JP3209993B1 - Polymer dispersed liquid crystal display - Google Patents

Abstract

The present invention relates to a polymer-dispersed liquid crystal display device, in which a liquid crystal capsule is uniformly formed on the entire panel, and an excellent display performance is achieved. SOLUTION: A first substrate, a second substrate attached to the first substrate at an interval via an annular seal 50, and a liquid crystal arranged between the first and second substrates Layer 16
a liquid crystal display device comprising a liquid crystal capsule 46 in which the liquid crystal layer is dispersed in a polymer 44, wherein a liquid crystal insert for communicating the inside and the outside of the annular seal with the annular seal 50. An opening is provided, and a stopper 70 made of a photo-curable resin material that is cured by light of a first wavelength is disposed in the liquid crystal insertion opening.
It is a photocurable polymer material that is cured by light of a second wavelength different from the wavelength of.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polymer-dispersed liquid crystal display device in which liquid crystal molecules are randomly distributed so that incident light is scattered.

[0002]

2. Description of the Related Art A liquid crystal display device has a structure in which liquid crystal is inserted between a pair of substrates having transparent electrodes. The liquid crystal is generally used such that liquid crystal molecules are arranged in a certain direction. For example, in a twisted nematic liquid crystal display device,
A pair of substrates sandwiching the liquid crystal is rubbed in a direction perpendicular to the substrate, and the liquid crystal molecules are aligned along the rubbing direction of each substrate. On the other hand, there is a polymer dispersion type liquid crystal display device in which liquid crystal molecules are randomly distributed.

In a twisted nematic liquid crystal display device, since the liquid crystal molecules are oriented in a certain direction, the contrast of an image is reduced when the screen is viewed from a specific viewing angle direction related to the orientation direction of the liquid crystal molecules. It has been known. In a polymer dispersion type liquid crystal display device, a liquid crystal layer is composed of liquid crystal capsules dispersed in a polymer. In the liquid crystal capsule, liquid crystal molecules are phase-separated from the polymer little by little and condensed in a granular form, and the liquid crystal molecules are randomly distributed in the liquid crystal capsule. Since the liquid crystal molecules are randomly distributed in the polymer-dispersed liquid crystal display device, it is preferable because there is no specific viewing angle direction as in the case where the liquid crystal molecules are oriented in a certain direction.

In one example of the production of a polymer dispersed liquid crystal display device, a pair of substrates having transparent electrodes are adhered to each other with an annular seal, and a photocurable polymer material and a liquid crystal material are provided inside the annular seal between these substrates. And the polymer material is cured by irradiating light (for example, ultraviolet light) from the surface of one of the substrates. As the polymer material cures, the liquid crystal molecules phase-separate from the polymer little by little and condense in granular form to form liquid crystal capsules.

[0005]

In recent years, there has been an increasing demand for a liquid crystal display device to have a large screen, high definition, and color. Therefore, one substrate is provided with a color filter and a black matrix, and the other substrate is provided with an active matrix drive circuit. The active matrix driving circuit includes bus lines extending in a matrix. Small pixel electrodes are arranged in regions defined by these bus lines, and the pixel electrodes are connected to the bus lines via transistors (TFTs). ing.

In the manufacture of a polymer dispersed liquid crystal display device, when ultraviolet rays are irradiated to form a liquid crystal capsule by curing a photo-curable polymer material, the ultraviolet rays are conventionally irradiated vertically to the surface of the substrate. Was. However, in the case of a polymer dispersion type liquid crystal display device in which a black matrix is provided on one substrate and an active matrix driving circuit is provided on the other substrate, liquid crystal capsules are not uniformly distributed between these substrates. I understood that.

