vicinity of 5 mm at the center of the arc, the arc length becomes substantially 5 mm. Similarly, the F number means an effective F number.
Even if the physical F number is 4, if the light passes only near the center of the pupil of the projection lens, the F number is naturally 4 or more.

Referring to FIG. 19, the configuration of a projection type display device using a reflection type liquid crystal display device or the like according to the sixth embodiment of the present invention as a light valve will be described. In FIG.
138 is a dichroic mirror (RD) that reflects R light
M) and 13A are dichroic mirrors (GDM) that reflect G light, and 139 is a total reflection mirror or dichroic mirror (RDM) that reflects R light. In addition,
The arrangement of the RDM 138 to the GDM 13A and the total reflection mirror 139 are not limited to the order shown in FIG.

The thickness of the liquid crystal layer 18 of the liquid crystal display device 1Zr for modulating R light is made thicker than the thickness of the liquid crystal layer 18 of the liquid crystal display devices 1Zg and 1Zb for modulating other G and B lights. I do. In addition, the average particle size of the liquid crystal droplets or the average pore size of the polymer network is changed according to the wavelength of the light to be modulated. The longer the wavelength of the modulated light, the larger the average particle size or average pore size. This is because the longer the wavelength of light, the lower the scattering characteristics and the lower the contrast.

Hereinafter, the operation of the projection type display device of the present invention will be described. The R, G, and B light modulation systems have almost the same operation, and therefore the B light modulation system will be described as an example.

The projection lens 13D includes a first lens group 135 on the liquid crystal display device 1Zb side and a second lens group 1 on the screen side.
3C, and a plane mirror 134 is disposed between the first lens group 135 and the second lens group 13C.
After passing through the first lens group 135, about half of the scattered light emitted from the pixel at the center of the screen of the liquid crystal display device 1Zb enters the plane mirror 134, and the rest enters the second lens without entering the plane mirror 134. The light enters the group 13C. The normal to the reflection surface of the plane mirror 134 is the optical axis 137 of the projection lens 13D.
45 °. Light from the light source 13F is reflected by the plane mirror 134, passes through the first lens group 135, and enters the liquid crystal display device 1Zb. Liquid crystal display 1Z
The reflected light from b is transmitted through the first lens group 135 and the second lens group 13C in this order and reaches the screen 13E. The liquid crystal display device 1Z exits from the center of the stop of the projection lens 13D.
The light beam directed to b is made to enter the liquid crystal layer 18 almost perpendicularly, that is, telecentric.

In FIG. 19, dichroic mirror 1
Reference numerals 38 and 13A serve both as a color synthesis system and a color separation system. The white light emitted from the light source is reflected by the plane mirror 134 and enters the first group 135 of the projection lens 13D. The band of the UVIR cut filter 133 is 43 at half value.
0 nm to 690 nm. Hereinafter, when describing the band of light, it is expressed by a half value.

The dichroic mirror 138 reflects the R light and transmits the B light and the G light. The R light is band-limited by the dichroic mirror 138 and enters the liquid crystal display device 1Zr. The band of the R light is 600 to 690 nm.

On the other hand, the dichroic mirror 13A reflects the B light and transmits the G light. G light is the liquid crystal display 1Z
At g, the R light enters the liquid crystal display device 1Zb. The band of incident B light is 430 nm to 490 nm, and the band of G light is 5
It is 10 nm to 570 nm. The bands of these lights are the same for the other projection display devices of the present invention. In each of the liquid crystal display devices 1Zr, 1Zg, and 1Zb, an optical image is formed as a change in a scattering state in accordance with each video signal. The optical system formed by each of the liquid crystal display devices 1Zr, 1Zg, and 1Zb is color-combined by dichroic mirrors 138 and 13A.
The light enters the projection lens 13D and is enlarged and projected on the screen 13E.

The light incident on the liquid crystal display device 1Z is
From the counter electrode 15 to the reflector 13 (incident path), the reflector 13
, And passes through the liquid crystal layer 18 twice. Therefore, apparently,
This is equivalent to forming the liquid crystal film twice as thick as the transmission type liquid crystal display device. Therefore, the scattering performance is improved as compared with the transmission type liquid crystal display device, and high contrast display can be realized.

The dichroic mirrors 138 and 13A are
It functions as a filter that reflects (transmits) light of a specific wavelength. For example, the dichroic mirror 138 reflects light of a specific wavelength (600 to 690 nm) when the light from the light source 13F enters the liquid crystal display device 1Zr. Alternatively, when the light reflected by the liquid crystal display device 1Zr enters the projection lens 13D, light of a specific wavelength (600 to
690 nm). That is, one dichroic mirror 138 reflects light twice when it enters the liquid crystal display device 1Zr and when it exits.

