JP3412626B2 - Liquid crystal display panel, viewfinder and projection display - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a display panel for displaying a touch panel or a television image, etc., and a display device for enlarging and projecting an image displayed on the display panel on a screen by using the display panel as a light valve.
It also relates to a device such as a display device (hereinafter referred to as a viewfinder) that uses the display panel as a monitor of an image captured by a video camera.

[0002]

2. Description of the Related Art Since a liquid crystal display panel has many features such as light weight and thinness as compared with a CRT, research and development have been actively conducted. Further, in recent years, it has been used as a display portion of a viewfinder of a pocket television or a video camera. However, there are many problems such as difficulty in increasing the screen size. Therefore, in recent years, attention has been focused on a projection type display device which obtains a large-screen display image by enlarging and projecting a display image on a small display panel using a projection lens or the like. Incidentally, a twisted nematic (hereinafter referred to as TN) display panel utilizing the optical rotation characteristic of liquid crystal is currently used in a projection type display device and a viewfinder which are commercialized.

A conventional display panel will be described below. However, the unnecessary parts are omitted in the explanation, and
It is drawn as a model to make the drawing easier to see. The above also applies to the subsequent drawings.

FIG. 46 is a sectional view of a conventional display panel. Array substrate 12 on which thin film transistors (hereinafter referred to as TFTs) 14 and the like, counter substrate 11 and 4 to 6 μm
And the TN liquid crystal layer 383 is injected between the substrates. The periphery of the display area is sealed with a sealing resin (not shown). 381 is a black matrix (hereinafter referred to as BM) formed of a metal material such as chromium, 13 is a counter electrode formed of a transparent material such as ITO, 15 is a pixel electrode, and 382 is an alignment film.

An alignment film 382 is formed on the pixel electrode 15 and the counter electrode 13, and the alignment film 382 has a T film.
A rubbing treatment for aligning the liquid crystal molecules of the N liquid crystal layer 383 is performed. A polarizing plate 384 is attached to the counter substrate 11 and the array substrate 12.

Here, a method of manufacturing the TN display panel will be briefly described. First, the alignment films 382a and 382b are applied to the array substrate 12 and the counter substrate 11, respectively, and subjected to alignment treatment by a rubbing process. Then, a sealing resin (not shown) is applied to the peripheral portion of the array substrate 12 leaving the injection port of the TN liquid crystal layer 383. Moreover, transparent glass beads or beads made of resin are sprayed on the counter substrate 11 to obtain a uniform liquid crystal film thickness. Next, the counter substrate 11 and the array substrate 12 are bonded together. Then, the sealing resin is cured by heating. Next, the bonded substrates are placed in a vacuum chamber, the gap between the array substrate 12 and the counter substrate 11 is evacuated, and then the liquid crystal injection port is immersed in the TN liquid crystal. After that, when the vacuum in the vacuum chamber is broken, the liquid crystal is injected into the gap through the injection port. Finally, the injection port is sealed and completed.

FIG. 15 is a plan view of a display panel module having a display panel attached to a chassis or the like and a sectional view taken along line HH '. A printed circuit board 162, on which a connector 163, an electric field capacitor (not shown) and the like are mounted, is attached to a chassis 161 formed by processing a stainless steel plate into a metal plate. The central portion of the printed board 162 is punched out, and the display panel is embedded in the punched portion.
Thin copper wiring (not shown) for transmitting electric signals and the like from the terminals of the connector 163 is formed on the printed board 162. Further, a thin film wiring for transmitting the electric signal is also formed on the display panel. One end of the thin copper wiring and one end of the thin film wiring are connected by a thin wire (bonding wire) of aluminum (Al).

A light-shielding pattern 164 is formed in a V-shape outside the display area of the display panel. In FIG. 15, the light shielding pattern is shown by a dotted line. Shading pattern 164 of FIG.
47 is a sectional view taken along line JJ ′ and KK ′ in the vicinity of FIG.
Shown in. The light-shielding pattern 164 is made of chromium (Cr) and has a film thickness of about 1000 Å.
It is formed on the counter electrode 13 of the counter substrate 11. 2
Reference numeral 1 is a source signal line.

The light-shielding patterns 164 and BM are formed of Cr because the film thickness is relatively thin and a good light-shielding effect is obtained. In the TN display panel, it is necessary to subject the alignment film 382 to an alignment treatment in order to align the liquid crystal molecules.
Since the alignment treatment is performed by rubbing (rubbing) the pixel electrodes 15, when the film thickness of the BM 381 or the like increases,
Unevenness becomes large on the counter substrate 11 and the array substrate 12, and good alignment processing cannot be performed.

The reason why the light-shielding pattern 164 is formed outside the display area will be briefly described. Although there are no pixels outside the display area, source signal lines 21 and the like are formed to transmit signals to the display area. Source signal line 2
Since 1 is a metal thin film, it shields light. However, the light incident between the source signal lines is transmitted because there is no light shield between the signal lines. Since only the light in the display area needs to be transmitted (modulated by the pixels), the transmitted light from outside the display area is useless, and the light makes the displayed image difficult to see. The transmitted light is blocked by the chassis 1
Perform at 61. Since the chassis 161 is a metal plate such as stainless steel, it does not transmit light. The chassis 161 has a hole at its center, and the chassis 161 is arranged so that the hole and the display area of the display panel coincide with each other.

The display panel has a very high dimensional accuracy because it is manufactured by a semiconductor process, but the dimensional accuracy is low because the chassis 161 is manufactured by machining. Further, the accuracy with which the display panel is attached to the chassis 161 is low. Therefore, if the hole diameter of the chassis 161 is large, light leakage occurs from the peripheral portion of the display area, that is, between the source signal lines. If the hole diameter is small, a part of the display area is shielded by the chassis 161. Further, if the mounting position shifts, light leakage occurs from one end, and the other end blocks part of the display area.
Therefore, the light shielding pattern 164 is formed with a width of about 2 mm,
The hole diameter of the chassis 161 is made larger than the display area. Then, the light-shielding pattern 164 can be positioned in the clearance between the display area and the hole diameter of the chassis, and even if the mounting position of the panel shifts by 2 mm at the worst, light leakage does not occur from the outside of the display area. Further, the display area is not shielded from light.

[0012]

In the display panel using the TN liquid crystal, it is necessary to make the incident light linearly polarized by using the polarizing plate 384a. In addition, since the light modulated by the liquid crystal display panel is also detected on the exit side of the display panel, a polarizing plate 384 is provided.
It is necessary to arrange b. That is, a polarizing plate 384a for converting light into linearly polarized light is provided before and after the TN liquid crystal display panel.
It is necessary to dispose two polarizing plates (hereinafter referred to as a polarizer) and a polarizing plate 384b (hereinafter referred to as an analyzer) for detecting the modulated light. When the pixel aperture ratio of the liquid crystal display panel is 100%, the amount of light incident on the polarizer 384a is 10%.
If 0, the amount of light emitted from the polarizer 384a is 40%,
Since the transmittance of the display panel is 80% and the transmittance of the analyzer 384b is 80%, the overall transmittance is 0.4 ×.
0.8 × 0.8 = about 25%, and only 25% of light can be effectively used. Therefore, the TN display panel can realize only low-luminance image display.

Most of the light lost by the polarizing plate 384 is absorbed by the polarizing plate 384 and converted into heat. The heat heats the display panel by the polarizing plate 384 itself and radiant heat. In the case of a projection display device, the amount of light incident on the polarizing plate 384 is tens of thousands of lux or more. Therefore, when the TN display panel is used as the light valve of the projection type display device,
The polarizing plate 384, the panel, and the like are in a high temperature state, which causes remarkable performance deterioration in a short period of time.

Further, the TN display panel needs to be coated with an alignment film 382 and rubbed. The rubbing process 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 display panel used in a projection type display device is as large as 300,000 pixels or more, and accordingly, the pixel size tends to be miniaturized. Pixel miniaturization is due to signal lines and TF
Many irregularities due to T14 or the like are formed per unit area. Obviously, the rubbing treatment cannot be performed well due to the unevenness. Further, the miniaturization of the pixel size increases the formation area of the TFT 14 and the signal line occupying one pixel, and reduces the pixel aperture ratio. As an example,
When 350,000 pixels are formed on a 3-inch diagonal display panel,
The pixel aperture ratio is about 30%. There is a predicted value of less than 10% when 1.5 million pixels are formed. The reduction of the pixel aperture ratio is not limited to the reduction of the brightness of the display image, and the display panel is further heated by the light emitted to the portion other than the incident light opening portion, which accelerates the performance deterioration of the TN display panel.

The TN liquid crystal performs optical modulation by changing the alignment state of the liquid crystal by the voltage applied to the pixel electrode 15. TN
Polarizing plates are arranged on the entrance side and the exit side of the display panel, respectively, and the polarization axes of the polarizer 384a and the analyzer 384b are orthogonal to each other. Generally, the TN display panel is used in a mode (NW mode) in which black display can be performed in a voltage applied state.

The display image on the display panel in the NW mode has good color reproducibility, but a problem is light leakage from the peripheral portion of the pixel. This is because the liquid crystal molecules are not oriented in the regular direction but are oriented in the opposite direction. This orientation state is called an inverted chilled domain. This occurs because the rising directions of the liquid crystal molecules are partially reversed by the electric field generated between the pixel electrode 15 and the source signal line 21. In the portion where the rising directions of the liquid crystal molecules are reversed, the light passes through the analyzer 384b on the emission surface even though the voltage is applied. That is, light leakage occurs. Light leakage does not occur in the normal rising direction of the liquid crystal.

As a method of preventing light leakage, there is a method of widening the width of the BM 381 formed on the counter electrode, but this also reduces the pixel closing area and lowers the display brightness, which is effective. Not a method.

The display panel using the TN liquid crystal as described below needs to use the polarizing plate 384. Further, since light leakage is likely to occur in the pixel peripheral portion, the BM must be thickened. Therefore, the light utilization rate is poor and the display brightness is low. The light applied to the BM heats the display panel, raising the panel temperature and shortening the life of the panel.

Similarly, the projection type display device using the TN display panel as a light valve also has a low light utilization rate and the screen brightness of the projected image is low. Therefore, a projection type display device using a polymer dispersed (PD) display panel without using the polarizing plate 384 has been proposed. As an example, JP-A-3-94
The one described in Japanese Patent No. 225 publication is mentioned. A PD display panel as a light valve used in a projection display device performs light modulation by scattering or transmitting incident light.

The structure of the PD display panel is shown in FIG.
The polarizing plate 384 is removed from the N liquid crystal display panel, and
An example is a configuration in which the alignment film 382 is not formed. As a matter of course, PD liquid crystal is used for the liquid crystal layer.

Operation of PD display panel FIG.
A brief description will be given using (a) and (b). FIG. 34
(A), (b) is explanatory drawing of operation | movement of PD display panel. In FIGS. 34A and 34B, a water droplet liquid crystal (hereinafter, referred to as water droplet liquid crystal 331) is dispersed in the polymer 332. The pixel electrode 15 has a TFT (not shown)
Etc. are connected, and the pixel electrode 15 is turned on / off by turning on / off the TFT.
A voltage is applied to the pixel electrode 15 to change the liquid crystal alignment direction on the pixel electrode 15 to modulate light. When no voltage is applied as shown in FIG.
31 is oriented in an irregular direction. In this state, a difference in refractive index occurs between the polymer 332 and the water droplet liquid crystal 331, and incident light is scattered.

Here, as shown in FIG. 34B, when a voltage is applied to the pixel electrode 15, the directions of the liquid crystal molecules are aligned. When the refractive index when the liquid crystal molecules are aligned in a certain direction is matched with the refractive index of the polymer 332 in advance, incident light is emitted from the array substrate 12 without being scattered.

Here, a method of manufacturing the PD display panel will be described. As the polymer 332, a photocurable resin,
In particular, UV curable resin that is cured by UV (hereinafter UV
Resin) is usually used. Array substrate 12 and counter substrate 1
1 is held at a constant interval. Fine beads are often used as the holding means. The PD display panel basically does not require the formation of the alignment film 382. A solution (hereinafter referred to as a mixed solution) in which an uncured UV resin component and a liquid crystal component are mixed is injected between the array substrate 12 and the counter substrate 11. Next, the mixed solution is irradiated with ultraviolet light. Then, the UV resin of the mixed solution is cured, and the resin component and the liquid crystal component are phase-separated. When the amount of liquid crystal is small, the liquid crystal becomes a water drop liquid crystal 331 as shown in FIG. 34, and when the amount of liquid crystal is large,
The water droplet liquid crystals 331 are connected continuously.

In the uncured UV resin, the portion irradiated with the ultraviolet light is cured and the resin component and the liquid crystal component are phase-separated, but the resin is not cured in the portion not irradiated with the light.
In the structure of the display panel of FIG. 46, the TN liquid crystal layer 383
Consider the case where a mixed solution is injected instead of. BM38
Since 1 is formed of a metal thin film, it blocks ultraviolet light. Further, since the TFT 14 and the like are also formed of a metal thin film or the like, they block ultraviolet light. U in area a under BM381
Even if the V resin is irradiated with ultraviolet light from the array substrate 12 side,
Irradiation with ultraviolet light from the side of the counter substrate 11 does not cure.
The BM381 blocks the above light when it is irradiated with UV light from the A direction, and TF when it is irradiated with UV light from the B direction.
This is because T14 blocks the light.

The uncured UV resin adversely affects the reliability and life of the PD display panel. The composition of the liquid crystal is likely to change during the operation of the display panel, and the liquid crystal layer and the counter substrate 11 are easily separated.

With the BM 381 and the like, it is difficult to set ultraviolet irradiation conditions when manufacturing a display panel. At the time of manufacturing, a mixed solution in which liquid crystal and uncured UV resin are mixed at a predetermined ratio is injected between the array substrate 12 and the counter substrate 11 and irradiated with ultraviolet light, the liquid crystal in the peripheral portion of the pixel electrode 15 (a portion close to BM). The average particle size of, or the average pore size of the polymer network tends to be large. It is considered that this is because the BM 381 absorbs ultraviolet rays and is heated, so that the temperature of the resin around the BM is extremely increased, and the conditions for phase separation of the liquid crystal component and the resin component are changed extremely. To be Of course, the scattering characteristics also deteriorate. When the BM381 is formed as described above, the average particle size of the liquid crystal on the pixel electrode or the average pore size of the polymer network tends to change due to slight temperature changes during manufacture and the irradiation intensity of ultraviolet rays. , Its manufacturing condition margin is narrow. Therefore, it is difficult to stably manufacture PD display panels having the same characteristics.

When the PD display panel is used as a light valve of a projection type display device, if the uncured UV resin described above remains in the PD display panel, the performance is significantly deteriorated. It is considered that this is because light of tens of thousands of lux or more is incident on the display panel in the projection type display device, and optical stress and heat stress are large.

As described above, conventionally, since the TN display panel uses the polarizing plate, the light utilization efficiency is poor, and high brightness display cannot be realized. Further, although the PD display panel can realize high-brightness display, it is not practically used because the uncured UV resin remains in the conventional structure and the stability is poor. In addition, the manufacturing condition margin is narrow, and PD with high scattering characteristics
It was difficult to obtain a display panel stably.