That is, the black matrix or the bus line is formed of a metal, and becomes a light shielding film when exposed to light. Therefore, no matter which substrate is irradiated with ultraviolet light, the ultraviolet light is not irradiated to the photocurable polymer material and the liquid crystal material under these light-shielding films. For this reason, the photocurable polymer located below these light-shielding films is not sufficiently cured, so that phase separation does not proceed and no liquid crystal capsule is formed. According to the observation, it was found that the region where the liquid crystal capsule was not formed extends not only at the position below the light-shielding film but also from the light-shielding film to the inside of the pixel region. For this reason, there is a portion without a liquid crystal capsule in the pixel region, and there is a problem that the contrast is reduced and the brightness in the bright state is reduced. In addition, when the stopper arranged at the liquid inlet of the annular meal is cured, the liquid crystal capsule may not be uniform.

An object of the present invention is to provide a polymer-dispersed liquid crystal display device in which liquid crystal capsules are uniformly formed over the entire panel and have excellent display performance.

[0009]

According to the present invention, there is provided a polymer-dispersed liquid crystal display device, comprising: a first substrate; a second substrate bonded to the first substrate at an interval via an annular seal; A liquid crystal layer disposed between the first and second substrates, wherein the liquid crystal layer includes a liquid crystal capsule dispersed in a polymer. A liquid crystal insertion port communicating between the inside and the outside of the annular seal is provided, and a plug made of a photocurable resin material that is cured by light of the first wavelength is arranged in the liquid crystal insertion port, and the polymer is It is a photocurable polymer material that is cured by light having a second wavelength different from the first wavelength.

[0010]

In the above construction, a plug made of a photo-curable resin material is arranged at the liquid crystal insertion port, and is irradiated with light of the first wavelength to cure the plug. At this time, the polymer in the polymer dispersed liquid crystal is not cured by the first light. The polymer is cured by light of the second wavelength. As a result, the liquid crystal capsule is uniformly formed on the entire panel. Therefore,
A polymer-dispersed liquid crystal display device having high contrast and brightness and excellent display performance can be obtained.

[0011]

FIG. 1 is a view showing a polymer dispersed liquid crystal display device 10 according to one embodiment of the present invention. This liquid crystal display device 10
Is a first substrate 12, a second substrate 14 opposed to the first substrate 12 at a small interval, and a liquid crystal inserted between the first and second substrates 12, 14. And a liquid crystal panel comprising the layer 16.

As shown in FIG. 3, a polarizer 18 and an analyzer 20 can be arranged on both sides of the liquid crystal panel. In this case, since it is a transmissive liquid crystal display device, the first and second substrates 12 and 14 are transparent glass substrates. The polarizer 18 and the analyzer 20 are arranged such that the absorption axes of polarized light are orthogonal to each other.

Alternatively, as shown in FIG. 4, a color layer 22 and a reflection layer 24 can be provided on the first substrate 12. In this case, since it is a reflection type liquid crystal display device,
The second substrate 14 is a transparent glass substrate, while the first substrate 12 is an opaque glass substrate. In FIG.
Further, a transparent layer 26 is provided between the liquid crystal layer 16 and the color layer 22 so as to keep a distance between the color layer 22 and the liquid crystal layer 16.

In FIG. 1, a transparent electrode 28 is provided on the inner surface of the first substrate 12, and a transparent electrode 30 is provided on the inner surface of the second substrate 14. In the embodiment, the transparent electrode 28 is a pixel electrode having a small area, and the transparent electrode 3
0 is a common electrode. The transparent electrodes 28 and 30 are made of ITO (In
₂ O ₃ -SnO ₂ ).

The transparent electrode 28 as a pixel electrode is connected to an active matrix driving circuit. As shown in FIG. 2, the active matrix driving circuit includes a gate bus line 32, a drain bus line 34, and a transistor (TFT) 36 extending in a matrix.
Are connected to the gate bus line 32 and the drain bus line 34 via the transistor 36. A storage capacitor electrode 38 is provided below the transparent electrode 28 via an insulating layer (not shown).

A color filter 40 and a black matrix 42 are provided below the transparent electrode 30 on the inner surface of the second substrate 14. The black matrix 42 has an opening for opening each color portion of the color filter 40. The black matrix 42, the gate bus line 32, and the drain bus line 34 are made of metal and serve as a light shielding film for light.