In the configuration shown in FIG. 19, one dichroic mirror 138 limits the wavelength band of light twice. That is, the dichroic mirror 138 functions as a secondary filter. Further, the dichroic mirror 138 serves both as a color separating function and a color synthesizing function, thereby realizing a reduction in system size of the projection display device. Exactly the same operation can be realized with respect to the dichroic mirror 13A, and a description thereof will be omitted. If a mosaic color filter is attached to the PD liquid crystal display device 1Z, a single liquid crystal display device can display a color image.

In the projection type display device using the reflection type liquid crystal of the present invention shown in FIG. 19, it is necessary to pay attention to the incident direction and the outgoing direction of the light incident on the light separating surface (for example, the dichroic mirror 138). Specifically, FIG.
It is necessary to configure as shown in FIG. That is, FIG. 19 is displayed only for ease of illustration and description. Hereinafter, the reason why the configuration should be as shown in FIG. 20 will be described.

In the case of the configuration shown in FIG. 19, the light emitted from the light source 13F and the optical axis 136 of the illumination light illuminating the liquid crystal display device 1Z, and the screen 13E reflected by the liquid crystal display device 1Z via the projection lens 13D. The optical axis 13B of the projected light reaching the dichroic mirrors 138 and 13A
Are incident at different angles.

The dichroic mirrors 138 and 13A are generally formed by depositing a dielectric multilayer film on a transparent substrate and transmitting or reflecting light in a specific wavelength band. This type of dichroic mirror has the characteristic that the spectral characteristic curve shifts to the short wavelength side when the incident angle of the light beam increases, and when the optical axis 136 and the optical axis 13B enter at different angles as shown in FIG. However, since spectral characteristics for color separation and spectral characteristics for color synthesis are different from each other, it is difficult to obtain a projected image with desired color purity.

The PD liquid crystal display device 1Z does not have such a strong dependence of the optical characteristics on the incident angle as the TN liquid crystal display device. However, when the incident angle of the incident light is too large, the optical path length when passing through the liquid crystal layer 18 is small. The scattering characteristics change due to the lengthening. That is, if the incident angle of the light beam incident on the PD liquid crystal display device 1Z differs depending on the location, the image quality of the projected image becomes non-uniform.
If a positive lens is combined with a concave lens described later instead of the transparent substrate 31 for the OC, the PD liquid crystal display device 1 can be formed without increasing the size of the projection lens 13D.
Since light nearly parallel to Z can be made incident, it is easy to ensure image quality uniformity of the projected image.

In the configuration of the projection display device shown in FIG. 20, the optical axis 136 of the illumination light and the optical axis 1 of the projection light reflected by the liquid crystal display device 1Z and projected by the projection lens 13D are used.
3B can be symmetrical with respect to a plane including the center normal of the liquid crystal display device 1Z and the center normal of the light separation surface such as a dichroic mirror. Therefore, the angles of incidence on the light separation surface can be made equal to each other. Therefore, the spectral performance after color separation matches the spectral performance after color synthesis, and the screen 13E
The projected image displayed above can obtain a desired color purity.

As is clear from the above, the advantage of the projection type display device shown in FIG. 20 is that the color purity is excellent and the color uniformity is excellent when the reflection type liquid crystal display device utilizing natural light is used. Display of a projected image can be easily realized.

The dichroic mirrors 138 and 13A are formed by depositing a dielectric multilayer film in which low refractive index layers and high refractive index layers are alternately laminated on a glass substrate, and each of the color separation / combination surfaces (light separation surfaces) is provided. Liquid crystal display devices 1Zr, 1Zg, 1Z
The light modulation layer (liquid crystal layer) 18b is arranged at an angle of 45 °.

The light emitted from the lamp 13F sequentially enters the dichroic mirrors 138 and 13A via the cold mirror 133 and the mirror 134. The light incident on the dichroic mirrors 138 and 13A is separated into three primary color lights of R, G, and B, and the three corresponding liquid crystal display devices 1Z respectively.
r, 1Zg, and 1Zb, and the reflected light again enters the dichroic mirrors 138 and 13A. R, G, B
Are synthesized by dichroic mirrors 138 and 13A, transmitted through aperture stop 141, and then enlarged and projected on screen 13E by projection lens 13D.