The present invention provides a display panel having high brightness display, good stability and no change over time, and a projection type display device using the same as a light valve.

[0030]

First, a liquid crystal display panel according to the present invention has a first structure in which pixel electrodes are arranged in a matrix.
And the substrate, a second substrate on which the common electrode is formed, a liquid crystal layer sandwiched between the first substrate and the second substrate, between the pixel electrode in contact next <br/> The dielectric columns are disposed, the dielectric constant of the dielectric columns is smaller than the dielectric constant of the liquid crystal layer, and the height of the dielectric columns is substantially equal to the film thickness of the liquid crystal layer. The dielectric pillar is a dielectric multilayer film.
Characterized in that there.

Secondly, in the liquid crystal display panel of the present invention, the first substrate on which the pixel electrodes are arranged in a matrix, the second substrate on which the counter electrode is formed, the first substrate and the second substrate.
Comprising a liquid crystal layer sandwiched, and the first dielectric pillars formed on the first substrate and a second dielectric pillars formed in the second substrate between the substrate The height obtained by adding the height of the first dielectric pillar and the height of the second dielectric pillar is substantially equal to the film thickness of the liquid crystal layer, and the dielectric constant of the dielectric pillar is
The rather smaller than the dielectric constant of the liquid crystal layer, the dielectric pillars, induced
It is characterized by being an electric multilayer film .

Thirdly, in the liquid crystal display panel of the present invention, the first substrate on which the reflective electrodes are arranged in a matrix, the second substrate on which the counter electrodes are formed, the first substrate and the second substrate.
A liquid crystal layer sandwiched between the substrates, includes a dielectric film formed between the reflective electrode in contact next to the dielectric constant of the dielectric film than the dielectric constant of the liquid crystal layer rather small, the induction
The electric pole is characterized by being a dielectric multilayer film .

Fourthly , the liquid crystal display panel of the present invention has a pixel
Opposite the first substrate on which the electrodes are arranged in a matrix
A second substrate having electrodes formed thereon, the first substrate and the second substrate
The liquid crystal layer sandwiched between the substrate and the adjacent pixel
A dielectric film disposed between electrodes, the dielectric film comprising:
The dielectric constant of is smaller than the dielectric constant of the liquid crystal layer, and the dielectric film is a dielectric multilayer film.

Fifth, the projection type display device of the present invention is claimed.
The liquid crystal display panel according to any one of claims 1 to 4.
And the arc discharge lamp, the arc discharge lamp radiates
An optical system for guiding the generated light to the liquid crystal display panel, and the liquid crystal
A projection lens that magnifies and projects the light modulated by the display panel
It is characterized by having.

Sixth, the viewfinder of the present invention is a contract
The liquid crystal display panel according to any one of claims 1 to 4.
An illuminating means for illuminating the liquid crystal display panel;
The light modulated by the crystal display panel is magnified and visible to the observer.
And a magnifying lens for controlling the light intensity.

Seventh, the viewfinder of the present invention is a contract
The liquid crystal display panel according to any one of claims 1 to 4.
And the light generating means and the light emitted by the light generating means
The first laser light is converted into line light and illuminates the liquid crystal display panel.
And the light modulated by the liquid crystal display panel is magnified and viewed.
To have a magnifying lens that makes it visible to the observer.
Characterize.

[0037]

[0038]

[0039]

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The display panel of the present invention will be described below with reference to the drawings. It should be noted that each drawing is drawn as a model in order to facilitate description or understanding. Therefore, the physical thickness or shape in the drawings does not always match the actual display panel. Also,
Parts unnecessary for explanation are omitted.

FIG. 1 is a sectional view of the display panel of the present invention. The counter substrate 11 and the array substrate 12 are glass substrates, have a thickness of 1.1 mm, and the glass substrate has a refractive index n of 1.52. On the array substrate 12, a pixel electrode 15 made of ITO, a TFT 14 as a switching element for applying a signal to the pixel electrode 15, various signal lines (not shown), and the like are formed. As the switching element, in addition to the TFT, a ring diode, MI
It may be a two-terminal element such as M, a varicap, a thyristor element, or the like.

In the present specification and claims, a substrate (for example, each substrate 11, 12, 214, 21) is used.
5) is not limited to the glass substrate. For example, a plate made of a resin such as acrylic or polycarbonate may be used. Further, a film or sheet made of the above resin or the like may be used.

A light shielding film 18 is formed on the TFT 14. The light shielding film 18 mainly prevents the light scattered by the liquid crystal layer 17 from entering the semiconductor layer of the TFT 14. When light enters the semiconductor layer, the TFT does not turn off,
Alternatively, a photoconductor phenomenon (hereinafter, referred to as photocon) in which the off resistance of the TFT is lowered occurs. An example of a material for forming the light-shielding film is an acrylic resin in which carbon is dispersed. In addition, an optimal mixture of various primary color pigments (red, green, blue, cyan, magenta, and yellow pigments), an insulating thin film made of SiO ₂ or the like on the TFT, and a metal as a light-shielding film on the insulating thin film. A method of patterning and forming a thin film is also exemplified. There is also a method in which amorphous silicon is vapor-deposited thickly to form a light-shielding film. Also, TF
T14 preferably employs a stagger structure in which a semiconductor layer is formed under the gate.

In the PD display panel, it is preferable that the TFT is formed by the polysilicon technique so that photocon is less likely to occur. The polysilicon technology includes a high temperature polysilicon technology which is a semiconductor technology for producing a normal IC, and 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 to form the TFT by a low-temperature polysilicon technology that can incorporate a drive circuit and can manufacture a panel at low cost. The TFT formed by the above technique is much less likely to cause the photoconductor phenomenon than the TFT formed by the amorphous silicon technique. Therefore, it is most suitable for a polymer dispersed liquid crystal display panel that performs light modulation by scattering-transmission.

When the light-shielding film 18 is made of resin, the light-absorbing material contained in the resin may be any material as long as it has high electric insulation and does not adversely affect the liquid crystal layer 17. For example, a black dye or pigment dispersed in resin may be used, or gelatin or casein may be dyed with a black acid dye like a color filter. As an example of the black dye, it is possible to use a single fluoran dye that turns black, and it is also possible to use a color arrangement black in which a green dye and a red dye are mixed.

Although the above materials are all black materials,
When the display panel of the present invention is used as a light valve of a projection type display device, it is not limited to this. The projection type display device is one in which three display panels each modulate light of three colors of R, G and B. The light shielding film 18 of the display panel that modulates the R light may absorb the R light. That is, in order to absorb a specific wavelength, for example, a light absorbing material for a color filter may be used after being improved so as to obtain a desired light absorbing characteristic. Basically, similar to the black absorbing material described above, dyeing a natural resin with a dye,
A material in which a dye is dispersed in a synthetic resin can be used. The range of dye selection is wider than black dye,
Azo dye, anthraquinone dye, phthalocyanine dye,
A suitable one of triphenylmethane dyes or the like, or a combination of two or more thereof may be used. Also,
As a measure against impurities in the light absorption film, it is possible to remove the alkali metal in the dye (pigment).

Many black dyes adversely affect the liquid crystal layer 17. Therefore, its use is not preferable. Therefore, it is preferable to employ a dye capable of absorbing a specific wavelength as a dye contained in the light absorbing thin film as described above.

It is easy to adopt in a projection type display device using three display panels for R light, B light and G light as light valves. In other words, for the color of the modulated light,
A dye having a complementary color relationship may be contained in the light shielding film 18 which is a light absorbing thin film. The complementary color relationship is, for example, yellow for B light. The light absorbing thin film colored yellow is B
Absorbs light. Therefore, the display panel that modulates the B light forms the yellow light shielding film 18.

If the light shielding film 18 is made of resin, the liquid crystal layer 1
Adhesion between 7 and the array substrate 12 is improved. This is because the polymer dispersed liquid crystal layer 17 contains a resin component. Peeling easily occurs between the liquid crystal layer 17 and the ITO forming the pixel electrode 15 and the like. Light-shielding film 1 made of resin for the TFT 14, etc.
8 is formed, the light-shielding film 18 does not act as a buffer layer and peels off. From this point, it is preferable to employ a light-shielding film made of resin.

A PD liquid crystal layer 17 is sandwiched between the counter electrode 13 and the pixel electrode 15. The liquid crystal material used in the display panel of the present invention is preferably a nematic liquid crystal, a smectic liquid crystal, or a cholesteric liquid crystal, which is single or 2
It may be a mixture containing more than one kind of liquid crystal compound or a substance other than the liquid crystal compound.

Among the above-mentioned liquid crystal materials, a cyanobiphenyl nematic liquid crystal having a relatively large difference between the extraordinary light refractive index n _e and the ordinary light refractive index n _o , or a fluorine-based or chlorine stable with time. The nematic liquid crystal of the system is preferable, and among them, the nematic liquid crystal of the chloro type is the most preferable because it has a good scattering property and hardly changes with time.

As the polymer matrix material, a transparent polymer is preferable, and as the polymer, a photo-curing type resin is used in terms of easiness of manufacturing process, separation from the liquid crystal layer and the like. As a specific example, an ultraviolet curable acrylic resin is exemplified, and a resin containing an acrylic monomer or an acrylic oligomer which is polymerized and cured by ultraviolet irradiation is particularly preferable. Above all, a photocurable acrylic resin having a fluorine group is preferable because it can form the light modulation liquid crystal layer 17 having good scattering characteristics and is less likely to change over time.

[0053] Further, the liquid crystal material, the ordinary refractive index n _o is preferable to use those from 1.49 1.54, among others, ordinary refractive index n _o those from 1.50 1.53 Is preferable to use. Further, it is preferable to use one having a refractive index difference Δn of 0.15 or more. n _o, △
When n becomes large, heat resistance and light resistance deteriorate. n _o, △ n
If the value is small, the heat resistance and the light resistance are improved, but the scattering characteristics are lowered and the display contrast is not sufficient.

From the above, as the constituent material of the light modulating liquid crystal layer 17, the ordinary refractive index n _o is 1.50 to 1.53,
In addition, it is preferable to use a chloro-based nematic liquid crystal having Δn of 0.15 or more and 0.30 or less and employ a photocurable acrylic resin having a fluorine group as a resin material.

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

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

A polymerization initiator may be used in order to carry out the polymerization rapidly, and as an example of this, 2-hydroxy-2 is used.
-Methyl-1-phenylpropan-1-one ("Darocur 1173" manufactured by Merck & Co., Inc.), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1
-ON (“Darocur 1116” manufactured by Merck & Co., Inc.), 1-vidroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by Ciba-Geigy), 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 in combination as optional components.

The refractive index n _p when the resin material is cured
And the ordinary refractive index n _o 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 oriented in one direction, and the refractive index of the liquid crystal layer becomes n _o . Therefore, the refractive index n _{p of the} resin matches, and the liquid crystal layer is in a light transmitting state. If the difference between the refractive indexes n _p and n _o is large, the liquid crystal layer does not become completely transparent even when a voltage is applied to the liquid crystal layer, and the display brightness decreases. Refractive index difference between the refractive index n _p and n _o is preferably within 0.1, more within 0.05 are preferred.

Although the proportion of the liquid crystal material in the PD liquid crystal layer is not specified here, it is generally about 20 to 90% by weight, preferably about 50 to 85% by weight. If it is 20% by weight or less, the amount of liquid crystal droplets is small and the scattering effect is poor. On the other hand, when it is 90% by weight or more, the polymer and the liquid crystal tend to be phase-separated into upper and lower two layers, the ratio of the interface becomes small, and the scattering property is deteriorated. The structure of the polymer-dispersed liquid crystal layer changes depending on the liquid crystal fraction, and at about 50% by weight or less, the liquid crystal droplets exist as independent droplets.
When it is 50% by weight or more, the polymer and the liquid crystal form a continuous layer intricately intermingled with each other.

The average particle diameter of the water-drop liquid crystal or the average pore diameter of the polymer network is 0.5 μm or more and 3.0 μm.
The following is preferable. Above all, 0.8 μm or more 2
μm or less is preferable. When the light modulated by the PD display panel has a short wavelength (for example, B light), it is small, and when it has a long wavelength (for example, R light), it is large. When the average particle size of the water-drop liquid crystal or the average pore size of the polymer network is large, the voltage for making the liquid crystal in a transparent state is low, but the scattering property is low. When it is small, the scattering property is improved, but the voltage for making it in the transmissive state is high.

When a polymer-dispersed liquid crystal is used in the display panel of the present invention, the average particle diameter of the water-drop liquid crystal of the display panel that modulates blue light or the average pore diameter of the polymer network is that of the display panel that modulates red light. Is smaller than.

The polymer-dispersed liquid crystal referred to in the present invention is a liquid crystal in which liquid crystal is dispersed in a resin (see FIG. 34), the resin is in a sponge form (polymer network), and the liquid crystal is filled between the sponge forms. The above-mentioned ones are applicable, and in addition, Japanese Patent Application Laid-Open No. 6-208126 and Japanese Patent Application Laid-Open No. 6-202085.
It also includes that the resin as disclosed in the publication is layered. Further, it also includes one in which liquid crystal is enclosed in a capsule-shaped accommodating medium as in Japanese Patent Publication No. 3-52843. Further, the liquid crystal or resin containing a dichroic or polychromatic dye is also included.

The thickness of the liquid crystal layer 17 is preferably in the range of 5 to 20 μm, more preferably 8 to 15 μm. If the film thickness is thin, the scattering characteristics are poor and the contrast cannot be obtained. On the contrary, if the film thickness is high, high voltage driving must be performed, and the gate drive circuit that generates a signal for turning the TFT 14 on and off to the gate signal line, and the source signal line 21 It becomes difficult to design a source drive circuit that applies a signal.

For controlling the film thickness of the liquid crystal layer 17, black glass beads or black glass fibers, or
Use 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 absorption property and are hard, so that the number of them dispersed in the liquid crystal layer can be small.

Although the beads and fibers are black in the above description, the present invention is not limited to this when the display panel of the present invention is used as a light valve of a projection type display device. The projection type display device has three display panels R,
The light of three colors of G and B is modulated respectively. The black beads 19 and the like used for the display panel that modulates R light are R
It should absorb light. That is, the black beads 19 containing a dye having a complementary color relationship with the color of light to be modulated may be used.

The liquid crystal layer 17 scatters incident light (displays black) when no voltage is applied. When transparent beads are used, light is leaked from the beads even in black display, and the display contrast is lowered. Like the display panel of the present invention, if black glass beads or black glass fibers are used, light leakage does not occur and good display contrast can be realized.