The liquid crystal layer 16 includes a liquid crystal capsule 46 dispersed in a polymer 44. The liquid crystal capsule 46 is made of, for example, a p-type nematic liquid crystal. The polymer 44 is made of, for example, an ultraviolet curable resin such as a polymethyl methacrylate (PMMA) resin. As shown in FIG. 1, in the present invention, the liquid crystal capsule 46 includes the first and second substrates 12 and 1.
The light-shielding layer (for example, black matrix 42) and its opening portion (for example, each color portion of the color filter 40) are located between 4
And is almost uniformly distributed over.

The operation of the polymer dispersion type liquid crystal display device is as follows. As shown in FIG. 3A, when no voltage is applied (when the applied voltage V is smaller than the threshold voltage V ₀ )
The liquid crystal molecules 48 in the liquid crystal capsule 46 are randomly distributed. Therefore, the polarized light passing through the polarizer 18 scatters on the liquid crystal molecules 48 in the liquid crystal capsule 46. Part of the scattered light can pass through the analyzer 20. Therefore, in this case, white display is performed.

As shown in FIG. 3B, when a voltage is applied (when the applied voltage V is larger than the threshold voltage V ₀ ), the liquid crystal molecules 48 in the liquid crystal capsule 46 are perpendicular to the substrate surface. stand up. The polarized light passing through the polarizer 18 passes through the liquid crystal molecules 48 in the liquid crystal capsule 46 and strikes the analyzer 20 while maintaining its vibration surface. The analyzer 20 is the polarizer 1
Since the absorption axis 8 and the absorption axis are arranged orthogonally, polarized light passing through the polarizer 18 cannot pass through the analyzer 20. Therefore, in this case, black display is performed.

In the case of the reflection type shown in FIG. 4, (A)
(When the applied voltage V is equal to the threshold voltage V
_When it is smaller than ₀ ), the liquid crystal molecules 48 in the liquid crystal capsule 46 are randomly distributed. Accordingly, the incident light impinges on the liquid crystal molecules 48 in the liquid crystal capsule 46 and is scattered. In this case, white display is obtained by scattering. At this time, if there is a thick transparent body layer 26, the color layer 22 cannot be directly seen at the time of scattering.

As shown in FIG. 4B, when a voltage is applied (when the applied voltage V is larger than the threshold voltage V ₀ ), the liquid crystal molecules 48 in the liquid crystal capsule 46 are perpendicular to the substrate surface. stand up. Therefore, the liquid crystal layer 16 becomes transparent, and the color layer 22 can be seen. When the color layer 22 is black, black display is performed. The color layer 22 may have another color.

As described above, in the production of the polymer dispersion type liquid crystal display device having the liquid crystal layer 16 including the liquid crystal capsule 46, the material of the photocurable polymer 44 and the liquid crystal material 48 are used.
And preparing a mixture thereof with the first and second substrates 12,
14, the polymer 44 is cured by irradiating ultraviolet rays from one of the substrates (12 or 14), so that the polymer 44 and the liquid crystal 48 undergo phase separation and are dispersed in the polymer 44. A capsule 46 is formed.

As shown in FIG. 5, when ultraviolet rays are irradiated from one of the substrates (for example, 14), the ultraviolet rays are naturally applied to the surface of the substrate 14 at right angles. Therefore, the black matrix 42 serves as a light-shielding film, and the mixture 16a of the material of the photocurable polymer 44 and the liquid crystal material 48 under the black matrix 42 is not irradiated with ultraviolet rays. 44 does not cure sufficiently, so that phase separation does not proceed, and the liquid crystal capsule 46 is not formed.