Of the light incident on the liquid crystal display devices 1Zr, 1Zg, and 1Zb, the light incident on the pixels in the scattering state and reflected as the scattered light is reflected by the aperture stop 141 of the projection lens or the lens barrel (not shown). Most of them are shielded from light by the inner wall of (1) and black display is performed. On the other hand, the light that enters the pixel in the non-scattered (transmitted) state and travels after being regularly reflected is projected by the projection lens 13.
The light passes through the lens group forming the aperture stop 141 of D and the projection lens 13D, and reaches the screen 13E as white display. Thus, the liquid crystal display devices 1Zr, 1Zg,
An optical image modulated as a scattering mode and a non-scattering (transmission) mode on 1Zb is displayed on a screen as a projection image.

Similarly, the technical idea of considering the incident angles of the projection light and the illumination light on the dichroic mirrors 138 and 13A can be applied to other reflection type projection display devices as they are, and will be described later. CC
It goes without saying that the same can be applied to the case where a D prism is used.

Embodiment 7 of the present invention will be described with reference to FIGS. 21 and 22. FIG. 21 is a configuration diagram of a projection display device that performs color separation and color synthesis using the dichroic prism 151. Reference numeral 154 denotes a field lens for efficiently irradiating the illumination light from the light source 13F to the liquid crystal display device 1Z. The dichroic prism 151 has two light separation surfaces 152r and 152b. The light separation surface 152 separates white light into R, G and B primary color lights. Each of the liquid crystal display devices 1Zr, 1Zg, and 1Zb is attached to the dichroic prism 151 via the optical coupling layer 153. That is, the dichroic prism 151
Is provided with an optical coupling (O
C) It is pasted. A light absorbing film 155 is applied to an invalid area of the prism 151 (an area through which light effective for image display does not pass).

In FIG. 21, it is assumed that the liquid crystal display device 1Zr modulates the R light, and the light separating surface 152r reflects the R light.
The incident light is reflected by the light reflecting surface 152r and is reflected on the liquid crystal display device 1Z.
r enters the light modulation layer (liquid crystal layer) 18. Light modulation layer 18
Is scattered according to the magnitude of the voltage applied to the pixel electrode 15. The light that has not been scattered is reflected again by the light separation surface 152r and becomes emitted light. Most of the scattered light enters the light absorbing film 155 formed in the invalid area of the prism 151 and is absorbed.

Most of the light scattered by the liquid crystal layer 18 as described above is absorbed by the light absorbing film 155. Therefore, the scattered light does not become the emitted light 13B. Note that the operation of the liquid crystal display devices 1Zb and 1Zg is the same as that of 1Zr, so that the description is omitted. However, the irradiation light to the liquid crystal display device 1Zg is applied to the light separation surface 152r in the dichroic prism 151,
152b. The light absorbing film 155 is a TFT.
The light-shielding films 16 and 19 on 17 are formed of the same material. Further, a black paint or a dye or a dye having a complementary color with the light modulated by the liquid crystal display device 1Z may be applied. Also,
A configuration in which the invalid area is roughened to be cloudy may be used. Further, a black plate or the like may be attached.

The configuration in which the liquid crystal display device 1Z is optically coupled to the prism 151 and the light absorbing film 155 is formed or arranged in an invalid area of the prism 151 is also applicable to the configuration of a transmission type liquid crystal display device (not shown). can do.

FIG. 22 shows a radiation fin 1 for the liquid crystal display 1Z attached to the dichroic prism 151.
61 shows the shape of the reference numeral 61. Each liquid crystal display 1Z
r, 1Zg, and 1Zb, the heat radiation fins 11 are integrated to efficiently dissipate the heat generated by the liquid crystal display device 1Z.
g was blown from the small cooling fan 1C1. The fin 161g located on the back surface of the liquid crystal display device 1Zg has a circular shape or a spiral shape like 65 and 66 described above, and the fins 161r and 161b on the back surface of the liquid crystal display devices 1Zr and 1Zb have small thermal resistance in the blowing direction. In this case, the fin shape was thin. Alternatively, the fins 161r and 161b may be streamlined such as 72.

Each of the liquid crystal display devices 1Zr, 1Zg, 1
Exclusive radiation fin 11 and small cooling fan 1C1 for each Zb
May be provided. With such a configuration, each liquid crystal display device 1Z
A unique temperature control can be performed for each of r, 1Zg, and 1Zb in accordance with the energy of the incident light.

Next, a method of increasing the display contrast while maintaining high luminance display in the projection type display device will be described in the eighth embodiment. FIG. 23 is a configuration example for realizing the above method. Projection lens 13D
Is composed of a front lens group 13C and a rear lens group 135.