On the other hand, the counter electrode 13 made of ITO is formed on the counter substrate 11, and the dielectric multilayer film 16 is formed on the counter electrode 13. Since the dielectric multilayer film 16 has a thin thickness of 1.5 μm or more, it is not so preferable to form the counter electrode 13 on the dielectric multilayer film 16. This is because the counter electrode 13 is electrically cut at the edge of the dielectric multilayer film 16. The dielectric multilayer film 16 includes a low refractive index dielectric thin film having a refractive index of 1.7 or less (hereinafter referred to as a low refractive index thin film) and a high refractive index dielectric thin film having a refractive index of 1.8 or more (hereinafter, high refractive index). (Refer to the refraction thin film) is laminated alternately and in multiple layers. As a low-refraction thin film, silicon oxide (SiO 2
₂ , refractive index n = 1.46) or magnesium fluoride (MgF ₂ , refractive index n = 1.39). Hafnium oxide (HfO ₂ , refractive index n =
2.0) or zirconium oxide (ZrO ₂ , refractive index n
= 2.05), tantalum oxide (Ta ₂ O ₅ , refractive index n =
1.95) is exemplified, and among them, it is preferable to use HfO ₂ and SiO ₂ which have a small light absorption rate in the ultraviolet light region. ZrO ₂ is slightly inferior to HfO ₂ in ultraviolet light transmittance, and MgO ₂ may be cracked. The multilayer structure of SiO ₂ and HfO ₂ is less likely to cause cracks and has a good ultraviolet transmittance.

The physical film thickness d of one layer of the low-refractive-index thin film or the high-refractive-index thin film is approximately d = λ / (4 · n) (where λ is the design dominant wavelength nm). Designed main wavelength is λ = 620 nm when the dielectric multilayer thin film is designed to reflect R light, λ = 540 nm when it is designed to reflect G light, and is designed to reflect B light. Is about λ = 460 nm. The λ is determined in accordance with the wavelength of light modulated by the display panel and the intensity distribution with respect to the wavelength of light.

When actually designing, a sharp transmission band or a reflection band is generated at a specific wavelength, so that it is necessary to adjust the optical film thickness of each layer. An example of the design of the dielectric multilayer film 16 is shown in (Table 1), (Table 2) and (Table 3) below, and the characteristic diagrams thereof are shown in FIGS. 35, 36 and 37.

[0070]

[Table 1]

[0071]

[Table 2]

[0072]

[Table 3]

In each table, ITO is the counter electrode 1
It is 3. The refractive index n of ITO is 2.0. The ITO thin film (counter electrode) 13 has an optimal film thickness corresponding to the wavelength of light incident on the display panel. As an example, the optical film thickness of the ITO thin film (counter electrode) 13 (d.
n) is approximately λ / 2. If it is a multiple of approximately λ / 2, the reflectance of light with respect to a specific wavelength decreases. The refractive index of the liquid crystal layer 17 is 1.5. Although this varies depending on the liquid crystal material, it is in the range of 1.5 to 1.6 in most cases, and the variation of its refractive index does not significantly affect the design of the dielectric multilayer thin film.

In each table, the number of layers is 24 (ITO
The number of layers is 23 except the thin film 13, but the number is not limited to this. It may be further laminated, or conversely at least good. When the amount is small, the reflectance of the specific visible light decreases. Almost 100% of the specific visible light is reflected if a large number of layers are stacked. This should be determined by the manufacturing cost of the stack and the desired properties.

Further, by combining (stacking) any two of (Table 1) to (Table 3), it becomes possible to reflect light of two wavelengths. For example, (Table 1) and (Table 2)
By laminating the two, the dielectric multilayer film 16 that reflects B light and G light can be formed. Also, from (Table 1) to (Table 3)
If all of the above are laminated, the dielectric multilayer film 16 that reflects all the R, G, and B lights can be formed.

It is also important that the thickness of the ITO thin film 13 is changed according to the wavelength of light modulated by the display panel. However, it is not limited to this. This is because it is possible to use other film thicknesses by optical design. Since the ITO thin film and HfO ₂ both have a refractive index of 2.0,
The physical thickness of the TO thin film is thinned, and Hf is reduced by the thinned amount.
The physical film thickness of the ITO thin film having a specified film thickness may be supplemented with O ₂ .

A design example (Table 1) when the dielectric multilayer film 16 of the display panel reflects B light is shown. The characteristic diagram is shown in FIG. The dielectric multilayer film 16 transmits light in the ultraviolet region and reflects B light. Similarly, a design example in the case of reflecting G light is shown in (Table 2), and its characteristic diagram is shown in FIG. Furthermore, a design example in the case of reflecting R light is shown in (Table 3), and its characteristic diagram is shown in FIG.

Each dielectric multilayer film 16 transmits ultraviolet rays when the UV resin of the mixed solution is cured. When the display panel is used as a light valve, it functions as the BM 381 because it reflects specific visible light.

Although the dielectric multilayer film 16 transmits ultraviolet light and reflects visible light, it should not be limited to this. In the case where the polymer 332 is a visible light curing type, it suffices that specific visible light is transmitted and light of a wavelength modulated by the display panel is reflected. For example, when the display panel modulates R light, the dielectric multilayer film 16 transmits B light and the polymer 33
2 may be hardened, R light may be reflected and it may function as BM. For example, the dielectric multilayer film 16 having the characteristics shown in FIG. 37 may be used. The above also applies to the following embodiments of the present invention.

Dielectric multilayer film 16 when 23 layers are laminated
The film thickness of B is about 1.5 μm when B light is reflected, and slightly over 2.0 μm when R light is reflected. Since the PD liquid crystal does not need to be rubbed, even if unevenness occurs due to the formation of the dielectric multilayer film 16, there is no problem. The ability to form such a thick dielectric multilayer film is a feature unique to PD display panels.

In order to reflect the entire visible light band (white light) by the dielectric multilayer film 16, two types of design dominant wavelength λ must be used. For example, if the first wavelength λ ₁ is 500
nm, and the second wavelength λ ₂ is 600 nm. First, the first
At the wavelength λ ₁ of the first dielectric multilayer film is formed on the ITO thin film (counter electrode) 13 and the physical film thickness is further obtained at the second wavelength λ ₂ thereof. A second dielectric multilayer film is laminated. If formed as described above, the dielectric multilayer film 16 that reflects light in the entire visible light range and transmits light in the ultraviolet light range can be manufactured. The film thickness of the dielectric multilayer film is about 3 μm, which is twice as large as that in the previous embodiment.

The dielectric multilayer film 16 is formed on the TFT 14, the gate and the source signal line. The dielectric multilayer film has the same position and shape as the BM381 of the conventional TN display panel, which is not so different. That is, it is formed corresponding to the pixel electrode and the pixel shape. As an example of the patterning, SiO ₂ , HfO ₂ can be etched with hydrofluoric acid, ZrO ₂ can be etched with sulfuric acid, hydrofluoric acid, etc., and MgF ₂ can be etched with nitric acid, etc. Since the etching conditions and the like change considerably depending on the permanent deposition conditions of the dielectric multilayer film, it is necessary to perform the condition adjustment while conducting the test. The patterning may be performed using a dry etching technique.

The dielectric multilayer film 16 transmits ultraviolet light. This transmission does not mean that most of the light incident on the counter substrate 11 reaches the liquid crystal layer 17. The ultraviolet light is also absorbed by the glass counter substrate 11, and the ITO of the counter electrode 13 is also considerably absorbed. This means that a part of the incident ultraviolet light reaches the liquid crystal layer 17 and there is a light transmission amount that starts the curing of the UV resin.

A thin film of Cr or the like does not transmit light at all if it has a film thickness of 1000 angstroms or more. By comparison, the dielectric multilayer film 16 sufficiently transmits ultraviolet light. The liquid crystal layer 17 is transmitted through the glass counter substrate 11 and the counter electrode 13.
There is a difference in the amount of UV light reaching the liquid crystal layer 17 and the amount of UV light reaching the liquid crystal layer 17 and the glass counter substrate 11, the counter electrode 13, and the dielectric multilayer film 16. However, there is no objection that the UV resin can be cured.

As described above, since the dielectric multilayer film 16 transmits ultraviolet light, UV of the mixed solution of all the liquid crystal layers 17 is used.
Can cure resin. Therefore, the display panel of the present invention is less likely to change with time and has good stability. Further, since it reflects visible light, it also has a BM function.

When the dielectric multilayer film 16 has a certain thickness or more,
The pixel electrode 15 is caused by an unnecessary electric field distribution that causes a voltage drop.
It has the effect of preventing light leakage from the surrounding area. Hereinafter, this effect will be described with reference to FIG.

The relative permittivity ε of the liquid crystal is about 15 to 30. In comparison, the dielectric constant of the dielectric multilayer film 16 is small. For example, the relative permittivity of SiO ₂ is about 4.

As shown in FIG. 2, lines of electric force 22 are generated between the portions to which the voltage is applied. For example, the source signal line 2
1 between the pixel electrode 15 and the source signal line 21 and the counter electrode 13
In between. The liquid crystal molecules 23 are aligned along the lines of electric force 22. When the liquid crystal molecules 23 are aligned vertically with respect to the array substrate 12, the refractive index of the liquid crystal molecules 23 and the refractive index of the polymer 332 are matched as shown in FIG.
When the liquid crystal molecules 23 are aligned along the lines of electric force 22b in FIG. 2A, the peripheral portion of the pixel electrode 15 is in a light transmitting state, and light leakage occurs from the peripheral portion of the pixel electrode 15. This reduces the display contrast of the display panel.

As shown in FIG. 2B, the dielectric multilayer film 1
6 is formed, the source signal line 2 in the liquid crystal layer 17 is formed.
The number of lines of electric force between 1 and the counter electrode 13 is small (the electric field strength is weak). Liquid crystal molecules 2 below the rising voltage of the liquid crystal
Since 3 is not aligned, the liquid crystal layer 17 on the source signal line 21
Is always scattered. Liquid crystal layer 1 on the source signal line 21
It is difficult to apply a voltage to 7 because the voltage drop in the dielectric multilayer film 16 is large. The thickness of the dielectric multilayer film 16 is 1.5 μm or more, and the thickness of the liquid crystal layer 17 is a little over 10 μm. Since the relative dielectric constant of the dielectric multilayer film 16 is considerably smaller than that of the liquid crystal layer 17, the voltage applied to the liquid crystal layer 17 is low.

If the dielectric multi-layer film 16 is formed to be sufficiently thick and wide, the liquid crystal molecules 23 that are vertically aligned with respect to the array substrate 12 will be eliminated or reduced, and light leakage from the peripheral portion of the pixel electrode 15 will occur. It gets harder. From the effect of preventing light leakage, the dielectric multilayer film 16 preferably has a large film thickness. Further, the thicker it is, the better the specific visible light is reflected. The formation position and the number of layers of the dielectric multilayer film 16 should be determined in consideration of the effect of light leakage.

Although the dielectric multilayer film 16 is formed on the counter electrode 13 in the embodiment shown in FIG. 1, it may be formed on the array substrate 12 as shown in FIG. As shown in FIG. 3, the dielectric multilayer film 16 is formed so as to extend between the adjacent pixel electrodes 15. In this case, in order to prevent light leakage between the pixel electrode 15 and the source signal line 21, the dielectric multilayer film 16 may be designed to have an optical property of reflecting incident light. For example, when the display panel modulates R light, the R light is reflected and is not emitted from the array substrate 12.

The dielectric multilayer film 16 does not need to have the property of transmitting ultraviolet light. Because the counter electrode 13
This is because no ultraviolet light shield is formed on the surface. Note that, as described with reference to FIG. 2B, the dielectric multilayer film 16 also has a voltage drop function. For example, as shown in FIG. The effect of reducing the lines of electric force 22 reaching the liquid crystal layer 17 is as shown in FIG.
It is more effective than when it is formed on top. This is because the dielectric multilayer film 16a is directly formed on the source signal line 21 and shields the electric field from the source signal line 21.

In the previous embodiment, the electric field from the source signal line or the like was shielded by the dielectric multilayer film 16. However, the shield effect can be realized even if the dielectric multilayer film 16 is replaced with another material. Other materials are the liquid crystal layer 1
Material smaller than relative permittivity of liquid crystal of 7 (low dielectric material)
Is. For example, inorganic materials such as SiO ₂ and SiNx,
The polymer 332 of the liquid crystal layer 17, a resist, an organic material such as polyvinyl alcohol (PVA), and the like are exemplified. As an example thereof, the dielectric multilayer film 16a may be made of the low dielectric material in FIGS.

In FIG. 4, the relative dielectric constant of the low dielectric material (dielectric multilayer film) 16a is ε2, the relative dielectric constant of the liquid crystal layer 17 is ε1, the thickness of the liquid crystal layer 17 is d1, and the low dielectric material is Assuming that the film thickness of the (dielectric multilayer film) 16a is d2 and the voltage applied between the counter electrode 13 and the source signal line 21 is V, the voltage V applied to the film thickness d1 of the liquid crystal layer 17 is as follows. It is represented by (Equation 1).

(Equation 1) E = (ε2d1V) / (ε1d2 + ε2d1) The voltage E applied to the film thickness d1 of the liquid crystal layer 17 is the rising voltage of the liquid crystal (the liquid crystal is aligned by the voltage, and the transmittance of the liquid crystal layer changes). It is most preferable to set the film thickness of the low dielectric material 16a so as to be less than or equal to the voltage at which the light starts to leak. However, in practical use, there are many cases in which the liquid crystal may be slightly aligned. Generally, when the liquid crystal layer 17 is completely in the transmissive state, the permeation amount is 30%, which is regarded as 100%. That is, the film thickness of the low dielectric material 16a is regulated so that the voltage E applied to the liquid crystal layer 17 has a transmittance of 30% or less.

Matters relating to (Equation 1) are described later, the film thickness of the dielectric multilayer film 16a of FIGS. 6 and 13, and FIGS.
Film thickness of the color filter 71 formed on the signal line shown in FIG. 39, the low dielectric pillar (391a + 391) shown in FIG.
It can also be applied to the height setting of b).

The dielectric multilayer film 16 has a technical effect of preventing light leakage from the periphery of the pixel electrode 15 by functioning as a BM. This effect can also be achieved by shielding the source signal line 21 and the like with a low dielectric material. That is, the technical field of the liquid crystal display panel is the same in that the dielectric multilayer film 16 functions as a BM and that the source signal line 21 and the like are shielded with a low dielectric material.
And the technical problems to be solved are the same.

Of the low dielectric materials, it is preferable to use an organic material, and above all, it is preferable to use a photosensitive resin used for the polymer 332. For example, an ultraviolet curable acrylic resin is exemplified. These resins improve the adhesiveness with the liquid crystal layer 17, and thus have an effect of making it difficult for the liquid crystal layer and the array substrate 12 to be separated from each other.
Further, it can be configured to be relatively thick. This is because the low dielectric film can be easily formed in a short time and at low cost by the resin exposure and development processes. As a matter of course, the thicker the low dielectric film (dielectric multilayer film) 16a, the higher the shielding effect and the effect of preventing the lateral electric field.

The low dielectric film (dielectric multilayer film) 16a
It is not limited to. For example, a low dielectric pillar 391 may be used as shown in FIGS. 38 and 39. FIG. 38 shows an example applied to a transmissive display panel, and FIG. 39 (a) shows an example applied to a reflective display panel.

The low dielectric pillar 391 is preferably formed on the counter substrate 11 side. The counter substrate 11 side is the counter electrode 1
This is because the layers other than 3 are not formed, the surface of the substrate has smoothness, and there is no possibility that the TFT 14 or the like is destroyed by static electricity.

The low dielectric material column 391 is not limited to the columnar shape. For example, as shown in FIG. 39B, a low dielectric pillar 391b is formed on the array substrate 12,
The low dielectric pillar 391a may be formed on the counter substrate 11.