FIG. 6 is a diagram showing the distribution of the liquid crystal capsules 46 in this case. The liquid crystal capsule 46 is not located in the area covered by the black matrix 42 but only in the area covered by the color filter 40 which is the opening. In addition, there is no liquid crystal capsule 46 in the peripheral area of the area covered by the color filter 40. Therefore, there is a problem that the contrast is reduced and the brightness in the bright state is reduced. When the other substrate 12 is irradiated with ultraviolet light, the gate bus line 32 and the drain bus line 34
Is a light-shielding film.

As shown in FIG. 7, in a preferred embodiment of the present invention, when ultraviolet light is irradiated from one substrate (for example, 14), light is obliquely applied to the surface of the substrate 14 with respect to the surface. Irradiation. At the beginning of the manufacturing process, as is known, the liquid crystal layer 16 of the polymer dispersion type liquid crystal display device of the present invention comprises the first and second substrates 1 and 2.
2 and 14 are bonded together by an annular seal 50 (see FIG. 9), and an annular seal 5 between the first and second substrates 12 and 14 is provided.
0 and the liquid crystal 48 and the material of the photocurable polymer 44
Of the mixture 16a with the above material is inserted.

Then, as shown in FIG. 7, the surface of the substrate 14 having the black matrix 40 (or bus line) serving as a light-shielding layer for curing the material of the polymer 44 is obliquely oblique to the surface. Irradiate light. The material of the polymer 44 is cured by the irradiation of the ultraviolet rays, and at that time, the material of the polymer 44 and the material of the liquid crystal 48 undergo phase separation. By this phase separation, the liquid crystal capsule 4 dispersed in the polymer 44
6 are formed.

As described above, by irradiating the surface of the substrate 14 with the ultraviolet light in an oblique direction, the ultraviolet light is transmitted obliquely through the substrate 14 and is also applied to the region below the black matrix 40 (or the bus line) serving as a light shielding layer. Can be reached. In this case, as shown by a solid arrow in FIG.
There is a shaded part of 0. Therefore, in addition to irradiation from the direction of the solid arrow, as indicated by the dashed arrow,
When ultraviolet light is irradiated from other directions, the shade of the black matrix 40 disappears, and the mixture 16a of all the materials of the polymer 44 and the material of the liquid crystal 48 is irradiated with the ultraviolet light. And the phase separation proceeds, and the liquid crystal capsules 46 are formed in all the regions.

FIG. 8 is a view showing the distribution of the liquid crystal capsules 46 thus formed. The liquid crystal capsules 46 are distributed almost uniformly in a region covered by the black matrix 42 and in a region covered by the color filter 40 which is an opening thereof, that is, almost all over the liquid crystal panel. When the other substrate 12 irradiates ultraviolet rays, the gate bus lines 32 and the drain bus lines 34 become light-shielding films, but the ultraviolet rays reach below the bus lines 32 and 34.

As shown in FIG. 7, when the substrate 14 is irradiated with ultraviolet rays in the air, the ultraviolet rays are refracted on the surface of the substrate 14. In the present invention, the refraction angle of the substrate 14 is reduced.
Must be oblique to the surface of the object. In the law of refraction, the angle of incidence> the angle of refraction, and the angle of incidence must be such that the angle of refraction does not become 90 degrees. Therefore, the incident angle should be about 45 degrees or more, and the ultraviolet rays should be incident on the surface of the substrate 14 as close as possible. UV light on substrate 1
In order to make the light beam 4 uniform, it is preferable that the light beam is incident as parallel rays as much as possible.

FIG. 9 shows one substrate 1 using a transparent plate 52.
FIG. 4 is a diagram illustrating an example of irradiating ultraviolet rays from No. 4; The transparent plate 52 is made of quartz glass that transmits ultraviolet light, and has a thickness of, for example, about 50 mm. The thickness of the liquid crystal layer 16 is about 5 to 20 μm, and the thickness of the substrates 12 and 14 is about 1.1 mm. FIG. 9 shows end portions of the glass substrates 12 and 14,
The glass substrates 12 and 14 are bonded together with an annular seal 50 extending annularly along the outer edges of the glass substrates 12 and 14.