The input section converging lens array 176 is constituted by arranging a plurality of input section converging lenses 175 two-dimensionally. FIG. 24 shows an example of the configuration. Ten input part converging lenses 175 having a rectangular opening are arranged so as to be inscribed in a region of a perfect circle. 10 input part converging lenses 1
Reference numeral 75 denotes a plano-convex lens having the same opening shape, and the ratio of the long side to the short side of the rectangular opening is 4: 3.

Similarly, the central convergent lens array 177 is
A plurality of central converging lenses 178 are arranged two-dimensionally. The central convergent lenses 177 having the same number and the same aperture as the input convergent lenses 175 are arranged in the same manner as the input convergent lens array 176.

The procedure of illumination in the projection type display device will be described. The light radiated from the luminous body of the metal halide lamp 131 is reflected by the parabolic mirror 132 to form an optical axis 137.
Travels approximately parallel to the UVIR cut filter 174
Pass in parallel and enter the input part converging lens array 176. Since the cross-sectional shape of the light emitted from the parabolic mirror 132 is generally a perfect circle, the input section converging lens array 17 is set so that the total aperture of the input section converging lens 175 is inscribed therein.
6 is constituted. The light passing through the input section converging lens array 176 is divided into the same number of partial light beams as the input section converging lens 175, and each partial light beam illuminates the display area of the PD liquid crystal display device 1Z.

The light that has passed through the input section converging lens 175 is
Each is guided and converged by the opening of the corresponding central convergent lens 177. A secondary illuminant 184 is formed on each opening of the central converging lens 177. Plural secondary light emitters 184 formed on central convergent lens array 178
Is schematically shown in FIG. Central focusing lens 1
Reference numerals 77 each effectively transmit the corresponding light onto the display area of the PD liquid crystal display device 1Z. Specifically, a real image of the object on the main plane of the corresponding input part converging lens 175 is formed near the display area of the PD liquid crystal display device 1Z. However, each central convergent lens 177 is appropriately decentered, and forms one real image by superimposing a plurality of images.

According to the above configuration, the PD liquid crystal display device 1
The display area of Z and the respective apertures of the input section converging lens 175 have an approximately conjugate relationship with each other. Therefore, if the opening of the input section converging lens 175 has a shape similar to that of the display area of the PD liquid crystal display device 1Z, the cross section of the illumination light and the shape of the display area can be matched to suppress light loss. Therefore,
The input part converging lens array 176 shown in FIG.
It may be used in combination with a PD liquid crystal display device 1Z that displays an image having an aspect ratio of 4: 3 corresponding to SC.

Generally, light emitted from a concave mirror 132 such as a parabolic mirror has relatively large brightness unevenness. PD liquid crystal display device 1 by transmitting light with large uneven brightness as it is
Illuminating Z reduces the brightness uniformity of the projected image. When the illumination is performed using only the region having relatively uniform brightness, the unusable light increases, so that the light use efficiency decreases. On the other hand, the projection type display device of the present invention has an advantage that a high light use efficiency can be obtained and a projection image with excellent brightness uniformity can be obtained. The reason is described below.

The input section converging lens array 176 divides light having a large uneven brightness into a plurality of partial light beams. The brightness unevenness of each partial light beam on the opening of the input unit converging lens 175 is smaller than the brightness unevenness of the light beam cross section before division. Each of the central converging lenses 177 enlarges the partial light beam with less uneven brightness to an appropriate size and superimposes it on the display area of the PD liquid crystal display device 1Z. Therefore, illumination with good brightness uniformity can be realized.

Since the sum of the apertures of the input section converging lens 175 is inscribed in the cross section of the incident light beam, light loss in the input section converging lens array 176 is small. Alternatively, since each of the apertures of the central convergent lens 177 is sufficiently large with respect to the secondary luminous body 184, the central convergent lens array 1
The light loss at 78 is low. Furthermore, since the cross section of the light incident on the PD liquid crystal display device 1Z is matched to the shape of the display area, light loss in the PD liquid crystal display device 1Z is small.
Therefore, most of the light emitted from the illuminant is reflected by the parabolic mirror 132, and the input part converging lens array 1
76, a central convergent lens array 178, an output convergent lens (not shown), and a PD liquid crystal display device 1Z to reach the projection lens 13D. Therefore, the projection lens 13
If the light loss in D is suppressed, a high light use efficiency is realized, and a bright projected image with excellent brightness uniformity is obtained.