If the low dielectric pillar 391 is formed in a columnar shape, the film thickness of the liquid crystal layer 17 can be kept constant by the low dielectric pillar 391. Therefore, it is not necessary to spray the black beads 19. Therefore, the manufacturing process of the display panel is simplified. Further, since there is no obstacle such as the black beads 19 on the pixel electrode 15, good image display can be realized.

As described above, the low dielectric pillar 391 and the low dielectric film 16a can be easily formed in the PD display panel by the T
This is because an alignment treatment called rubbing is not required unlike the N display panel. If the low-dielectric pillar 391 and the low-dielectric film 16a are formed, the alignment treatment called rubbing is impossible. This is because the rubbing cloth is caught on the low dielectric pillar 391 or the low dielectric film and the surfaces of the counter substrate 11 and the array substrate 12 are not rubbed well.

As shown in FIG. 38 and the like, the source signal line 21
If the lines of electric force generated from the
It is possible to reduce light leakage in the peripheral portion. This is because electromagnetic coupling between the source signal line 21 and the pixel electrode 15 can be prevented.

The low dielectric film and the low dielectric pillar 391 may be colored. By coloring, the light diffusely reflected in the liquid crystal layer 17 can be absorbed and the image quality is improved. As described for the light-shielding film 18, for example, a black pigment or pigment dispersed in resin may be used, or gelatin or casein may be dyed with a black acid dye like a color filter. . As an example of the black dye, it is possible to use a single fluoran dye that turns black, and it is also possible to use a color arrangement black in which a green dye and a red dye are mixed.

Although the above materials are all black materials,
When the display panel of the present invention is used as a light valve of a projection type display device, the present invention is not limited to this, and the low dielectric pillar 391 of the display panel that modulates R light may absorb R light. Therefore, a natural resin can be dyed with a dye, or a material in which a dye is dispersed in a synthetic resin can be used. For example, an azo dye, an anthraquinone dye, a phthalocyanine dye, a triphenylmethane dye or the like may be used alone or in combination of two or more of them.

Further, a structure in which the BM 381 is formed on the low dielectric pillar 391 can be considered. In this case, as shown in FIG. 38, the BM 381 is interposed between the low dielectric pillar 391 and the counter electrode 13.
To form. With this structure, light leakage from the periphery of the pixel electrode 15 is completely eliminated.

The display panel shown in FIGS. 1 and 2 has a pixel electrode 1
Although 5 is assumed to be a light-transmissive display panel formed of ITO, the present invention is not limited to this, and can be applied to, for example, a reflective display panel in which the pixel electrode 15 is formed of metal. The design of the dielectric multilayer film 16 is (Table 1), (Table 2),
Different from the case of (Table 3). This is because there is no ITO thin film (counter electrode) 13. However, the design method may be performed in the same manner as the dielectric multilayer film 16, and there is no difficulty in realizing it.

In order to further prevent light leakage around the pixel electrode, a light shielding film 51 may be formed around the pixel electrode 15 as shown in FIG. 5B. 5A is a plan view of the array substrate 12 when the counter substrate 11 and the like are removed, and FIG. 5B is a sectional view of the display panel. An example of the light shielding film is a metal thin film made of Cr, and an acrylic resin in which carbon or the like is dispersed is illustrated. Further, the same material as the light shielding film 18 may be used. Even if the liquid crystal molecules 23 are aligned by the lines of electric force 22b in FIG. 2 and transmitted through the liquid crystal layer 17, the light is shielded by the light shielding film 51, so that light leakage in the pixel peripheral portion is eliminated.

The light shielding film 51 is preferably formed at a position where the source signal line 21 and the pixel electrode 15 are close to each other, and more preferably, as shown in FIG.
It is preferable to form it also at a position where 2 and the pixel electrode 15 are close to each other. This is because lines of electric force are generated between the gate signal line 52 and the pixel electrode 15. Other configurations and effects are the same as those in FIG.

As shown in FIG. 6, the array substrate 12 is provided with the dielectric multilayer film 16a, and the counter substrate 11 is provided with the dielectric multilayer film 1a.
6b may be formed. At this time, the dielectric multilayer film 16a may be R-light reflective and the dielectric multilayer film 16b may be G-light reflective. Dielectric multilayer film 16a is formed on both substrates 11 and 12,
By forming the unevenness 16b, both substrates 11, 12 are formed.
The adhesion between the liquid crystal layer 17 and the liquid crystal layer 17 is improved, and peeling or the like is reduced. Further, the band of light reflected by the dielectric multilayer film 16 is widened, and the function as the BM can be enhanced. Also,
In FIG. 6, 16a may be replaced with a low dielectric film formed of resin or the like.

To perform color display on one display panel, as shown in FIG. 7, the pixel electrode 15 or the counter electrode 1 is used.
It is sufficient to form the color filter 71 on the surface 3. The color arrangement of the color filter may be a delta arrangement, a square arrangement, or the like, but any arrangement is possible.

When the color filter 71 is formed on the pixel electrode 15 and also on the signal line such as the source signal line 21 as shown in FIG. 8, the shielding effect is exhibited as shown in FIG. Because the color filter 71 is usually made of resin, the relative permittivity ε is smaller than that of the liquid crystal layer 17. Further, the film thickness of the color filter is relatively large. Therefore, if a color filter is formed on the source signal line 21 or the like, the effect of the electric field shield is exhibited. As shown in FIG. 8, the color filter is superposed on the signal line. For example, the green color filter 71a is superimposed on the red color filter 71c on the source signal line 21a. Preferably, blue and black color filters are further stacked. Then, as shown in FIG. 9, the lines of electric force 22a, 2
2b becomes very weak, and liquid crystal molecules are not aligned along the lines of electric force. Therefore, light leakage from the peripheral portion of the pixel electrode 15 is less likely to occur. By selecting the above configuration, good display contrast can be realized.

Since the portions where the color filters overlap each other absorb light, light leakage does not occur from the peripheral portion of the pixel electrode 15 (or rather, the portion where the color filters of at least two colors overlap).

As the color of the color filter, three colors of R, G, B or four colors of R, G, B and black are used. But,
The present invention is not limited to this, and three colors of yellow, cyan and magenta, or four colors of yellow, cyan, magenta and black may be used.

From the viewpoint that rubbing treatment is not necessary for the light modulation layer, it is preferable to use polymer-dispersed liquid crystals, but the invention is not limited to this. For example, guest-host (guest = dye, host = liquid crystal) liquid crystal may be used. Preferably, the guest-host liquid crystal contains a black dye. There are various modes of guest-host liquid crystal, such as phase transition type. Any of these may be used. In general, when the guest-host liquid crystal layer is in the transmissive state, the color of the color filter formed on the reflective electrode or the like can be seen, and when it is in the non-transmissive state, black color is displayed.

Although FIG. 8 shows a transmissive display panel, the technical idea of overlapping the above color filters can be applied to a reflective display panel as shown in FIG. That is, color filters are formed on the reflective electrodes 121a and 121b, and the color filters are overlapped between the reflective electrodes 121. In this case, since there is no source signal line 21, there is no effect of shielding the electric field from the source signal line. However, when the liquid crystal molecules are aligned in the electric field generated between the reflective electrodes 121a and 121b (hereinafter, referred to as a lateral electric field), and the liquid crystal layer 17 is in the transmissive state (transmissive state), a display unrelated to image display is generated between the pixel electrodes. Displayed) can be prevented.

By forming the color filter between the pixel electrodes and the like as described above, it is possible to prevent light leakage and the like around the pixel electrodes and the like. At least two color filters are overlapped between the reflective electrodes 121. Preferably, three or four color filters are stacked. The overlapped portions hardly transmit light or do not transmit light. Therefore, the overlapped portion functions as a light shielding film. That is, the reflective electrode 12
Light can be prevented from entering the insulating layer 123 from between 1a and 121b. When the invading light is incident on the semiconductor layer of the TFT 14, the TFT 14 causes a photoconductor phenomenon. When the color filters are overlapped to form a light-shielding film, the photoconductor phenomenon can be prevented from occurring and good pixel display can be performed. Further, since the color filters are simply stacked, the cost does not increase.

In the above description, the reflective electrode 12
Although it has been stated that the color filters of two or more colors are overlapped with each other or between the pixel electrodes 15 to form the light-shielding film, the invention is not limited to this. For example, a color filter in which dyes of two color filters are mixed in advance may be prepared, and the mixed color filter may be formed between the electrodes. Therefore, stacking the color filters of two or more colors also includes a system or configuration of forming one or more color filters containing dyes of two or more colors.

The matter of preventing light leakage due to the color filter is the same as the means for solving the problem of light leakage due to the dielectric multilayer film 16. Of course, as shown in FIG. 8, the dielectric multi-layer film 16 may be formed on the counter electrode 13, but even if the dielectric multi-layer film 16 is not provided, light leakage and the like will occur due to the structure of "overlapping color filters". It goes without saying that this can be prevented.

In other words, the technical field of the liquid crystal display panel is the same in that the dielectric multilayer film 16 functions as the BM and that the source signal line 21 and the like are shielded by the color filter, and there is a technical problem to be solved. Are the same.

The ITO thin film (counter electrode) 13 is shown in FIG.
It goes without saying that it may be formed on the dielectric multilayer film 16 as indicated by 0.

As is common to the display panel of the present invention, it is effective to form the insulating film 111 on at least one of the pixel electrode 15 and the counter electrode 13 as shown in FIG. Examples of the insulating film include an alignment film such as polyimide used in a TN liquid crystal display panel, an organic substance such as polyvinyl alcohol (PVA), and an inorganic substance such as SiO ₂ . Organic substances such as polyimide are preferable from the viewpoint of adhesion and the like.

The polymer dispersed liquid crystal layer 17 has a relatively low specific resistance. Therefore, the electric charge applied to the pixel electrode 15 may not be completely retained during the time of one field (1/30 or 1/60 seconds). Liquid crystal layer 1 if not held
7 is not completely transparent and the display brightness is reduced. A thin film made of an organic material such as polyimide has a very high specific resistance. Therefore, the charge retention rate can be improved by forming a thin film made of an organic material on the electrode. Insulating film 111
Also has an effect of preventing the electrode from peeling off the liquid crystal layer 17. This is because nearly half of the material forming the liquid crystal layer 17 is an organic substance made of resin.

Further, when the insulating film 111 made of an organic material is formed, there is also an effect that the pore diameter of the polymer network of the liquid crystal layer 17 or the particle diameter of the water droplet liquid crystal becomes substantially uniform. It is considered that even if the organic residue remains on the counter electrode 13, it is covered with the insulating film 111. The effect of PVA is better than that of polyimide. It is considered that this is because PVA has higher wettability than polyimide. However, according to the results of reliability tests (light resistance, heat resistance, etc.) performed by forming various insulating films 111 on the panel, the polyimide used for the alignment film of the TN liquid crystal is good because it hardly changes with time. is there. Therefore, it is preferable to use polyimide as the insulating film 111.

When the insulating film is formed of an organic material, its thickness is preferably in the range of 0.02 μm or more and 0.1 μm or less, and more preferably 0.03 μm or more and 0.08 μm or less. When the color filter 71 is formed, it is formed on the pixel electrode 15 as shown in FIG. As a matter of course, the color filter 71 may be formed on the counter electrode. In addition, the color filter 71 has an insulating film 111.
In that case, the insulating film 111 may be formed only on the electrode on which the color filter 71 is not formed.

The low dielectric pillar 391 or the low dielectric film (dielectric multilayer film) 16a shown in FIGS.
The configuration relating to the color filter shown in FIGS. 8 and 14, the configuration relating to the black beads 19 and the dielectric multilayer film 16 shown in FIG. 1, the configuration relating to the light shielding film 51 shown in FIG. 5, the configuration relating to the insulating film 111 shown in FIG. Used in any combination in the display panel and the display device. This item applies to any of the active matrix type display panel (reflection and transmission type panel), the simple matrix type display panel or the character display panel shown in FIG.

When the display panel is a reflection type, the dielectric multilayer film 16 may be formed between the reflection electrodes 121 as shown in FIG. Similarly to the case shown in FIG. 1, the dielectric multilayer film 16 in this case transmits the ultraviolet light and reflects the modulated light B
It only has to have the function of M. The structure, effects, etc. of the dielectric multilayer film 16 are the same as those in FIG.

The reflective display panel of the present invention will be described below in some detail. Glass substrate (counter substrate) 1
An antireflection film 124 is formed on one surface of No. 1. The antireflection film 124 has a three-layer structure as shown in FIG. 13 or a two-layer structure as shown in FIG. 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 used properly according to the use of the display panel. Usually, V-coat is used when a display panel is used as a light valve of a projection type display device, and multi-coat is used when the display panel is used as a direct-view type panel.

In the case of multi-coating, aluminum oxide (Al ₂ O ₃ ) has an optical film thickness nd = λ / 4, zirconium (ZrO ₂ ) has nd = λ / 2, and magnesium fluoride (M
gF ₂ ) is formed by stacking nd = λ / 4. Usually, a thin film is formed with λ of 520 nm or a value in the vicinity thereof. In the case of V coating, silicon monoxide (SiO) is used as an optical film having a thickness of nd = λ / 4 and magnesium fluoride (MgF).
₂ ) is nd = λ / 4, or yttrium oxide (Y ₂ O
₃ ) and magnesium fluoride (MgF ₂ ) are laminated to form nd = 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. In addition, Y ₂ O ₃ is more stable in terms of the stability of the substance, which is preferable.

A reflective electrode 121 is formed on the TFT 14 via an insulating film 123. Reflective electrode 121 and TF
The connection portion 122 is electrically connected to T14. As a material of the insulating film 123, an organic material typified by polyimide or an inorganic material such as SiO ₂ or SiNx is used. The surface of the reflective electrode 121 is formed of an Al thin film. Although it may be formed by using Cr or the like, the reflectance is Al.
Since it is lower and hard, the peripheral portion of the reflective electrode 121 is easily broken.

In the display panel of the present invention shown in FIG. 12 and the like,
The TFT 14 is formed below the reflective electrode 121. That is, the reflective electrode 121 functions as a light-shielding film (BM) that prevents incident light scattered by the polymer-dispersed liquid crystal layer 17 from entering the semiconductor layer of the TFT 14, and a function as an electrode that applies a voltage to the liquid crystal layer 17. Also has The reflective electrode 121 is made of a metal material and has a sufficient light shielding effect.
Further, since the structure is simple, cost reduction can be realized.

Source signal lines and the like (not shown) are formed on the array substrate 12. The reflective electrode 121 also has a function of shielding the electric force lines emitted from the signal lines from reaching the liquid crystal layer 17. Therefore, image noise due to the lines of electric force from the source signal line does not occur.

The reflection electrode 121 and the TFT 14 are connected to each other by the connecting portion 1.
Electrical connection is made at 22. In order to make the connection, it is necessary to vapor-deposit the metal thin film (reflection electrode) 121 to a thickness equal to or larger than that of the insulating film 123. The thickness of the insulating film 123 is about 1 μm. Therefore, a step of 1 μm is generated in the connecting portion 122.
Further, since the thickness of the reflective electrode 121 is also 1 μm, a valley of 1 μm is formed between the adjacent reflective electrodes. Since the display panel of the present invention uses the polymer-dispersed liquid crystal, it does not require rubbing, so that there is no obstacle even if there is the step, and the liquid crystal display panel can be manufactured with a high manufacturing yield.