As described above, the ultraviolet light should be incident on the surface of the substrate 14 at an angle as close as possible. However, when the ultraviolet light is obliquely incident on the surface of the substrate 14, the ratio of reflection on the surface of the substrate 14 increases. In FIG. 9, ultraviolet rays are incident on the end face of the transparent plate 52. The incident angle of the ultraviolet light on the end face of the transparent plate 52 is small, that is, the ultraviolet light is obliquely incident on the end face of the transparent plate 52 at an angle close to perpendicular. Therefore, the reflection of the ultraviolet light on the end face of the transparent plate 52 can be reduced. Further, since the incident angle of the ultraviolet light on the end face of the transparent plate 52 is small, the refraction angle is also small. Therefore, the UV light is
4 can be made to enter the surface as close as possible. The angle formed by the surface of the substrate 14 when the ultraviolet rays travel inside the substrate 14 is indicated by α. Should be less than 45 degrees, and preferably less than about 10 degrees.

In FIG. 9, a coupling oil layer 54 is inserted between the transparent plate 52 and the substrate 14. The coupling oil layer 54 has a refractive index higher than that of air, preferably has a refractive index of the transparent plate 52 and a refractive index of the substrate 14, and has a transparent refractive index between the transparent plate 52 and the substrate 14. This is made closer to the plate 52 and the substrate 14. An immersion oil manufactured by Olympus Optical can be used as such a coupling oil.

If there is no coupling oil layer 54, a slight air layer may be formed between the transparent plate 52 and the substrate 14. If there is an air layer below the transparent plate 52, the light reaching the lower surface of the transparent plate 52 is totally reflected as indicated by the dashed arrow a. In order to prevent such total reflection, a coupling oil layer 54 is preferably inserted between the transparent plate 52 and the substrate 14.
What is inserted for this purpose is not limited to the oils mentioned above. Any liquid or paste-like material that fills the gap between the transparent plate 52 and the substrate 14 and is transparent and has a desired refractive index larger than air can be used. A preferred material other than oil is, for example, silicone rubber.

FIG. 10 is a diagram showing the arrangement of the light sources in the configuration of FIG. The liquid crystal display device 10 with the mixture 16a of the material of the uncured polymer 44 and the material of the liquid crystal 48 inserted between the first and second substrates 12 and 14 is a table 5.
6 and a transparent body 52 is placed on the liquid crystal panel 10a. The light sources 58a, 58b, 58c, 58d each comprising a long lamp and a concave mirror are provided on the liquid crystal panel 10a.
Are arranged in parallel to each side. Each light source 58a, 58b, 5
8 c and 58 d are arranged toward the end face of the transparent plate 52, and the ultraviolet light incident on the end face of the transparent plate 52 obliquely enters the substrate 14 through the transparent plate 52 and cures the material of the polymer 44. In this case, since the ultraviolet rays enter from four directions, there is no place behind the black matrix 42 and the bus lines 32 and 34.

FIG. 11 is a diagram showing another example of the arrangement of the light sources. In this example, the liquid crystal panel 10a is placed on a table 56, and the transparent body 52 is placed on the liquid crystal panel 10a. Light sources 58 each comprising a long lamp and a concave mirror
a and 58b are arranged at adjacent corners of the liquid crystal panel 10a at an angle of 45 degrees on each side. Each light source 58a, 58b
Are arranged toward the end face of the transparent plate 52,
UV light incident on the end face of the substrate 14 passes through the transparent plate 52 and
At an angle to cure the polymer 44 material. Also in this case, since the ultraviolet rays are incident from two directions, there is no place behind the black matrix 42 and the bus lines 32 and 34. Note that the two light sources 58a and 58b can be arranged at positions facing each other.

In FIG. 11, the table 6
A cooling water circuit having a zero and an outlet 62 is formed. By cooling the table 56 in this manner, the substrates 12, 14 of the liquid crystal display device 10 are prevented from being heated by the irradiation of ultraviolet rays. Also in FIG. 9, a cooling water circulation path is formed.