By the way, the central convergent lens array 178
A plurality of secondary light emitters are discretely formed on the upper surface.
Therefore, the effective F number of the illumination light in this case needs to be determined from the irradiation angle equivalently converted from the total sum of the areas of the secondary luminous bodies. On the other hand, the condensing angle of light emitted from the PD liquid crystal display device 1Z at the most angle with the optical axis 137 is
The value is larger than the equivalent irradiation angle. Therefore, in order to suppress light loss, the effective F-number of the projection lens 13D needs to be smaller than the effective F-number of the illumination light. This causes a problem in the case of a PD liquid crystal display device because the contrast of a projected image is reduced.

On the other hand, in the projection type display device of the present embodiment, the apertures 186 and 187 as shown in FIG. In any case, the size can be reduced to a necessary minimum, so that a decrease in contrast can be suppressed. In particular,
According to the effective area of the discretely formed secondary light emitter,
The aperture of the stop 186 on the illumination light side has a shape as shown in FIG. The broken line indicates the central convergent lens 1 in FIG. 24 or FIG.
77 corresponds to each opening. Also, the projection lens 13D
Since the real image of the secondary luminous body is formed on the opening of the stop 187 on the side, the opening shape of the stop 187 is made similar to the opening shape of the stop 186.

As a result, since the light passing through the stop 186 passes through the stop 187, high light use efficiency can be realized. At the same time, the projection lens 13D provides the minimum necessary aperture required by the illumination light, so that a display image with high contrast can be realized. As a result, a bright and high-quality projected image can be provided, and a very large effect can be obtained.

The input part convergent lens array 176 and the central part convergent lens array 17 used in the projection type display device of the present invention
8, the illumination side stop 186 and the projection side stop 187 are more preferably configured as follows. FIG. 27 shows the configuration of the central convergent lens array 178 in this case. In general, the size of the secondary illuminant is larger as the input portion converging lens 175 located near the optical axis is formed. Therefore, the respective apertures of the central convergent lens 177 do not necessarily have to be the same, and may have a size sufficient for each of the secondary light emitters.

If a plurality of central convergent lenses 177 having effectively different apertures are arranged in an aggregating manner to form a central convergent lens array 178, there is an advantage that the sum of the aperture regions can be reduced. The input convergent lens array 176 combined with the central convergent lens array 178 is constructed in the same manner as that shown in FIG. 25, and each of the input convergent lens 175 is appropriately decentered and the aperture of the corresponding central convergent lens 177 is opened. What is necessary is just to form a secondary luminous body at the center.

In this case, it is preferable to use an aperture stop 188 having an aperture shape shown in FIG. 28 instead of the stop 186 on the illumination light side.
The same applies to the stop 187 on the projection lens side. Accordingly, the aperture diameter of the central convergent lens array 178 can be reduced without causing light loss, and the projection lens 1
There is an advantage that a 3D lens diameter can be reduced.

As described above, the projection display apparatus of the present embodiment provides a greater effect when the light valve 1Z is illuminated by forming a plurality of secondary light emitters discretely.
Even if the projection lens 13D having a large maximum light collection angle is used, by providing a diaphragm having a plurality of apertures discretely,
It is possible to provide a minimum necessary opening for light emitted from the light valve 13D. As a result, a bright and high-contrast projected image can be obtained. Or, stop 187
The rear lens group 135, the field lens (not shown), and the like are appropriately configured so that the lens and the aperture 186 have a conjugate relationship with each other.

In the PD liquid crystal display device 1Z, an optical image corresponding to three primary colors is formed on each display area according to a video signal supplied from the outside. The projection lens 13D
The front lens group 13C and the rear lens group 135
The optical image of the primary color is enlarged and projected on the screen 13E. P
Light emitted from the D liquid crystal display device 1Z is combined into one optical path by the functions of the dichroic mirrors 138 and 13A and the plane mirror 139, so that a full-color projected image is obtained.

A plane-concave lens shape 172 is connected to the exit side of the PD liquid crystal display device 1Z using a transparent adhesive with the concave surface facing the exit side, and a black paint for light shielding is applied to the side surface of the lens 172, and the concave surface is formed. Has an anti-reflection film deposited thereon. The plano-concave lens 172 is formed by molding using acrylic resin. In molding, the same lens can be produced if there is a mold, so mass production is good.

The positive lens 1 is located on the exit side of the concave lens 172.
71 are arranged in close proximity. The radius of curvature of the convex surface of the positive lens 171 is equal to the radius of curvature of the concave surface of the concave lens 172. A thin air gap is provided between the convex surfaces of both lenses.
Antireflection films are deposited on both surfaces of the positive lens 171 similarly to the plano-concave lens 172. Also, the projection lens 13D
In a state where the concave lens 172 and the positive lens 171 are combined, an optical image on the liquid crystal layer 18 is formed on the screen 13E. The focus adjustment of the projection image is performed by moving the projection lens along the optical axis 137.