A step of 1 μm occurs at the terminal of the connecting portion 122. Further, the shape of the TFT 14 is patterned on the reflective electrode 121, and irregularities of about 1 μm are generated. Since the display panel of the present invention uses the polymer-dispersed liquid crystal, light modulation is performed as a change in the scattering state. Therefore, a change in the liquid crystal film thickness of about 1 μm due to the step and the unevenness of the TFT 14 hardly affects the light modulation. In a display panel such as a TN liquid crystal in which the optical rotation characteristic is applied to the light modulation, the unevenness would be a fatal damage to the light modulation. In addition, the fact that the display film thickness of the present invention is as thick as 8 μm or more also has a positive effect on the film thickness unevenness of the liquid crystal layer 17.

As is apparent from FIG. 12, BM3 is formed on the counter electrode 13 as in the conventional TN display panel shown in FIG.
81 is not formed. The display panel of the present invention basically has no structure formed by patterning on the counter electrode 13. Therefore, in the step of bonding the counter substrate 11 and the array substrate 12, it is not necessary to align the counter substrate 11 and the array substrate 12, and the manufacturing is facilitated.
If the BM381 and the like are formed, the BM381
It is necessary to perform alignment on the order of μm so as to face the pixel electrode 15.

Further, when the BM 381 is formed, when the liquid crystal layer 17 is irradiated with ultraviolet light to phase-separate the resin component and the liquid crystal component of the liquid crystal layer, the BM shields the ultraviolet light and the BM There is a problem that the resin remains uncured. The uncured resin impairs the stability of the display panel,
The change with time becomes large. Such a display panel cannot be practically adopted.

Furthermore, T, which is one of the conventional display panels, is used.
In the N display panel, it is necessary to use a polarizing plate to make the incident light linearly polarized. Therefore, more than half of the light cannot be used, and the light utilization rate is very low. Since the display panel of the present invention uses the polymer-dispersed liquid crystal, it is not necessary to use a polarizing plate, so that the light utilization rate becomes very high.

The counter electrode 125 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 11 side, and the optical thickness of the ITO thin film is λ / The optical film thicknesses of the second, first thin film, and second thin film are λ / 4, respectively. The ITO thin film also functions as a counter electrode.

The refractive index of the first thin film and the second thin film is preferably 1.60 or more and 1.80 or less. Si as an example
O, Al ₂ O ₃ , Y ₂ O ₃ , MgO, CeF ₃ , WO ₃ , Pb
F ₂ is exemplified. In addition, among others, the first thin film is made of SiO 2.
In addition, when the second thin film is made of Y ₂ O ₃ , an extremely excellent antireflection effect of 0.1% or less can be realized over the entire visible light region.

The counter electrode 125 has the first and second electrodes.
The optical film thickness of the dielectric thin film is λ / 4, and the optical film thickness of the ITO thin film is λ / 2. However, the optical film thicknesses of the first and second dielectric thin films are λ / 4, and the ITO thin film is Optical thickness of λ /
It may be 4.

Further, in terms of the theory of the antireflection film, N
Is an odd number of 1 or more, and M is an integer of 1 or more, the optical thicknesses of the first and second dielectric thin films are (N · λ) / 4,
The optical film thickness of the ITO thin film 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).
It may be λ) / 2.

Furthermore, one of the first and second dielectric thin films can be omitted. In that case, although the performance as antireflection is somewhat lowered, it is often practically sufficient. In this case as well, the theory of antireflection as described above can be applied.

By forming the counter electrode 125, the reflected light can be prevented without entering the liquid crystal layer 17, so that the display contrast can be greatly improved.

The dielectric multilayer film 16 is 16a in FIG.
It may be formed between the reflective electrodes as shown in FIG. Moreover,
The dielectric multilayer film may be replaced with the low dielectric film 16a.
Further, as shown in FIG. 14, a color image can be displayed on one display panel by forming a color filter on the reflective electrode 121.

Polymer-dispersed liquid crystal A display panel using a dispersed liquid crystal has a problem that diffuse reflection of light occurs between a liquid crystal layer and a counter array substrate, resulting in low display contrast. To solve this problem, the display panel 281 of the present invention as shown in FIG.
This can be dealt with by attaching a thick transparent substrate 283 or a concave lens 284. The thick transparent substrate 283 or the concave lens 284 is attached by a transparent connecting agent having a refractive index substantially matching that of the counter substrate 11 or the array substrate 12. Liquid crystal layer 17
The light scattered by is reflected by the light emitting surface and is absorbed by the light absorbing film 285 applied to the ineffective surface. Therefore, the light does not return to the liquid crystal layer 17 again to be scattered (secondary scattering).
Therefore, the display contrast is improved. The above description is explained in more detail in Japanese Patent Application No. 4-145297, so please refer to it.

If the light-shielding pattern 164 of FIG. 15 is formed using the dielectric multilayer film described above, the UV resin under the light-shielding pattern can be cured and the original light-shielding function can be provided. FIG. 16 is an example thereof. 16A is a cross-sectional view parallel to the direction (KK ') of the source signal line 21 in the display panel, FIG.
(B) is a cross-sectional view of the display panel in a direction (JJ ') orthogonal to the direction of the source signal line 21, and a light shielding pattern 151 is formed of a dielectric multilayer film outside the display region.

At the time of manufacturing the display panel, the counter substrate 1
1 and the array substrate 12 are mixed solution injected into the counter substrate 1
Ultraviolet light is emitted from the first side, and the ultraviolet light is transmitted through the dielectric multilayer film (light shielding pattern) 151 to cure the UV resin. Further, after the display panel is completed, when the display panel is used, the light modulated by the display panel is reflected when it enters the dielectric multilayer film (light-shielding pattern) 151. Therefore, the light is not emitted to the array substrate 12 side. The structure of the dielectric multilayer film (light-shielding pattern) 151 is (Table 1) to (Table 3), and the effects and the like have been described with reference to FIG.

The above-described embodiment of the display panel of the present invention relates to the active matrix type display panel in which the TFT and the like are arranged in each pixel electrode. Transmits ultraviolet light,
The technical idea of forming the dielectric multilayer film 16 that reflects visible light and functions as a BM on a display panel can be applied to a simple matrix display panel.

FIG. 18 shows an embodiment in which the technical idea of the present invention is applied to a simple matrix type display panel. A stripe-shaped electrode 171 made of ITO is formed on the electrode substrate 174, and one of the electrode substrates 175 is also made of ITO.
Stripe electrodes 176 are formed. The striped electrodes 171 and 176 are arranged so as to be orthogonal to each other.

In the embodiment shown in FIG. 18, the dielectric multilayer film 17 is used.
2 is formed only on the electrode substrate 174 side. FIG. 17
As shown in (a), the dielectric multilayer film 172 is formed in a portion other than the rectangular opening (pixel) 173. Figure 1
FIG. 17B shows a cross-sectional view taken along the line CC ′ of FIG.
A cross-sectional view taken along line DD 'is shown in FIG. In addition,
Regarding the function of the dielectric multilayer film 172, the same ones as shown in (Table 1) to (Table 3) are used. Also, the effects and functions need not be described again since they have been described with reference to FIG.

Also in the simple matrix type display panel, since different signals are applied between the stripe electrodes 171a and 171b, a lateral electric field is generated between both electrodes. When the liquid crystal molecules are aligned in the horizontal electric field, a light transmitting state or the like is established between both electrodes. If the dielectric multi-layered film 172 is formed, the dielectric multi-layered film 17 can be formed even if a light transmission state occurs.
Since 2 functions as a BM, light leakage does not occur. Therefore, a good image can be displayed. The relative dielectric constant ε of the dielectric multilayer film 172 is smaller than the relative dielectric constant of liquid crystal. Therefore, it also has the effect of the electric field shield shown in FIG. That is, the strength of the lateral electric field can be reduced by the dielectric multilayer film 172.

In FIG. 18, the dielectric multilayer film is formed only on the electrode substrate 174 side, but as shown in FIG.
A dielectric multilayer film may be formed on the electrode substrate 175 side as well.
At that time, it may be formed in a matrix as shown in FIG. 17A, but may be formed in a stripe as shown in FIG. FIG. 20 shows the dielectric multilayer film 1 as shown in FIG.
72a is a view in which the electrode substrate 72a is formed in a stripe shape. In addition, forming in a stripe shape means forming the dielectric multilayer film 172 in a stripe shape between the stripe electrodes 171a and 171b.

FIG. 20 shows a structure in which two electrode substrates shown in FIG. 19A are used and the two electrode substrates are orthogonal to each other. Striped electrodes 176 are formed on the electrode substrate 175, and a dielectric multilayer film 172b is formed between the striped electrodes. The dielectric multilayer film 172b is a stripe-shaped electrode 17
It functions as a BM that prevents a lateral electric field between 6a and 176b and prevents light leakage from between the striped electrodes. Meanwhile, the striped electrodes 171 are also formed on the electrode substrate 174.
And a dielectric multi-layer film 1 is formed between the striped electrodes.
72a is formed. The color filter may be formed on either one of the stripe electrodes 171 and 176. Further, it is apparent that the color filter can function as a light-shielding film by forming the color filter between the stripe-shaped electrodes and stacking the color filters as in the case of FIG.

The above is the display panel for displaying a television image or the like. Besides, the technical idea of the present invention can be applied to a display panel or the like (hereinafter referred to as a graphic display panel) that displays fixed graphics, numbers, and the like.

FIG. 21 is a plan view and a sectional view of the graphic display panel. FIG. 21 shows an example in which the number "8" is displayed, but the number is not limited to this. For example,
It may be a character such as "ON" or "OFF" or a graphic such as "○ X". FIG. 21B shows G- in FIG.
It is a sectional view taken along the line G ′. A reflective electrode 217 formed of a metal thin film or the like is formed on the electrode substrate 215, and a color filter 213 is formed thereon. On the other hand, a transparent electrode 216 made of ITO is formed on the electrode substrate 214,
A dielectric multilayer film 212 is formed thereon. A polymer dispersed liquid crystal layer 17 is sandwiched between both electrode substrates. However, in the electrode substrate 215, 217 may be a color filter and 213 may be ITO.

The color filter 213 is formed on the reflective electrode 217 at least in a wider area than the opening 211. Further, the color reflected by the color filter 213 is preferably matched with the light color reflected by the dielectric multilayer film 212. That is, the liquid crystal layer 17 is in a transparent state (electrodes 216 and 21).
When a voltage is applied between 7), the character "8" disappears. On the contrary, the liquid crystal layer 17 is in a scattering state (electrode 216
When a voltage is not applied between 217 and 217), the liquid crystal layer 17 becomes cloudy, so that the character "8" appears to appear white.

The constitution of the dielectric multilayer film 212 is exemplified by those shown in (Table 1) to (Table 3).
The function and the like are the same as those described with reference to FIG. Further, the dielectric multilayer film 212 may be formed on the surface of the electrode substrate 214 in contact with air as shown in FIG.

FIG. 23 shows a liquid crystal display panel 21 shown in FIG.
It is a block diagram of the display apparatus using 8. Liquid crystal display panel 2
A switch 236 is arranged on the switch 18. The switch 236 is composed of transparent conductive sheets 231a and 231b, and when the transparent conductive sheets 231a and 231b come into contact with each other, electrical conduction is established between the two sheets. The detection means 237 detects whether or not the electrical connection is established. The detection means 2
37 is an inverter 235 and a T-type flip-flop (T-
FF) 234, the logic level of the C output is inverted every time conduction is established between both sheets. That is, the logic level of the C output is inverted every time the user holds the transparent conductive sheet 231a. The analog switch 232 turns on and off the switch S by C output.
Let When the C output is at the H level, the switch S is in the ON state, and when it is at the L level, it is in the OFF state. Switch S is O
In the N state, the rectangular signal from the analog switch 232 is applied to the transparent electrode 216 of the liquid crystal display panel 218, and the liquid crystal layer 17 becomes transparent. When the liquid crystal layer 17 is in a transparent state, the characters on the liquid crystal display panel 218 cannot be seen. On the contrary, when the liquid crystal layer 17 is in a cloudy state, characters can be seen.

From the above, the user can use the transparent conductive sheet 2
By pressing 31a, characters on the liquid crystal display panel 218 can be switched to be invisible or visible. As an application development, O of the power supply of home electric appliances
It can be used for N, OFF display, touch panel of electronic notebook, and the like.

In addition, the technical idea of the present invention can be applied to a photo-writing type liquid crystal display panel using polymer dispersed liquid crystal (for example, Japanese Patent Laid-Open No. 2-93519). Further, it is not limited to the liquid crystal display panel using the polymer dispersed liquid crystal. For example, the effect of reflecting visible light of a specific wavelength to function as a BM is TN display panel, S
It can also be applied to TN display panels. For example, in FIG.
In the above, the BM 381 may be used as the dielectric multilayer film 16.

As is clear from the above description, in the display panel of the present invention, the dielectric multilayer film 16 is formed on the first substrate or the second substrate. The dielectric multilayer film 16 is configured to reflect visible light of a specific wavelength and transmit ultraviolet light, so that the mixed solution is sandwiched between the first substrate and the second substrate and then the ultraviolet light is irradiated. U under the dielectric multilayer film 16
V resin can also be cured. Therefore, since the UV resin in all the sandwiched mixed solutions can be cured, it is possible to obtain a stable display panel which does not change with time.

Further, since the dielectric multilayer film 16 reflects the light incident on the display panel, it also has a light shielding function like the black matrix of the conventional TN display panel.

Further, since the dielectric multilayer film 16 has a lower relative permittivity than liquid crystal, it is possible to reduce the number of lines of electric force generated between the signal line and the counter electrode, and to prevent light leakage in the peripheral portion of the pixel. Etc. can be suppressed. If the light shielding film 51 is formed in the peripheral portion of the pixel electrode, the effect is further enhanced. Further, by forming a color filter or the like so as to overlap between pixels, the color filter can function as a light-shielding film.

As shown in FIG. 38, if the lines of electric force generated from the source signal line 21 are shielded by the low dielectric pillar 391, the light leakage around the pixel electrode 15 can be reduced. This is because electromagnetic coupling between the source signal line 21 and the pixel electrode 15 can be prevented.

Further, it is effective to form the insulating film 111 on at least one of the pixel electrode 15 and the counter electrode 13. By forming the insulating film 111 made of an organic material on the electrode, the charge retention rate can be improved. The insulating film 111 also has an effect of preventing the liquid crystal layer 17 and the electrode from being separated from each other. This is because nearly half of the material forming the liquid crystal layer 17 is an organic substance made of resin.

Further, when the insulating film 111 made of an organic material is formed, there is also an effect that the pore diameter of the polymer network of the liquid crystal layer 17 or the particle diameter of the water droplet liquid crystal becomes substantially uniform. Further, by using the polymer-dispersed liquid crystal, a polarizing plate becomes unnecessary, and a high-brightness display which is at least twice as bright as a TN display panel can be realized. This can not only improve the efficiency of light utilization, but can also significantly reduce the conversion of light into heat, and will not cause deterioration of the performance of the panel due to heating. This is because when the intensity of light incident on a single display panel is as high as tens of thousands of lux, as in a projection display device,
It is very effective.