FIG. 12 is a diagram showing an example of a light source. The light source includes a long lamp 58x, a concave mirror 58y partially covering the lamp 58x, and a convex lens 58z.
This arrangement is merely an example of obtaining a light beam as parallel as possible, and it is preferable to irradiate the material of the polymer 44 with the light beam as parallel as possible.

FIG. 13 shows the first and second substrates 12 and 14.
FIG. 7 is a diagram showing an example of a process after bonding the slabs with an annular seal 50. The first and second substrates 12 and 14 are formed with transparent electrodes 28 and 30 (FIG. 1), respectively, and the annular seal 50 has a liquid crystal insertion port 64.

The liquid crystal is inserted into the annular seal 50 between the first and second substrates 12 and 14 from the liquid crystal insertion port 64. Usually, the insertion of the liquid crystal is performed in a negative pressure container. The liquid crystal is contained in a small liquid crystal container inside the negative pressure container. First, the bonded first and second substrates 12 and 14 are placed in a negative pressure container, and the inside of the annular seal 50 is evacuated. Then, the liquid crystal insertion port 64 is immersed in the liquid crystal of the liquid crystal container, and then the atmosphere is introduced into the negative pressure container. Then, the liquid crystal enters the inside of the annular seal 50 between the first and second substrates 12 and 15 due to a capillary phenomenon and a pressure difference. When the liquid crystal is inserted into the inside of the annular seal 50 between the first and second substrates 12, 14, the first and second substrates 12, 14 have a shape bulging out beyond a predetermined interval.

Therefore, as shown in FIG. 13A, the first and second substrates 12 and 14 are
68, pressure P is applied from both sides, and the first and second
Between the substrates 12 and 14 at predetermined intervals.
In this case, if one plate 66 is, for example, the table 56 in FIGS. 10 and 11, and the other plate 68 is, for example, the transparent plate 52 made of quartz glass in FIGS. It can be carried out. In this case, since the transparent plate 52 has a considerable thickness, the weight is heavy, and the pressure P can be applied by the weight of the transparent plate 52. Thus, when a predetermined interval is established between the first and second substrates 12 and 14, the liquid crystal insertion port 64 is closed with the stopper 70 as shown in FIG.

FIG. 14 is a sectional view for explaining the formation of the plug 70 in detail. Each drawing is a cross-sectional view as viewed in the direction of the first substrate 12 along the intermediate plane of the annular seal 50. (A)
Shows a state in which a mixture 16a of a material of a UV-curable polymer 44 and a material of a liquid crystal 48 is inserted between the first and second substrates 12 and 14. First and second substrates 12, 1
The interval of 4 is set as shown in FIG.

FIG. 14B shows that the liquid crystal insertion port 64 is
Indicates the closed position. In this embodiment, the stopper 70
Is made of a photocurable material, which is cured by light having a wavelength that does not cure the polymer 44 in the mixture 16a. For example, the polymer 44 in the mixture 16a cures with ultraviolet light, whereas the material of the plug 70 cures with visible light. The polymer 44 in the mixture 16a does not cure with visible light. For example, the material of the stopper 70 is LCR manufactured by ICI of the United Kingdom.
0242D can be used. This is 480nm
Cured by light of the above wavelength.

(C) shows a state where the stopper 70 is irradiated with visible light. Thereby, the stopper 70 is completely hardened, and the inside of the annular seal 50 is completely closed. However, upon irradiation with visible light, the polymer 44 in the mixture 16a is not cured at all. Thus, the polymer 4 in the mixture 16a
4 is completely unaffected by the radiation for curing the stopper 70.
If the polymer 44 in the mixture 16a is partially cured by being affected by irradiation for curing the stopper 70, the liquid crystal capsule 46 may not be formed uniformly thereafter. Finally, as shown in (D), the polymer 44 is cured while irradiating the ultraviolet light obliquely, and the liquid crystal capsule 46 is uniformly formed by phase separation.