The PD liquid crystal display device 1Z does not have such a strong dependence of the optical characteristics on the incident angle as the TN liquid crystal display device. However, when the incident angle of the incident light is too large, the optical path length when passing through the liquid crystal layer 18 is small. The scattering characteristics change due to the lengthening. That is, if the incident angle of the light beam incident on the PD liquid crystal display device 1Z differs depending on the location, the image quality of the projected image becomes non-uniform.
On the other hand, in order to reduce the radius of curvature of the concave surface of the concave lens 172, it is necessary to make convergent light having a large convergence angle incident on the PD liquid crystal display device 1Z or to increase the effective diameter of the projection lens 13D.

The former has a problem that the image quality of the projected image becomes non-uniform because the image quality is not uniform depending on the location on the PD liquid crystal display device 1Z, and the latter has a problem that the projection lens 13D becomes large and the cost increases. When the incident angle dependence of the scattering characteristics of the PD liquid crystal display device 1Z is large, as shown in FIG.
By combining the positive lens 171 with the concave lens 172,
Since almost parallel light can be made incident on the PD liquid crystal display device 1Z without increasing the size of the projection lens 13D, it is easy to ensure image quality uniformity of the projected image.

FIG. 29 shows an example in which a prism 231 is used in a color separation / color synthesis optical system. Since the configuration of the prism 231 in FIG. 29 is employed in the CCD part of the professional video camera, the description is omitted here. 233
Is a field lens. Prism 231 in FIG.
Has a three-part configuration of 232r, 232g, and 232b, and has a configuration in which the liquid crystal display device 1Z is OC (optically coupled). The liquid crystal display device 1 </ b> Z and the prism 231 are optically coupled by the optical coupling layer 34, and the light absorbing film 34 is formed or arranged on the invalid surface of the prism 231.

[0209]

According to the reflection type liquid crystal display device of the present invention, a cooling device composed of a Peltier element group, a radiation fin and the like is brought into close contact with the back surface of the reflection plate to pump heat generated in the liquid crystal panel to the outside. can do. Alternatively, the amount of heat pumped from the low temperature (liquid crystal panel) side to the high temperature (radiation fin) side is controlled by controlling the current value supplied to the cooling module. Therefore, the temperature of the liquid crystal panel can be controlled and the performance of the liquid crystal panel itself can be maintained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a liquid crystal display device of the present invention.

FIG. 2 is a diagram illustrating the principle of a polymer-dispersed liquid crystal.

FIG. 3 is an explanatory diagram of a liquid crystal display device of the present invention.

FIG. 4 is a graph showing a relationship between a luminance ratio and a relative substrate thickness.

FIG. 5 is an explanatory diagram of a liquid crystal display device of the present invention.

FIG. 6 is a diagram illustrating the principle of a cooling device in a liquid crystal display device according to the present invention.

FIG. 7 is a diagram illustrating the principle of a cooling device in a liquid crystal display device according to the present invention.

FIG. 8 is an explanatory diagram of a cooling device in the liquid crystal display device of the present invention.

FIG. 9 is an explanatory diagram of a cooling device in the liquid crystal display device of the present invention.

FIG. 10 is an explanatory diagram of a cooling device in the liquid crystal display device of the present invention.

FIG. 11 is an explanatory diagram of a cooling device in a liquid crystal display device of the present invention.

FIG. 12 is an explanatory diagram of a cooling device in a liquid crystal display device of the present invention.

FIG. 13 is a graph showing the relationship between thermal resistance and air flow rate.

FIG. 14 is an explanatory diagram of a cooling device in the liquid crystal display device of the present invention.

FIG. 15 is an explanatory diagram of a liquid crystal display device according to another embodiment of the present invention.

FIG. 16 is an explanatory diagram of a liquid crystal display device according to another embodiment of the present invention.

FIG. 17 is an explanatory diagram of a driving method of a liquid crystal display device of the present invention.

FIG. 18 is an explanatory diagram of a driving method of a liquid crystal display device of the present invention.

FIG. 19 is a configuration diagram of a projection display device of the present invention.

FIG. 20 is a configuration diagram of a projection display device of the present invention.

FIG. 21 is a configuration diagram of a projection display device according to another embodiment of the present invention.

FIG. 22 is an explanatory diagram of a projection display device according to another embodiment of the present invention.

FIG. 23 is a configuration diagram of a projection display device according to another embodiment of the present invention.

FIG. 24 is an explanatory diagram of a lens array of the projection display device of the present invention.