The projection type display device of the present invention will be described below with reference to the drawings. First, specifications common to the projection type display device of the present invention will be described. The following values or range of values are important matters especially for a projection display device using a display panel having a polymer-dispersed liquid crystal as a light modulation layer as a light valve.

In the projection type display apparatus of the present invention, from the viewpoint of improving the light utilization rate, it is necessary to increase the F number of the illumination light as the panel effective display size (display area of the panel) decreases. If the panel effective display size d is increased, the F number of the illumination light can be decreased, and as a result, a bright large screen display can be realized. However, if the panel effective display size becomes large, the system size of the projection type display device becomes large, which is not preferable. Further, if the effective display size of the panel is reduced, the luminous flux per unit area incident on the display area of the panel is increased, which is not preferable because the panel is heated.

If the luminance of the luminous body is set to 1.2 × 10 ⁸ nt in consideration of the lamp life, the arc length and the power consumption of the lamp are considered to be approximately proportional. As an example, a lamp having an arc length of 3 mm has a power of 50 W, a lamp having an arc length of 4 mm has a power of 100 W, and a lamp having an arc length of 5 mm has a power of about 150 W. Metal halide lamp efficiency is 80 lm / W
Is. The total luminous flux of a 50 W lamp is 4000 lm, 10
The total luminous flux of a 0 W lamp is 8000 lm, and the total luminous flux of a 150 W lamp is 12000 lm. The lamp arc length and the lamp power consumption are correlated, and the arc length and the F number are correlated.

In the projection type display device, the screen size of the projected image is 40 inches or more, and the luminous flux of 300 to 400 lm or more is required to obtain the viewing angle and the image brightness in the practical range. Therefore, if the light utilization rate of the lamp is about 4%, a lamp of 100 W or more must be used. From this, a lamp having an arc length of 3 mm can be used only for obtaining a good display contrast (CR), but a metal halide lamp of 100 W or more is required to obtain a sufficient brightness of a projected image. .

If the panel effective display size is also small, sufficient display brightness cannot be obtained. If the arc length is 5 mm and the effective F value of the illumination light is 7, the panel effective display size needs to be about 3.5 inches. If the arc length is about 5 mm and the panel effective display size is more than 2 inches, the effective F value of the illumination light is less than 5. In this case, the display brightness is in the practical range, but good display contrast (C
R) cannot be expected.

As a result of various experiments and examinations, effective F of illumination light
When the value is 5 or more, display brightness in a practical range can be obtained. However, in order to obtain good display brightness, display contrast, proper power consumption and lamp life, the effective F value of the illumination light (= effective F value of the projected light) is around 7, the arc length of the lamp is around 5 mm, As a result, it was necessary to use W of about 150 W.

When the F number of the projection lens is lowered, the screen light flux reaching the screen becomes higher. Along with that, the power consumption of the lamp must be increased. Further, when the power consumption of the lamp is increased from the viewpoint of extending the life of the lamp, the arc luminance becomes long when the arc brightness is considered to be constant. Naturally, the display contrast (CR) becomes worse as the F number becomes smaller. vice versa,
When the F number of the projection optical system is increased, the display contrast is increased, but the screen light flux is decreased.

As a result of various experiments and examinations, regarding the lamp, the arc length is 3 m in order to obtain a good display contrast.
It must be between m and 6 mm. Further, it should be 250 W or less in terms of power consumption. In addition, a metal halide lamp of 100 W or more must be used to obtain the screen brightness. More preferably, considering the screen brightness and display contrast, the arc length should be 3 mm or more and 6 mm or less.

The diagonal length of the effective display area of the panel must be 4.5 inches or less in terms of system size.
Further, it must be 2 inches or more in terms of light utilization efficiency. Above all, in order to obtain sufficient light condensing efficiency and to be compact, it is preferably 3 inches or more and 4 inches or less.

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 good contrast (CR). Further, it must be 9 or less in order to obtain sufficient screen brightness. Further, considering the above-mentioned arc length of the lamp, the F number must be 6 or more and 8 or less.

If the divergence angle (F number) of the illumination light does not substantially match the converging angle (F number) of the projection lens, the light utilization rate will decrease. This is because the F number is restricted to the larger one. The F-number of the illumination light of the projection type display device of the present invention and the F-number of the projection lens are matched.

In the above description, for example, the arc length of the lamp of 5 mm means "substantially 5 mm". Substantially 5 mm means an arc length of 8 m
Even if the length is m, if the projection lens can collect only the light emitted from about 5 mm in the center of the arc among the light emitted from the arc, the arc length is substantially 5 mm. Similarly, the F number means a valid 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.

FIG. 24 is a block diagram of the projection type display device of the present invention in the first embodiment. However, components that are unnecessary for the description are omitted. The light source 241 has a concave mirror 24 inside.
1b and a metal halide lamp or a xenon lamp as the light generating means 241a are arranged. Also,
A UVIR cut filter 241c that cuts ultraviolet rays (UV) and infrared rays (IR) is arranged on the light emission side. The concave mirror 241b is designed to have an appropriate value according to the arc length of the lamp 241a. As the concave mirror 241b, an ellipsoidal mirror or a parabolic mirror is used. Further, 242a is a dichroic mirror (BDM) that reflects B light, 242b is a dichroic mirror (GDM) that reflects G light, 2
42c is a dichroic mirror (RD) that reflects R light.
M). In addition, from BDM242a to RDM242c
The arrangement of is not limited to the order shown in FIG. It goes without saying that the last RDM 242c may be replaced with a total reflection mirror.

Reference numeral 243 is a display panel of the present invention. For example, FIG. 1, FIG. 3, FIG. 5, FIG. 11, FIG. 16, FIG.
The display panel of 8 corresponds. However, the liquid crystal layer 17 of the display panel 243c that modulates the R light is made thicker than the film thickness of the liquid crystal layer 17 of another display panel that modulates the G and B lights. Further, the average particle diameter of the water droplet liquid crystal or the average pore diameter of the polymer network is changed according to the wavelength of light to be modulated. The longer the wavelength of the modulated light, the larger the average particle diameter or average pore diameter. This is because the longer the wavelength of light, the lower the scattering characteristics and the lower the contrast. Further, the dielectric multilayer film 16 is formed on the display panel,
The dielectric multi-layer film 16 reflects incident light and functions as a BM. 244 is a lens, 246 is a projection lens, and 245 is an aperture as a diaphragm. The projection optical system is composed of 244, 245, and 246. It should be noted that the aperture 245 is for illustration of the operation of the projection type display device. Since the aperture 245 defines the converging angle of the projection optical system, it may be considered to be included in the function of the projection optical system. That is, if the F value of the projection optical system is large, it can be considered that the hole diameter of the aperture 245 is small. In order to obtain a high-contrast display, the larger the F value of the projection optical system, the better. However, the larger the brightness, the lower the brightness of white display. Specifically, the aperture is not used, and the function of the projection optical system includes the function of the aperture. 247 is a relay lens.

FIG. 40 is a perspective view showing FIG. 24 more specifically. However, relay lens 2
Parts such as 47 that are unnecessary for the description are omitted. Further, FIG. 41 shows a configuration of a cabinet 425 of a projection type display device using the projector 421 shown in FIG. A transmissive screen 424 is arranged on the upper front side of the cabinet 425, a projector 421 is arranged on the lower rear side, a plane mirror 422 is arranged on the lower front side, and a plane mirror 423 is arranged on the rear side of the screen 424. The projection distance (optical path length from the projection lens to the center of the screen) is shortened, and the projector 42
By making 1 small, the cabinet 425 can be made compact.

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

White light is emitted from the light source 241 and the B light component of this white light is reflected by the BDM 242a. This B light is incident on the display panel 243a. Display panel 2
Reference numeral 43a modulates the light by controlling the scattering and transmission states of the incident light by the signal applied to the pixel electrode as shown in FIGS. 34 (a) and 34 (b).

The scattered light is shielded by the aperture 245a, and conversely, the parallel light or the light within a predetermined angle is opened by the aperture 24.
Pass 5a. The modulated light is enlarged and projected on a screen (not shown) by the projection lens 246a. As described above, the B light component of the image is displayed on the screen. Similarly, the display panel 243b modulates the G light component light, and the display panel 243c modulates the R light component light, so that a color image is displayed on the screen.

Although FIG. 24 shows a method of enlarging and projecting on the screen by three projection lenses 246, there is also a method of enlarging and projecting with one projection lens. The block diagram is shown in FIG. The display panel of the present invention is used as the display panel 254.

Here, in order to facilitate the explanation, 254G
Is a display panel for displaying an image of G light, 254R is a display panel for displaying an image of R light, and 254B is a display panel for displaying an image of B light. Therefore, regarding the wavelengths that are transmitted and reflected by each dichroic mirror, the dichroic mirror 252a reflects R light and transmits G light and B light. The dichroic mirror 252c reflects G light and
Allows light to pass through. The dichroic mirror 252b transmits B light and reflects G light, and the dichroic mirror 252d reflects B light and transmits G light and R light.

The light emitted from the metal halide lamp 241a is reflected by the total reflection mirror 251a, and the direction of the light is changed. Then, the UVIR cut filter 241c cuts the light having wavelengths in the ultraviolet region and the infrared region. The light from which the ultraviolet rays and the infrared rays have been cut is separated by the dichroic mirrors 252a and 252b into the optical paths of the three primary colors of R, G, and B lights.
The G light and the B light are incident on the field lens 253B. Each field lens 253 collects each light, and the display panel 2
54 changes the orientation of the liquid crystal corresponding to the video signal, and modulates the light. The R, G, and B lights thus modulated are combined by the dichroic mirrors 252c and 252d, and the projection lens 255 screens (not shown).
Will be enlarged and projected.

Needless to say, the simple matrix type display panel described in FIGS. 18 and 20 in the projection type display device shown in FIGS. 24 and 25 can also be used as the light valve. In addition, the configuration shown in FIG.
The rear projection type display device shown in FIG.

The structure of the projection type display device of the present invention using the reflection type display panel shown in FIG. 12 as a light valve will be described below. FIG. 26 is a configuration diagram of an embodiment of a projection type display device using the reflection type display panel 264 of the present invention shown in FIG. 12 and the like as a light valve. The light source 241 includes a lamp 241a, a concave mirror 241b, and a UVIR cut filter 241c. The lamp 241a is a metal halide lamp and emits light including color components of three primary colors of R, G, and B. The concave mirror 241b is made of glass, and has a reflective surface on which a multilayer film that reflects visible light and transmits infrared light is deposited. UVIR cut filter 241
Reference numeral c is a glass substrate on which a multilayer film which transmits visible light and reflects infrared light and ultraviolet light is vapor-deposited. Lamp 241a
Visible light included in the emitted light from is reflected by the reflecting surface of the concave mirror 241b. The reflected light emitted from the concave mirror 241b is emitted after the infrared rays and ultraviolet rays are removed by the UVIR cut filter 241c.

The projection lens 261 includes a first lens group 261b on the display panel side and a second lens group 261a on the screen side.
And a first lens group 261a and a second lens group 2
A plane mirror 262 is arranged between the plane mirror 61b and 61b.
The scattered light emitted from the pixel in the center of the screen of the display panel 264, after passing through the first lens group 261b, is approximately half incident on the plane mirror 262 and the rest is not incident on the plane mirror 262, and the second lens group is not incident. It is incident on 261a. The normal line of the reflecting surface of the plane mirror 262 is the optical axis 26 of the projection lens 261.
It is tilted at 45 ° with respect to 5. The light from the light source 241 is reflected by the plane mirror 262, passes through the first lens group 261b, and enters the display panel 264. Display panel 264
The reflected light from is transmitted through the first lens group 261b and the second lens group 261a in this order and reaches the screen. A light ray that exits from the center of the aperture of the projection lens 261 and heads for the display panel 264 is incident on the liquid crystal layer 17 almost vertically.
In other words, it is telecentric.

Here, in order to facilitate the explanation, 264
It is assumed that a is a display panel that modulates R light, 264c is a display panel that modulates B light, and 264b is a display panel that modulates G light.

In FIG. 26, reference numeral 263 is a dichroic mirror, which serves both as a color combining system and a color separating system. The white light emitted from the light source is reflected by the plane mirror 262, and the first group 261b of the projection lens 261.
Incident on. At this time, the UVIR cut filter 241c
Thus, unnecessary B light and R light are cut. UVIR
The band of the cut filter 241c is a half value of 430 nm.
Is about 690 nm. Hereinafter, when describing the band of light, it is expressed by half value. The dichroic mirror 263a reflects G light and transmits R light and B light. The G light is band-limited by the dichroic mirror 263c, and the display panel 264
incident on b. The band of G light is 510 to 570 nm. On the other hand, the dichroic mirror 263b reflects B light and transmits R light. B light is displayed on the display panel 264c,
The R light is incident on the display panel 264a. The band of incident B light is 430 nm to 490 nm, and the band of R light is 600 n.
m-690 nm. The bands of these lights are the same for other projection type display devices of the present invention. Each display panel forms an optical image as a change in the scattering state according to each video signal. The optical system formed by each display panel is color-synthesized by the dichroic mirror 263, and the projection lens 2
It is incident on 61 and is enlarged and projected on the screen 266.

As shown in FIG. 26, the color separation optical system is constructed by using a dichroic mirror, and the dichroic mirror has a color separation function and a color combination function for combining the lights modulated by the liquid crystal display panel.

By using a reflective structure for the display panel,
As shown in FIG. 27, the heat dissipation plate 271 and the like can be directly arranged on the back surface of the array substrate or the counter substrate. The heat dissipation plate 271 is attached to the display panel 264 with a silicone adhesive. With this structure, the display panel can be easily cooled.

Light incident on the display panel is transmitted from the counter electrode 125 to the reflective electrode 121 (incident path) and the reflective electrode 1.
From 21 to the counter electrode 125 (outgoing path), the light passes through the liquid crystal layer 17 twice. Therefore, the liquid crystal film thickness is apparently equivalent to that of the transmissive display panel. Therefore, compared with the transmissive display panel, the scattering performance is improved, and high contrast display can be realized.

The dichroic mirror 263 functions as a filter that reflects (transmits) light of a specific wavelength.
For example, the dichroic mirror 263a uses the light source 241.
When the light from is incident on the display panel 264b, it reflects light of a specific wavelength. Further, when the light reflected by the display panel 264b enters the projection lens 261, it reflects light of a specific wavelength.

One dichroic mirror 263 reflects light twice when entering the display panel and when entering the display panel. In the configuration of FIG. 13, one dichroic mirror limits the wavelength band of light twice. That is, the dichroic mirror functions as a secondary filter.
Compared with the dichroic mirror 242 of FIG. 24, the cutoff characteristic for band limitation becomes steeper. Therefore, overlap does not occur in the band of light incident on each display panel. Therefore, color reproducibility is improved, and high-quality image display can be realized.

Further, the dichroic mirror 263 has both the color separating function and the color synthesizing function, so that the system size of the projection display apparatus can be reduced.