FIG. 15 is a diagram showing a modification of the liquid crystal display device 10 shown in FIG. In FIGS. 3 and 15, an absorption axis 18 a is provided outside the first and second substrates 12 and 14.
The polarizer 18 and the analyzer 20 are arranged so that 20a is orthogonal. In such a configuration, as shown in FIG. 3B, when the voltage is turned on, the liquid crystal molecules 48 in the liquid crystal capsule 46 stand perpendicular to the substrate surface, and the polarized light passing through the polarizer 18 is reflected by the analyzer 20. And the display becomes black. However, light obliquely incident on the polarizer 18 transmits obliquely through the liquid crystal molecules 48 in the liquid crystal capsule 46, and is subjected to the action of birefringence to change the vibration plane. Therefore, a part of the light is
And there is a problem that leakage light is generated at the time of black display.

In order to solve this, in FIG. 15, a first film 72 having an in-plane refractive index anisotropy and a in-plane refractive index between the polarizer 18 and the analyzer 20 are shown in FIG. A second film 74 isotropic and has a refractive index anisotropy in the vertical direction. In an embodiment, the first film 72 is between the first substrate 12 and the polarizer 18 and the second film 74 is between the second substrate 14 and the analyzer 20. The first and second films 72, 74 may be reversed.

The first film 72 is a uniaxially stretched retardation film, for example, polyvinyl alcohol (PVA),
Alternatively, it is obtained by stretching polyethylene terephthalate (PET) in a certain direction. The first film 72 is arranged such that its stretching axis 72a coincides with one optical axis (absorption axis) of the polarizer 18 and the analyzer 20.

The second film 74 has a negative uniaxial refractive index anisotropy, for example, polyvinyl alcohol (PV).
A) is obtained by two-dimensional stretching. FIG. 16 shows ellipsoids of the refractive indices of the second film 74 and the p-type nematic liquid crystal, and the refractive indices in the three axial directions are indicated by n _x , n _y , and n _z .

[0048] (A) shows the ellipsoid of refractive index of the second film 74, a relationship of this _{case, n X = n Y> n} Z. (B) shows an ellipsoid of the refractive index of the p-type nematic liquid crystal, and the state where the liquid crystal molecules 48 stand as shown in (B) of FIG. 3 corresponds to this. p-type state nematic liquid crystal stood in the relation of _{n X = n Y <n Z} . Thus, the second
When the film 74 of FIG.
When the optical actions of the respective birefringences cancel each other out and the light travels obliquely, the above-described leaked light can be prevented.

However, the effect of preventing leakage light is due to the polarizer 18.
When viewed from a direction along the direction of the absorption axis 18a of the analyzer 20 and the absorption axis 20a of the analyzer 20,
This is different from the case of viewing from a direction rotated by 45 degrees with respect to the direction of 0a. The first film 72 reduces the variation in the effect of preventing the leakage light due to such a viewing angle rotation angle as described below.

FIG. 17 shows a case where the liquid crystal display device 10 is viewed from an oblique direction forming a viewing angle inclination X and a viewing angle rotation angle Y with respect to a normal line N. In FIG. 17, 18a, 20
a is the absorption axis 18a of the polarizer 18 and the analyzer 20
Are moved in parallel with the absorption axis 20a.

FIG. 18 shows a view angle in the case where the view angle inclination angle X from the absorption axis 18a of the polarizer 18 (or the absorption axis 20a of the analyzer 20) is 0 degree, when the viewing angle inclination X in FIG. The directions are indicated by arrows P, and similarly, the viewing angle directions when the viewing angle rotation angle Y is 45 degrees are indicated by arrows Q, respectively.

FIG. 19 is a view showing black display characteristics when four polymer dispersed liquid crystal display device samples are prepared, and these four samples are arranged side by side and viewed from each viewing angle direction.
Sample 10 _0, first and second films 72, 74
This is the configuration of FIG. Sample 10 _A is a configuration in which only the second film 72 is. Sample _10B is
In this configuration, only the first film 72 is provided. Sample 1
0 _AB , FIG. 1 with the first and second films 72, 74
5 is provided.

FIG. 19A shows that four samples are plotted on a normal line N.
It shows the case viewed from the direction of. In this case, good black display can be obtained for all four samples. (B) shows a case where four samples are viewed from the P direction. In this case, good black display can be obtained for all four samples. (C) shows a case where four samples are viewed from the Q direction. In this case, the sample 10 _AB can obtain a good black display, but the other samples have black gray due to leaked light. Sample 10 _A is prevented to some extent leakage light, but the sample 10 ₀ and 10 _B it can be seen that there is considerable leakage light. That is, sample 1
0 _AB has a good light leakage prevention effect.

[0054]

As described above, according to the present invention,
Since the liquid crystal capsule is uniformly formed on the entire panel, a polymer-dispersed liquid crystal display device having high contrast and brightness and excellent display performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a partially enlarged plan view showing the TFT substrate of FIG.

FIG. 3 is a diagram illustrating the operation of the liquid crystal display device of FIG.

FIG. 4 is a diagram illustrating an example of a reflective liquid crystal display device.

FIG. 5 is a diagram showing an example of ultraviolet irradiation.

FIG. 6 is a view showing distribution of liquid crystal capsules by irradiation in FIG. 5;

FIG. 7 is a diagram illustrating an example of ultraviolet irradiation.

FIG. 8 is a diagram showing distribution of liquid crystal capsules by irradiation in FIG. 7;

FIG. 9 is a diagram illustrating an example of irradiating ultraviolet rays using a transparent plate.

FIG. 10 is a diagram showing an arrangement of the light sources in FIG. 9;

FIG. 11 is a diagram showing another example of the arrangement of the light sources.

FIG. 12 is a diagram illustrating an example of a light source that obtains a parallel light beam.

FIG. 13 is a view showing a process after bonding the substrates.

FIG. 14 is a view showing the formation of a plug in the step of FIG.

FIG. 15 is a diagram showing a modification of the apparatus shown in FIG. 3;

FIG. 16 is a diagram showing an ellipsoid of a refractive index of the second film of FIG. 15 and a liquid crystal.

FIG. 17 is a diagram illustrating a case of viewing from an oblique viewing angle direction.

18 is a diagram showing a case where FIG. 17 is viewed in a plan view.

FIG. 19 is a diagram showing a leakage light prevention effect of the configuration of FIG. 15;

[Explanation of symbols]

 12, 14 ... substrate 16 ... liquid crystal layer 18 ... polarizer 20 ... analyzer 28, 30 ... transparent electrode 32, 34 ... bus line 36 ... transistor 40 ... color filter 42 ... black matrix 44 ... polymer 46 ... liquid crystal capsule 50 ... Annular seal 64 ... Liquid crystal insertion port 70 ... Stopper

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideaki Tsuda 1015 Uedanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Yasuo Yamagishi 1015 Kamikodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited ( 72) Inventor Shin Eguchi 1015 Ueodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (56) References JP-A-4-350622 (JP, A) JP-A-5-203928 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1334 G02F 1/1341

Claims (2)

(57) [Claims] A first substrate, a second substrate attached to the first substrate at an interval via an annular seal,
A liquid crystal display device comprising a liquid crystal layer disposed between the first and second substrates, wherein the liquid crystal layer includes a liquid crystal capsule dispersed in a polymer. A liquid crystal insertion port communicating the inside and the outside of the annular seal is provided, and the liquid crystal insertion port is
A plug made of a photocurable resin material that is cured by light of a first wavelength is disposed, and the polymer is a photocurable polymer material that is cured by light of a second wavelength different from the first wavelength. A polymer-dispersed liquid crystal display device. 2. The polymer dispersion type according to claim 1, wherein the photocurable resin material is a material that cures with visible light, and the photocurable polymer material is a material that cures with ultraviolet light. Liquid crystal display.