FIG. 25 is an explanatory diagram of a lens array of the projection display device of the present invention.

FIG. 26 is an explanatory diagram of the aperture of the stop of the projection display device of the present invention.

FIG. 27 is an explanatory diagram of a lens array of the projection display device of the present invention.

FIG. 28 is an explanatory diagram of the aperture of the stop of the projection display device of the present invention.

FIG. 29 is a configuration diagram of a projection display device according to another embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 11 radiating fins 12 ceramic plate 13 light reflecting plate 14 array substrate 15 pixel electrode 16 back light shielding film 17 TFT 18 liquid crystal layer 19 front light shielding film 110 counter electrode 1A counter substrate 1B cooling module 1C small cooler 1C1 small cooling fan 1C2 blowing direction 31 transparent Substrate 32 Panel incoming side 33 Panel outgoing side 34 Light absorbing film 35 Optical coupling layer 36 Scattered light 37 Reflected light 38 Outgoing light 41 Heat absorbing plate 42 n N-type semiconductor 42 p P-type semiconductor 43 Heat sink 44 DC power supply 45 Peltier element pair 51 Copper electrode 52 Solder Layer 53 Control Current 61 Blow Direction 71 Lateral Leak Prevention Plate 72 Streamlined Fin 73 Wind Flow 81 Bead 82 Insulating Film 111 Clock Generation Circuit 112 Clock Pulse for Timing Control 113 Timing Control Circuit (for G Signal) 114 Timing Control Circuit (for R signal) 115 Timing control circuit (for B signal) 116 Driver circuit drive pulse (for G signal) 117 Driver circuit drive pulse (for R signal) 118 Driver circuit drive pulse (for B signal) 11Z Signal control system 12S Source drive circuit 12G Gate drive circuit 12L Liquid crystal display unit 12M Liquid crystal display module 131 Lamp 132 Concave mirror 133 UVIR cut filter (or cold mirror) 134 Planar mirror 135 Projection lens (rear lens group) 136 Illumination light 137 Optical axis 138 R reflection dichroic mirror 139 Flat mirror (or R reflection dichroic mirror) 13A G reflection dichroic mirror 13B Projection light 13C Projection lens (front lens group) 13D Projection lens 13E Screen 1Zr Liquid crystal display device (for R) 1Zg Liquid crystal display (for G) 1Zb Liquid crystal display (for B) 141 Aperture stop 151 Dichroic prism 152r Light separation layer (R reflection) 152b Light separation layer (B reflection) 153 Light coupling layer 154 Field lens 155 Light shielding film 161r R side radiation fin 161g G side radiation fin 161b B side radiation fin 171r Concave lens (for R) 171g Concave lens (for G) 171b Concave lens (for B) 172r Convex lens (for R) 172g Convex lens (for G) 172b Convex lens (for B) 173r Concave / convex lens group (for R) 173g Convex lens group (for G) 173b Convex lens group (for B) 174 UVIR cut filter 175 Input convergent lens 176 Input convergent lens array 177 Central convergent lens 178 Central convergent lens array 191 Secondary light emission Image 201 stop discrete aperture stop 221 discrete openings

Claims (20)