Further, in order to make the color separation and color combining optical system compact by using the dichroic mirror, it may be constructed as shown in FIG. 42 in FIG.
Reference numeral 26 is an auxiliary lens. The three dichroic mirrors 263d, 263e, and 263f are arranged in combination in an X shape. The incident light 267a is separated into three primary color lights of R, G and B by the three dichroic mirrors 263d, 263e and 263f. For example,
The dichroic mirror 263d reflects R light, and the dichroic mirrors 263e and 263f reflect B light. The G light passes through the three dichroic mirrors and reaches the display panel 264e. Each separated light is modulated by the display panels 264d, 264e and 264f of the present invention. The modulated light becomes emitted light 267b,
The colors are combined by the dichroic mirror 263 and projected by the projection lens 261.

Incidentally, FIGS. 24, 25, 26 and 4
In 2 above, the dichroic mirror separates the light into the three primary colors of R light, G light, and B light, but the invention is not limited to this. For example, dichroic filters,
A dichroic prism or the like may be used.

FIG. 44 is a block diagram of a projection type display device for performing color separation and color synthesis using the dichroic prism 441. The dichroic prism 441 has two light separating surfaces 442a and 442b.
At 2, the incident light 267a is separated into three primary color lights of R, G and B. Each display panel 264 has a light wavelength limiting filter 433.
It is attached to the dichroic prism 441 via. That is, the optical wavelength limiting filter 433 is optically coupled to the dichroic prism 441 by the optical coupling agent 282, and the optical wavelength limiting filter 43 is also used.
3, a display panel 264 is attached by being optically coupled with an optical coupling agent 282.

Examples of the optical coupling agent 282 include an adhesive such as an acrylic resin, a gel containing silicon resin as a component, and a liquid such as ethylene glycol. Many of these optical coupling agents have a refractive index close to that of the substrate of the display panel, and are practically sufficient.

The dichroic prism 441 is exemplified by one formed entirely of glass or resin.
In addition, a frame (container) is made of glass or the like, and a plate having a light separation surface 442 is inserted into the frame, and the space of the frame is approximately equal to the refractive index of the material of the frame such as ethylene glycol. It may be filled with a liquid or the like. Other than ethylene glycol, a gel such as a silicone resin may be used.
The difference in refractive index between the frame and the liquid or gel is 0.1.
5 or less, and the range of refractive index is 1.40 or more and 1.5
It is desirable to set it to 5 or less.

As shown in FIG. 45, a light absorbing film (black paint or the like) 432 is applied to the invalid area of the dichroic prism 441 (area other than the surface on which the light input / output surface 435 and the display panel 264 are attached). There is. As the material, the same material as the light absorption film 285 shown in FIG. 29 and the like is used. The light absorption film 432 has a function of absorbing light scattered by the display panel 264. That is, the display panel 2
It need only have a function of absorbing the light scattered by 64, and is not limited to black. For example, a paint having a complementary color to the light color modulated by the light modulation liquid crystal layer 17 may be used.

Furthermore, the term light absorbing film should be understood to include other light absorbing means. For example, a structure in which a thin film is formed in the invalid region of the dichroic prism 441 by a vapor deposition technique to form the light absorbing film 432, a plate or a film that absorbs light is attached to the invalid region of the dichroic prism 441, and the invalid region of the dichroic prism 441 is formed. An example is a configuration in which it is polished to a scattering state.

Examples of the light wavelength limiting filter 433 include a dichroic mirror and a dichroic filter, and a filter in which a dye absorbing light is contained in glass or resin is illustrated. Any of these may be used in the projection type display device of the present invention, but it is most preferable to use a dichroic filter capable of narrowing the optical band.

In FIG. 44, the optical wavelength limiting filter 433
Is disposed between the display panel 264 and the light separating surface 442 for the following reason.

On the light separating surface 442 of the dichroic mirror or dichroic prism, a transparent dielectric film having a different refractive index is laminated on the transparent plate or prism surface with a film thickness of about the wavelength of light. The laminated transparent dielectric thin film has a function of splitting into a transmission wavelength range and a reflection wavelength range at an arbitrary wavelength by a multiple interference phenomenon of light, with almost no light absorption loss. It is known that such an optical multilayer film has a remarkable difference in spectral characteristics corresponding to P-polarized light and S-polarized light as the incident angle of incident light entering the light separation surface increases from zero.

Here, P-polarized light and S-polarized light will be defined. P-polarized light refers to light that oscillates on a light separation surface 442 such as a dichroic prism and a surface including the traveling direction of an incident light ray. The S-polarized light refers to light that vibrates in a direction perpendicular to the vibrating direction of the P-polarized light.

In the case of a projection type display device using a TN type display panel, since a polarizing plate is used, its polarization axis is arranged so as to use only P polarized light or S polarized light, and only one polarized light is used. Is used. Therefore, even if polarization dependence of the spectral characteristics of the dichroic mirror or the dichroic prism occurs, sharp color separation characteristics can be obtained, and a good hue of the projected image can be obtained.

On the other hand, when a PD display panel or the like is used, random light (both P-polarized light and S-polarized light) becomes incident light. Therefore, the dichroic mirror and the dichroic prism exhibit a spectral action corresponding to the average value of P-polarized light and S-polarized light in their spectral characteristics. In other words, sharp wavelength cut is not possible. This means that the color purity of light entering one display panel is lowered.
Therefore, the hue of the color-synthesized projection image is inferior to that of the projection display device using the TN display panel.

Light separation surface 4 such as a dichroic prism
It is known that the light reflected by 42 has a wider band for S-polarized light than for P-polarized light. On the contrary, the light transmitted through the light separation surface 442 of the dichroic prism is wider in the P polarized light than in the S polarized light.

For example, the dichroic prism 44
If the first light splitting surface 442a reflects R light, the S-polarized component of the R light reflects light of a wide wavelength band,
The P-polarized light component of the R light transmits light of a wide wavelength band. Therefore, the S-polarized R light also reflects light close to the G light band, and the P-polarized R light also transmits light close to the G light band.

That is, it means that the R light cannot be separated well at the light separation surface 442a of the dichroic prism 441. This is a factor that deteriorates the hue. The deterioration of the hue can be replaced with the deterioration of the color reproducibility.
For example, a display panel 264d that originally modulates only R light
In addition, since G light is mixed with light incident on the panel, G light is also modulated as R light, and the color of the original image cannot be reproduced.

As shown in FIG. 43, in the projection display apparatus of the present invention, the light wavelength limiting filter 433a limits the band of transmitted light to the narrow band of P-polarized light and S-polarized light. That is, in the light incident on the display panel 264d, the band of S-polarized light is wider than that of P-polarized light,
The band of the transmitted light of the optical wavelength limiting filter 433a is limited to the P-polarized band. Especially when a dichroic prism is used, the deviation between the P-polarized light band and the S-polarized light band tends to increase, and therefore the effect of using the optical wavelength limiting filter 433 is great.

Similarly, in the light incident on the display panel 264f, the band of S-polarized light is wider than that of P-polarized light, so that the band of transmitted light of the optical wavelength limiting filter 433c is P.
Limit to the band of polarization. Further, in the light incident on the display panel 264e, the band of P-polarized light is wider than that of S-polarized light, so the band of transmitted light of the optical wavelength limiting filter 433b is limited to the band of S-polarized light.

From the above, it is effective to arrange the light wavelength limiting filter 433 between the display panel 264 and the dichroic mirror 263 in the configuration of FIG. 42 as well.
Therefore, the technical idea of disposing the light wavelength limiting filter 433 between the light separating surface 442 and the display panel 264 is not limited to the use in combination with the dichroic prism 441 of FIG. For example, in FIG.
It can also be applied to the configurations of FIG. 4, FIG. 25, and FIG.

Further, the optical wavelength limiting filters 433a and 43
Not all 3b and 433c have to be placed in each optical path. For example, the optical wavelength limiting filters 433a and 433c may be used and 433b may be removed. This is because the purpose of improving the color reproducibility can be achieved by inserting the optical wavelength limiting filter only in the optical path having poor color purity.

In FIG. 26, the optical wavelength limiting filter 433 is shown by a dotted line. However, the display panel 264 may have a configuration in which an optical wavelength limiting filter is optically coupled with an optical coupling agent. Further, in order to prevent the light reflected by the light wavelength limiting filter from entering the projection lens 261, it is preferable to form an antireflection film on the surface of the light wavelength limiting filter in contact with air. In addition, it is preferable to dispose the optical wavelength limiting filter with respect to the optical axis 265.

The display panel 264 is attached to the dichroic prism 441, and the light absorbing film 432 is applied to the ineffective region of the dichroic prism 441.
As shown in FIG. 29 and the like, this configuration has a display panel 264.
It is functionally similar to that the transparent substrate 283 is optically coupled to the transparent substrate 283 and the light absorbing film 285 is applied to the ineffective region of the transparent substrate 283. That is, the transparent substrate 2
It may be considered by replacing 83 with the dichroic prism 441.

For example, considering the display panel 264a as the center, and considering that the display panel 264a modulates the R light, the incident light 267a becomes the dichroic prism 441.
Is incident on the light input / output surface 435 of
Light is reflected. The display panel 264a has the reflective electrode 121.
The degree of scattering of the light modulation liquid crystal layer 17 is changed according to the magnitude of the voltage applied to the. A component of the transmitted light is reflected again by the light separation surface 442 a and is emitted from the light incident / emission surface 435. Most of the scattered light is incident on the light absorption film 432 and is absorbed, and returns to the light modulation liquid crystal layer 17 again so that secondary scattering is not generated.

From the above, it can be understood that the dichroic prism 441 in FIG. 44 has a function of color separation and color combination and a function of preventing generation of secondary scattered light. In the configuration of the present invention shown in FIG. 44, the color separation / color synthesis system is very simple and compact. It also has the function of preventing secondary scattering.

Also, the configuration of FIG. 43 may be considered. A dichroic mirror (a half mirror in which a dielectric multilayer film is formed on a glass plate or the like and which selects a wavelength of light and reflects the light by an optical interference phenomenon) 263, a light wavelength limiting filter 433, and a display in a cubic container 431. A panel 264 is arranged. A light absorbing film 432a as a light absorbing means is formed on the inner surface or the outer surface of the container 431. The space of the container 431 is filled with a liquid such as ethylene glycol or a gel 434.

With the above structure, it is not necessary to establish optical coupling between the light wavelength limiting filter 433 and the display panel 264. The light absorption film 432a is shown in FIG.
5 functions as the light absorption film 432. Further, since the ethylene glycol liquid 434 has a function of liquid-cooling the display panel 264, it is easy to cool the display panel 264.

When the light wavelength limiting filter 433 is used in a reflection type projection type display device (eg, FIG. 26, FIG. 44, etc.), the light wavelength limiting filter 433 receives light when it enters the display panel 264. There is a pattern in which the light passes through the display panel 264 twice. Therefore,
The optical wavelength limiting filter 433 apparently functions as a secondary bandpass filter. Therefore, it has a feature that the cutoff band is steep and the wavelength selectivity is excellent.

Note that the display panel 264 is preferably the display panel of the present invention, but may be replaced with another display panel for modulating random light. For example, an optical writing type display panel disclosed in U.S. Pat. No. 5,148,298, a display panel for performing light modulation by a minute mirror tilt disclosed in USP 4566935, or a diffraction phenomenon disclosed in Japanese Patent Laid-Open No. 62-237424. A display panel that performs light modulation is exemplified.

From the above, the projection type display device shown in FIG. 43, FIG. 44, etc. has two technical inventions and effects. One is to optically couple a display panel to a prism and prevent secondary scattered light by the prism.
The second is to improve the hue by the optical wavelength limiting filter.

The above device is a projection type display device using a display panel for forming an optical image as a change in the light scattering state as a light valve (light modulating means). However, the technical idea of converting P-polarized light and S-polarized light by the phase plate of the present invention, narrowing the bandwidth of light in the color separation / color combining system, and improving the hue of the projection display device is based on another random. It is also applied to a projection type display device using a display panel that modulates light.

The projection type display device includes a rear type projection type display device (see FIG. 41, usually called a projection television) in which the screen and the projection device are housed in one cabinet, and a front side where the screen and the projection device are separated. There is a projection type display device (manufactured by Sharp Corporation). The projection type display device of the present invention can be applied to both the rear type and the front type. For example, if the projection type display device shown in FIG. 24, FIG. 26 or FIG. 44 and the screen are integrated and configured as shown in FIG. 41, the rear projection type display device is obtained.

Further, in order to realize color display using one display panel of the present invention, the structure as shown in FIG. 28 may be used. In addition, in order to realize color display using a single reflection type panel, an optical system for modulating light of one color of RGB in FIG. 28 is taken out, and a reflection valve of the present invention shown in FIG. 14 is used as a light valve. It goes without saying that a display panel may be used.

The display panel of the present invention can be used not only as a light valve of a projection type display device but also as a display device (called a viewfinder) used for a video camera, for example. An embodiment in which the display panel of the present invention is used in a viewfinder will be described below. When the display panel of the present invention is used in the viewfinder, the dielectric multilayer film 16 is formed so as to reflect white light. Besides, as the display panel, the display panel of the present invention shown in FIG. 7, FIG. 8, FIG. 10, FIG.

FIG. 30 is an external view of the viewfinder of the present invention, and FIGS. 31 and 32 are sectional views of FIG. Inside the body 291, a condenser lens 304 and an attachment holder 307 to which the display panel 243 of the present invention is attached are arranged. Also, the mounting holder 3
Eyepiece ring 3 having magnifying lens 305 inside 08
06 is arranged. Reference numeral 301 denotes a fluorescent light emitting tube, and the light emitted by the fluorescent light emitting tube 301 is emitted from a hole 303 in the central portion of the light shielding plate 302. The body 291, the mounting holders 307, 308, etc. are coated with black or dark colors on their inner surfaces in order to absorb unnecessary light. Incidentally. The fluorescent light emitting tube 301 may be replaced with a light emitting diode (LED).

By pulling the mounting holder 308 toward the observer, the mounting holder 307 is pulled, and the arrangement shown in FIG. 32 is obtained. FIG. 31 shows the state where the viewfinder is not used, that is, the state where the viewfinder is stored. In addition,
The mounting holders 307 and 308 may be integrally formed. FIG. 32 shows a state in which an image on the liquid crystal display panel is observed using the viewfinder. Figure 32
In this state, the focal point of the condenser lens 304 is set to the light emitting surface of the fluorescent light emitting tube 301. By moving the mounting holder 307 and the like, it is possible to reduce the volume of the viewfinder during storage and reduce the total length.

As an example, the diagonal length of the display area of the display panel 243 is 28 mm, the effective diameter of the condenser lens 304 is 30 mm, and the focal length is 15 mm. The condenser lens 304 is a plano-convex lens and has a flat surface facing the fluorescent light emitting tube 301 side. The condenser lens 304 and the magnifying lens 3
05 may be replaced with a Fresnel lens. If a Fresnel lens is used, the viewfinder volume can be reduced and the weight can be reduced.

Reference numeral 302 is a light shielding plate having a circular hole 303 in the center. It has a function of reducing the area where the light is emitted from the fluorescent light emitting tube 301 to a small area. When the area of the hole 303 is large, the display image on the display panel is bright, but the contrast is low. This is because the amount of light entering the condensing lens 304 increases, but the directivity of the incident light deteriorates.

The light emitted from the fluorescent light emitting tube 301 in a wide solid angle is converted into light with a narrow directivity by a condenser lens 304, and the light is incident from the counter electrode (not shown) side of the display panel 243. To do. The observer brings his or her eyes into close contact with the eyepiece cover 292 to see the display image on the display panel 243. That is, the position of the observer's pupil is almost fixed. Assuming that all pixels of the display panel 243 allow light to go straight, the condenser lens 304 is emitted from the fluorescent light emitting tube 301, and all the light incident on the effective area of the condenser lens 304 is transmitted through the magnifying lens 305. The light is incident on the observer's pupil. In this way, the observer can magnify and see the small display image on the display panel 243. In other words, you can see the enlarged virtual image.

Since the position of the observer's pupil in the viewfinder is substantially fixed by the eyepiece cover 292, the light source arranged behind it may have a narrow directivity. In a conventional viewfinder that uses a light box that uses a fluorescent tube as a light source, only light that travels within a minute solid angle in one direction from a region that is approximately the same size as the display region of the display panel is used, and in the other direction. The traveling light is not used. That is, the light utilization efficiency is very poor.

In the present invention, a light source having a small luminous body is used,
The light emitted from the light-emitting body in a wide solid angle is converted into nearly parallel light by the condenser lens 304. In this way, the light emitted from the condenser lens 304 has a narrow directivity. If the observer's viewpoint is fixed, the above-mentioned narrow directional light is sufficient for the viewfinder. If the size of the luminous body is small, naturally, the power consumption is also small. As described above, the viewfinder of the present invention utilizes that the observer views the displayed image with the viewpoint fixed. A normal direct-view display panel requires a certain viewing angle, but the viewfinder is sufficient as an application if the displayed image can be observed well from a predetermined direction.

Both the viewfinder and the video camera of the present invention are fixed to the video camera by the mounting brackets 293.

As shown in FIGS. 8 and 10, a mosaic color filter is attached to the display panel 243. The pixel arrangement is a so-called delta arrangement. The color filter transmits any color of red, green and blue. The film thickness of each color may be controlled by the composition of the color filter.
The film thickness of the color filter is adjusted and formed when the color filter is manufactured. That is, the thickness of the color filter is red,
Change with green and blue. The film thickness of the liquid crystal layer 17 on each pixel can be adjusted according to the color of each color filter by the film thickness of the color filter.

Further, as shown in FIG. 8, if a display panel in which a signal line is covered with a color filter is used, it is possible to prevent light leakage around the pixel. The condenser lens 304 is a plane,
That is, the surface having a large radius of curvature is directed toward the fluorescent light emitting tube 301 side. This is because it is easy to satisfy the sine condition and the brightness uniformity of the display image on the display panel 243 is improved.

By adjusting the insertion degree of the eyepiece ring 306 into the body 291, the focus can be adjusted according to the visual acuity of the observer. The eyepiece cover 29
Since the position of the observer's eyes is fixed by 2, the viewpoint position hardly changes during use of the viewfinder. If the viewpoint is fixed, the observer can see a good image even if the directivity of light to the display panel 243 is narrow. To make it look better, the emission direction of the light from the fluorescent light emitting tube 301 may be moved to an optimum direction.

FIG. 33 is a sectional view of a fluorescent light emitting tube used in the viewfinder of the present invention. As shown in FIG. 33, the fluorescent arc tube has a miniature bulb shape in appearance. 321
Is a case made of glass and has a diameter of 5 mm to 20 m.
m. 323 is a filament, DC 4V to 8
By applying a voltage of about V, the filament 323
To heat. 324 is an anode, and the applied voltage is DC 15 to 25V. The anode voltage accelerates the electrons emitted by heating the filament 323. Mercury molecules (not shown) are enclosed in the case 321, and the accelerated electrons emit ultraviolet rays by colliding with the mercury molecules. This ultraviolet ray excites the phosphor 322 to generate visible light. As such a light emitting element, there is a fluorescent light emitting tube (Lunalight 07 series) manufactured by Mini Pyro Electric Co., Ltd. The arc tube has a diameter of 7 mm, and is used by applying a direct current with a heater voltage of 5 V and an anode voltage of 23 V.

Driving is performed by pulse driving, so that the amount of emitted light can be adjusted. The pulse period is 30 hertz or more, preferably 60 hertz or more. By making the voltage applied to the anode a pulse signal, the amount of emitted light can be varied in proportion to the pulse width.

As shown in FIG. 33 (b), if a light shielding film 325 is formed on the case 321 to reduce the emission area of the light emitted from the light emitting element, the light shielding plate 302 as shown in FIG. 31 is necessary. No longer.

As described above, in the viewfinder of the present invention, the light emitted from the small light emitting element of the light emitting element in a wide solid angle is efficiently condensed by the condenser lens 304.
The power consumption of the light source can be significantly reduced as compared with the case of using a backlight of a surface light source using a fluorescent tube.

As the display device using the display panel of the present invention, the touch panel shown in FIG. 23 and the like, the projection type display device shown in FIG. 24 and the viewfinder shown in FIG. 30 are illustrated, but the present invention is not limited to this. Absent. For example, a display panel such as an electronic notebook, a display panel such as a pocket TV, a display panel of a mobile terminal, a display panel of a laptop personal computer, a reflective color display monitor, a video camera with a liquid crystal display panel (for example, Sharp (stock ) Has been released by the liquid crystal view cam) It is needless to say that it can be used for display monitors, image display panels for videophones, and display panels for head-mounted displays.

[0249]

The liquid crystal display panel of the present invention comprises a dielectric multilayer.
Since the film reflects specific visible light, it blocks as a BM.
It has a light function, but it can emit visible light like a conventional BM.
It absorbs and is not heated, and prolongs panel life.
Can be raised. In addition, adjacent pixel electrodes or
The dielectric constant of the dielectric pillars placed between the reflective electrodes is
Since it is smaller than the dielectric constant, lines of electric force pass through the liquid crystal layer.
And can prevent a lateral electric field between the reflective electrodes.
It

The projection-type display device of the present invention includes each display panel.
The dielectric multilayer film reflects the light incident on each display panel,
Since it functions as a BM, light leakage occurs around the pixel electrode.
It is possible to realize a high-quality display without causing any problems.

The viewfinder of the present invention is a light generating means.
The light emitting part of the
Power consumption is extremely low. In addition, the light generation means
Converts the light emitted from the step to parallel light and illuminates the display panel.
For clarity, the light intensity distribution of the illumination light is
Is set to the maximum and the light source image is not displayed.
A good display can be realized.

[0252]

[0253]

[0254]

[0255]

[0256]

[0257]

[0258]

[0259]

[0260]

[0261]

[0262]

[0263]

[0264]

[Brief description of drawings]

FIG. 1 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a display panel according to an embodiment of the present invention.

FIG. 3 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a display panel according to an embodiment of the present invention.

FIG. 5 is a plan view and a sectional view of a display panel according to an embodiment of the present invention.

FIG. 6 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 7 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 8 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram of a display panel according to an embodiment of the present invention.

FIG. 10 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 11 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 12 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 13 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 14 is a sectional view of a display panel according to an embodiment of the present invention.

15A is a plan view of a display panel according to an embodiment of the present invention. FIG. 15B is a cross-sectional view of the display panel according to an embodiment of the present invention.

FIG. 16 is a sectional view of a display panel according to an embodiment of the present invention.

17A is a plan view of a display panel according to an embodiment of the present invention. FIG. 17B is a cross-sectional view of the display panel according to an embodiment of the present invention.

FIG. 18 is a sectional view of a display panel according to an embodiment of the present invention.

19A is a plan view of a display panel according to an embodiment of the present invention. FIG. 19B is a cross-sectional view of the display panel according to an embodiment of the present invention.

FIG. 20 is a diagram showing a display panel in one embodiment of the present invention.

21A is a plan view of a display panel according to an embodiment of the present invention. FIG. 21B is a sectional view of the display panel according to an embodiment of the present invention.

22A is a plan view of a display panel according to an embodiment of the present invention. FIG. 22B is a cross-sectional view of the display panel according to an embodiment of the present invention.

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

FIG. 24 is a configuration diagram of a projection type display device in one embodiment of the present invention.

FIG. 25 is a configuration diagram of a projection type display device in one embodiment of the present invention.

FIG. 26 is a configuration diagram of a projection type display device in one embodiment of the present invention.

FIG. 27 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 28 is a configuration diagram of a projection type display device in one embodiment of the present invention.

FIG. 29 is an explanatory diagram of a display panel according to an embodiment of the present invention.

FIG. 30 is an external view of a display device (viewfinder) according to an embodiment of the present invention.

FIG. 31 is a sectional view of a display device (viewfinder) according to an embodiment of the present invention.

FIG. 32 is a sectional view of a display device (viewfinder) according to an embodiment of the present invention.

FIG. 33 is a cross-sectional view of a light emitting element used in the display device (viewfinder) of the present invention.

FIG. 34 is an explanatory diagram of the operation of the polymer dispersed liquid crystal.

FIG. 35 is a characteristic diagram showing an example of a dielectric multilayer thin film formed on the display panel of the present invention.

FIG. 36 is a characteristic diagram showing another example of the dielectric multilayer thin film formed on the display panel of the present invention.

FIG. 37 is a characteristic diagram showing another example of the dielectric multilayer thin film formed on the display panel of the present invention.

FIG. 38 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 39 is a sectional view of a display panel according to an embodiment of the present invention.

FIG. 40 is a perspective view of the optical system of the projection type display device in the embodiment of the present invention.

FIG. 41 is a configuration diagram of a projection display device according to an embodiment of the present invention.

FIG. 42 is a configuration diagram of a projection type display device in one embodiment of the present invention.

FIG. 43 is an explanatory diagram of a projection type display device in one embodiment of the present invention.

FIG. 44 is a configuration diagram of a projection type display device in one embodiment of the present invention.

FIG. 45 is an explanatory diagram of a projection type display device in one embodiment of the present invention.

FIG. 46 is a sectional view of a conventional display panel.

FIG. 47 is a sectional view of a conventional display panel.

[Explanation of symbols]

11 Counter substrate 12 Array substrate 13 Counter electrode 14 TFT 15 pixel electrodes 16 Dielectric multilayer film 17 Liquid crystal layer 18,51 Shading film 19 black beads 21 Source signal line 22 lines of electric force 23 Liquid crystal molecules 52 gate signal line 71 color filter 111 insulating film 121 reflective electrode 122 Connection 123 insulating film 124 Antireflection film 125 counter electrode 161 chassis 162 printed circuit board 163 connector 164, 151 shade pattern 171,176 Striped electrodes 172,212 Dielectric multilayer film 173,211 opening 174, 175, 214, 215 Electrode substrate 213 color filter 216 transparent electrode 217 Reflective electrode 218 LCD display panel 231 Transparent conductive sheet 232 analog switch 234 T-FF 235 inverter 236 switch 237 detection means 241 light source 241a lamp 241b concave mirror 241c UVIR cut filter 242,252,263 dichroic mirror 244 lens 245 aperture 246 Projection lens 247 relay lens 251,262 mirror 254, 264, 281 display panel 255,261 projection lens 265 optical axis 266 screen 267a Incident light 267b Emitted light 271 heat sink 272 adhesive 273 Drive IC 282 Optical binder 283 transparent substrate 284 concave lens 285 Light absorption film 286 Light emission surface 291 body 292 eyepiece cover 293 mounting bracket 301 Fluorescent tube 302 Light shield 303 hole 304 condensing lens 305 magnifying lens 307,308 Mounting holder 321 cases 322 phosphor 323 filament 324 anode 325 Light-shielding film 331 Water-drop liquid crystal 332 polymer 381 BM 382 alignment film 383 TN liquid crystal layer 384 Polarizer 391 Low dielectric pillar 411, 422, 423 Mirror 412 Projection lens 421 Projector 424 screen 425 cabinet 426 Auxiliary lens 431 container 432 Light absorption film 433 Optical wavelength limiting filter 434 Ethylene glycol liquid 435 Light entrance / exit surface 441 dichroic prism 442 Light separation surface

Continuation of front page (56) Reference JP-A-3-103830 (JP, A) JP-A-2-196221 (JP, A) JP-A-2-210329 (JP, A) JP-A-2-211402 (JP , A) JP-A-62-250416 (JP, A) Actual Kaihei 6-33140 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/1339 G02F 1/1333 G02F 1/1335 G02F 1/1343 G02F 1/1362 G02F 1/13 505 G03B 21/00

Claims (7)

(57) [Claims] A first substrate 1. A pixel electrode are arranged in a matrix, a second substrate on which the common electrode is formed, which is sandwiched between the first substrate and the second substrate a liquid crystal layer, wherein; and a placement dielectric pillars between the pixel electrode in contact next to the dielectric constant of the dielectric pillars is smaller than the dielectric constant of the liquid crystal layer, and the high of the dielectric pillars Is approximately equal to the film thickness of the liquid crystal layer, and the dielectric pillar is a dielectric multilayer film . A first substrate wherein pixel electrodes are arranged in a matrix, a second substrate on which the common electrode is formed, which is sandwiched between the first substrate and the second substrate A liquid crystal layer, a first dielectric pillar formed on the first substrate, and a second dielectric pillar formed on the second substrate, wherein the height of the first dielectric pillar is higher than that of the first dielectric pillar. And the height of the second dielectric pillar are approximately equal to the film thickness of the liquid crystal layer, and the dielectric constant of the dielectric pillar is smaller than the dielectric constant of the liquid crystal layer. > is rather, the dielectric pillars, the liquid crystal display panel, which is a dielectric multilayer film. A first substrate wherein the reflective electrode is arranged in a matrix, a second substrate on which the common electrode is formed, which is sandwiched between the first substrate and the second substrate a liquid crystal layer, comprising a dielectric film formed between the reflective electrode in contact next to the dielectric constant of the dielectric film, rather is smaller <br/> than the dielectric constant of the liquid crystal layer, the dielectric A liquid crystal display panel characterized in that the body pillar is a dielectric multilayer film . 4. A first array of pixel electrodes arranged in a matrix.
A first substrate, a liquid crystal layer sandwiched between the second substrate on which the common electrode is formed, the first substrate and the second substrate
And a dielectric film disposed between the adjacent pixel electrodes.
However, the dielectric constant of the dielectric film is smaller than that of the liquid crystal layer.
Fence, the dielectric film, <br/> liquid crystal display panel, which is a dielectric multilayer film. A liquid crystal display panel according to any one of claims 5] claims 1 to 4, an arc discharge lamp, an optical system for guiding light the arc discharge lamp is radiated to the liquid crystal display panel, the liquid crystal display A projection-type display device, comprising: a projection lens that magnifies and projects light modulated by a panel. 6. A liquid crystal display panel according to any one of claims 1 to 4, illuminating means for illuminating the liquid crystal display panel, viewed by an observer an enlarged light modulated by the liquid crystal display panel A viewfinder characterized by comprising a magnifying lens. 7. A liquid crystal display panel according to any one of claims 1 to 4 , a light generating means, and light emitted from the light generating means is converted into substantially parallel light to illuminate the liquid crystal display panel. And a magnifying lens for magnifying the light modulated by the liquid crystal display panel so that the light can be seen by an observer.