[Claims] 1. A first electrode substrate, a second electrode substrate including a reflective electrode having a light reflecting function and a heat absorbing function, and light sandwiched between the first electrode substrate and the second electrode substrate. A reflective liquid crystal display device comprising: a liquid crystal layer that forms an optical image as a change in a scattering state; and a heat radiating unit that is provided directly on the reflective electrode and radiates heat absorbed by the reflective electrode. . 2. A first electrode substrate on which a counter electrode is formed, a second electrode substrate on which pixels are formed in a matrix and including a reflective electrode having a light reflecting function and a heat absorbing function, and the first electrode A polymer-dispersed liquid crystal layer sandwiched between a substrate and a second electrode substrate; and a radiator provided directly on the reflective electrode and radiating heat absorbed by the reflective electrode. Reflective liquid crystal display device. 3. The ratio of the liquid crystal material in the polymer dispersed liquid crystal is 60 to 90%, the ordinary light refraction no of the liquid crystal material is 1.50 to 1.53, and the refractive index difference n is 0.15 to 0. 3. The reflective liquid crystal display device according to claim 2, wherein 4. A film having a higher specific resistance than the liquid crystal layer is provided between the liquid crystal layer and the first electrode substrate and between the liquid crystal layer and the second electrode substrate. The reflective liquid crystal display device according to claim 1. 5. A second electrode substrate having a first electrode substrate on which a counter electrode is formed, pixel electrodes arranged in a matrix, switching elements for switching the pixel electrodes, and a reflective film having a heat absorbing function. A transparent substrate having an optical coupling layer on one surface on the first electrode substrate side and an antireflection film on the other surface, and sandwiching between the first electrode substrate and the second electrode substrate. Liquid crystal layer, a light-shielding film formed between at least one of the switching element and the first electrode substrate and between the switching element and the reflection film, and for preventing light from entering the switching element;
A reflection type liquid crystal display device, comprising: a heat radiating unit provided directly on the reflection film to radiate heat absorbed by the reflection film. 6. A first electrode substrate on which pixel electrodes arranged in a matrix and switching elements for switching the pixel electrodes are formed; a second electrode substrate including a counter electrode and a reflective film having a heat absorbing function; A transparent substrate having an optical coupling layer on one surface on the first electrode substrate side and an antireflection film on the other surface, and being sandwiched between the first and second electrode substrates. A liquid crystal layer, a light shielding film formed on at least one of between the switching element and the first electrode substrate and between the switching element and the reflection film, and for preventing light from entering the switching element; A reflection type liquid crystal display device, comprising: a heat radiating unit provided directly on the reflection film to radiate heat absorbed by the reflection film. 7. An insulating film having a specific resistance higher than the specific resistance of the liquid crystal layer is formed on the surface of the counter electrode in contact with the liquid crystal layer. Reflective liquid crystal display device. 8. The reflection type liquid crystal display device according to claim 5, wherein the reflection film is a dielectric reflection film composed of a multilayer dielectric thin film. 9. The reflection type liquid crystal according to claim 1, wherein a film thickness holding means is provided between the first electrode substrate and the second electrode substrate. Display device. 10. The reflection type liquid crystal display device according to claim 9, wherein the film thickness holding means is a bead made of a material having high thermal conductivity. 11. The reflection type liquid crystal display device according to claim 1, wherein the heat radiating means comprises a cooling fan, a Peltier element group, and a heat radiating plate. 12. The reflection type liquid crystal display according to claim 1, wherein an optical element is attached to at least one of the first electrode substrate and the second electrode substrate. apparatus. 13. A light generating means, and a light separating means for separating light emitted by the light generating means into a first light path for red light, a second light path for green light, and a third light path for blue light. The first reflective polymer-dispersed liquid crystal display device according to claim 2, which modulates light in the first optical path, and modulates light in the second optical path. 3. The reflective polymer-dispersed liquid crystal display device of claim 1 and modulating light in said third optical path.
3. A reflection type polymer dispersed liquid crystal display device as described in 1), an optical path combining means for combining at least two optical paths among the first to third optical paths into one, and a modulation by the polymer dispersed liquid crystal display device. And projection means for projecting the light, wherein one of the first to third polymer-dispersed liquid crystal display devices is
A projection type display device connected to the optical path synthesizing unit via an optical coupling layer, wherein a light absorbing unit is arranged in a region where light effective for display does not pass in the optical path synthesizing unit. . 14. The projection type display device according to claim 13, wherein the combining means is a prism-shaped mirror. 15. A light-generating means having a luminous body, the reflective liquid crystal display device according to claim 2, and a secondary for forming a secondary luminous body by condensing and converging light emitted by said luminous body. A luminous body forming means, a projecting means for projecting an optical image formed by the light modulating means, a first diaphragm means arranged on a light incident side of the light modulating means, and a light emitting side of the light modulating means. A second stop arranged, wherein the light modulating means is illuminated by light emitted from the secondary light emitter, and the first stop and the second stop are substantially conjugated. Wherein the first aperture means has an opening shape for selectively transmitting light mainly passing through the effective area of the secondary luminous body, and the second aperture means is a light modulation layer of the light modulation means. Selectively transmits light passing through the first stop in a light transmitting state. A projection display device characterized by having an opening shape. 16. The reflective liquid crystal display device according to claim 13, wherein a film thickness holding means is provided between the first electrode substrate and the second electrode substrate. 3. The projection display device according to 1. 17. The projection type display device according to claim 15, wherein the first aperture means is arranged near the secondary luminous body. 18. A secondary illuminant forming means for forming a plurality of secondary illuminants discretely located, a first aperture means and a second
16. The projection display device according to claim 15, wherein at least one of the aperture means has a plurality of openings that are discretely located. 19. The projection type display device according to claim 13, wherein an F number of the projection means is approximately 5 to 9. 20. When the effective diagonal length of the liquid crystal display device is d (inch) and the arc length of the lamp of the light generating means is a (mm), the relationship a (mm) ≦ d (inch) is satisfied. 20. The projection type display device according to claim 13, wherein: