JP2000284262A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device having excellent display quality by controlling the interfacial regulating force and decreasing optical hysteresis as much as possible. SOLUTION: This liquid crystal display device has such a structure that a liquid crystal polymer composite layer 4 containing liquid crystal drops 12, 13 and a polymer resin 11 is disposed between a pair of substrates 2, 3 having electrodes 6, 9, respectively. Relating to this device, insulating films 7, 10 are formed on the electrodes 6, 9, respectively, and the critical surface tension γAL of the insulating films 7, 10 and the critical surface tension γP of the polymer resin satisfy the relation of γAL>γP.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device using polymer dispersed liquid crystal in which liquid crystal is dispersed and held in a polymer resin matrix.

[0002]

2. Description of the Related Art In recent years, a polymer dispersed liquid crystal (PDLC) in which a nematic liquid crystal is dispersed and held in a polymer having the same refractive index as liquid crystal molecules is sandwiched between a pair of upper and lower substrates having electrodes. A liquid crystal display element that changes the refractive index of liquid crystal depending on the presence or absence of an electric field and switches between a scattering state and a transmission state has attracted much research and developers' attention (Japanese Patent Application Laid-Open No. Sho 60-252687).

The display principle of such a polymer-dispersed liquid crystal display device will be described below.

When no voltage is applied, as shown in FIG. 3 (a), the molecular axis of the liquid crystal 24 is oriented in a random direction, so that the refractive index of the liquid crystal region is different from that of the surrounding polymer phase 25. The incident light 22 entering the display element becomes scattered light 23, and as a result, a scattered state is obtained. On the other hand, the transparent electrode 2
When an electric field is applied to the liquid crystal 2 as shown in FIG.
4 are arranged in the direction of the electric field, and the refractive index of the liquid crystal region is increased with respect to the surrounding polymer phase 25 for light incident perpendicularly to the substrate.
Since the refractive index substantially coincides with the refractive index, the light is not scattered and becomes the transmitted light 26. As a result, a transmission state is obtained.

The liquid crystal display device using the polymer-dispersed liquid crystal utilizes light scattering, so that there is no need to use a polarizing plate. Unlike a conventional twisted nematic (TN) liquid crystal display device, In order to obtain linearly polarized light, it is brighter than a liquid crystal optical element that must use a polarizing plate,
Display with a wide viewing angle becomes possible.

[0006]

However, in the above-mentioned liquid crystal display device using the polymer-dispersed liquid crystal, the applied voltage-
A problem has been that optical hysteresis in light transmittance characteristics is large and display quality is significantly impaired. FIG.
With reference to FIG.

It is considered that the optical hysteresis characteristic of the polymer dispersed type liquid crystal display element is related to a regulating force acting on the liquid crystal / polymer matrix interface (hereinafter, referred to as an interface regulating force). This interface regulating force acts as a force that causes the liquid crystal molecules arranged in the direction of the electric field to transition to the original random arrangement state when the electric field is turned off.
When this force is weak, the transition of the liquid crystal molecules hardly occurs particularly near the liquid crystal / polymer matrix interface. Therefore, the state where the transmittance of the liquid crystal display element is large is maintained. As a result, the voltage-transmittance characteristic has a large optical hysteresis as shown by the line b in FIG. On the other hand, when the interface regulation force is strong, the transition of the liquid crystal molecules near the interface easily occurs, and the change in the transmittance of the liquid crystal display element is smooth, and as shown by the line a in FIG.
The optical hysteresis in the transmittance characteristics is small. Therefore, it is understood that according to the above-mentioned mechanism, in order to reduce the optical hysteresis, the interface regulating force should be increased. However, at present, there is no precise means for controlling the interface regulating force. Therefore, there has been a demand for a liquid crystal display element that controls the interface regulating force to reduce optical hysteresis.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display device having excellent display quality by controlling the interface regulating force so as to reduce optical hysteresis as much as possible.

[0009]

In order to achieve the above object, according to the present invention, there is provided a liquid crystal polymer composite comprising a liquid crystal and a polymer resin between a pair of substrates each having an electrode. In a liquid crystal display device having a structure in which layers are arranged, an insulating film is provided on the electrode, and the critical surface tension of the insulating film is γ _AL , and the critical surface tension of the polymer matrix is γ _P , Γ _AL and γ _P satisfy the relationship of the following equation (1).

(Equation 4)

[0010] With the above configuration, the polymer resin is easily wetted on the insulating film. As a result, hemispherical liquid crystal droplets (see FIG. 1) in contact with the insulating film are formed. In such an environment,
The liquid crystal molecules receive a strong alignment regulating force from the substrate interface, and this regulating force works to assist the interface regulating force at the liquid crystal / polymer resin interface. The transition in the drop occurs smoothly and the optical hysteresis is reduced.

[0011] According to a second aspect of the invention, in the liquid crystal display device according to claim 1, wherein, when the surface tension of the liquid crystal was set to gamma _LC, gamma _AL and gamma _LC satisfies the following relationship formula (2) It is characterized by the following.

(Equation 5)

With the above structure, the liquid crystal is easily wetted, so that the liquid crystal molecules in the hemispherical liquid crystal droplet in contact with the insulating film are aligned substantially parallel to the substrate (see FIG. 2A). This allows
In addition to reducing optical hysteresis, scattering performance is improved.

[0013] According to a third aspect of the invention, in the liquid crystal display device according to claim 1, wherein, when the surface tension of the liquid crystal was set to gamma _LC, gamma _AL and gamma _LC satisfies the following relationship formula (3) It is characterized by the following.

(Equation 6)

With the above structure, the liquid crystal is hardly wetted, so that the liquid crystal molecules in the hemispherical liquid crystal droplet (see FIG. 1) in contact with the insulating film are oriented substantially perpendicular to the substrate (see FIG. 2 (b)).
Thereby, the electric field response is improved in addition to the reduction of the optical hysteresis.

[0015]

FIG. 1 is a simplified cross-sectional view of a liquid crystal display device 1 according to an embodiment of the present invention. The liquid crystal display element 1 includes an array substrate 2, a counter substrate 3 disposed to face the array substrate 2, and a liquid crystal / polymer composite layer 4 disposed between the array substrate 2 and the counter substrate 3. Have. The array substrate 2 and the counter substrate 3 are transparent substrates made of, for example, glass. On the array substrate 2, a thin film transistor (TFT) as a pixel switching element, a metal wiring (scanning signal line / image signal line), a transparent pixel electrode 6, and the like are formed. These metal wiring, TFT, pixel electrode 6 and the like are covered with an insulating film 7. It should be noted that in FIG. 1, metal wiring and T
FT and the like are omitted.

A transparent counter electrode 9 is formed on the inner surface of the counter substrate 3, and the counter electrode 9 is covered with an insulating film 10. The pixel electrode 6 and the counter electrode 9
Is made of, for example, ITO (indium tin oxide).

The liquid crystal / polymer composite layer 4 is basically a polymer dispersed liquid crystal (PDLC) layer having a structure in which liquid crystal droplets are independently dispersed in a polymer resin matrix. However, the liquid crystal / polymer composite layer 4 in the present embodiment is
Unlike ordinary polymer dispersed liquid crystal layers, polymer resin 11
And two types of liquid crystal droplets 12 and 13.
The liquid crystal in the liquid crystal droplets 12 and 13 has a positive dielectric anisotropy. The liquid crystal droplet 12 is a liquid crystal / polymer composite layer 4
It exists inside and is formed in a substantially spherical shape like liquid crystal droplets in a normal polymer dispersed liquid crystal layer. On the other hand, the liquid crystal droplet 13 exists on each of the insulating films 7 and 10 and is formed in a dome shape protruding inward of the liquid crystal / polymer composite layer 4. More specifically, the liquid crystal droplet 13 is formed on the insulating films 7 and 1.
It is formed in a hemisphere in which a great circle is in contact with 0 or a flat hemisphere. The liquid crystal / polymer composite layer 4 is not limited to a polymer dispersed liquid crystal (PDLC) layer, but may be a polymer network type liquid crystal layer in which a liquid crystal is held in a three-dimensional network polymer.

The array substrate 2 and the opposing substrate 3 are bonded together by the spacer / seal resin 15, and the liquid crystal / polymer composite layer 4 is sealed.

Here, the materials of the insulating films 7 and 10 are selected such that the material satisfies the following equation (1).

(Equation 7)

In the equation (1), γ _AL is the insulating film 7, 10
Denotes the critical surface tension, and γ _P denotes the critical surface tension of the polymer resin 11. Insulating films 7, 1 satisfying such conditions
The use of 0 is a feature of the present invention,
Thereby, a dome-shaped liquid crystal droplet 13 can be formed, and as a result, optical hysteresis can be reduced. Hereinafter, this reason will be described in detail.

We aimed to adjust the interfacial regulation force, and performed experiments focusing on the balance of the surface energy in the vicinity of the array substrate 2 and the opposing substrate 3 sandwiching the liquid crystal / polymer composite layer 4. It has been found that there is a certain correlation between the critical surface tension of the substrate and the critical surface tension of the polymer resin and the optical hysteresis. That is, it was found that the hysteresis was extremely small when the critical surface tension of the substrate was higher than the critical surface tension of the polymer resin.
As the critical surface tension of the substrate, specifically, various insulating films having different critical surface tensions were formed on the substrate to change the critical surface tension of the substrate. Therefore, in other words, when the critical surface tension γ _AL of the insulating films 7 and 10 is larger than the critical surface tension γ _P of the polymer resin 11, the hysteresis becomes extremely small. It is considered that such a phenomenon occurs due to the following effects.

That is, when γ _AL ≧ γ _P is satisfied, the polymer resin 11 is easily wetted on the insulating films 7 and 10, and a dome-shaped liquid crystal droplet 13 is formed. To explain why,
In general, it is known that a liquid having a surface energy smaller than the surface energy of a solid gets wet as a condition for the liquid to get wet on the solid surface. Here, in the present embodiment, the surface tension of the polymer material (liquid) is replaced with the critical surface tension of the polymer resin (solid). Such handling is difficult due to the difficulty in measuring the surface tension of the polymer material (liquid), and even if the surface tension of the polymer material (liquid) is replaced by the critical surface tension of the polymer resin, This is because there is almost no difference between the surface tension of the liquid) and the critical surface tension of the polymer resin (solid), and it is considered that this does not affect the wettability of the polymer material (liquid). Therefore, the critical surface tension gamma _AL insulating film, the critical surface tension gamma _P of the polymeric resin, gamma _AL
When ≧ γ _P is satisfied, the polymer material (liquid) is easily wetted on the insulating film. As described above, when the polymer material (liquid) is easily wetted on the insulating film, in the polymerization process of the polymer dispersed liquid crystal material including the polymer material and the liquid crystal material, the liquid crystal droplets deposited near the interface of the insulating film become: The polymer covering the liquid crystal droplet is pressed in a direction in contact with the insulating film, and a dome-shaped liquid crystal droplet 13 is formed.

When the dome-shaped liquid crystal droplet 13 is thus formed, it is considered that the optical hysteresis is reduced by the following mechanism. That is, due to the formation of the dome-shaped liquid crystal droplet 13, the liquid crystal molecules in the liquid crystal droplet 13 receive a strong alignment regulating force from the substrate interface. This regulating force propagates not only to the liquid crystal droplets 13 but also to the liquid crystal droplets 12, and all the liquid crystal droplets 12,
13 assists in regulating the interface at the liquid crystal / polymer resin interface. As a result, when the electric field is turned off from the electric field on state, all the liquid crystal molecules in the liquid crystal droplets 12 and 13 including the vicinity of the liquid crystal / polymer resin interface smoothly transition to the original random arrangement state. Therefore, optical hysteresis can be reduced.

Specifically, an applied voltage-light transmittance characteristic with reduced optical hysteresis is obtained as shown by a curve VTa shown in FIG. However, in the present invention, the driving voltage is higher than that of the conventional example shown by the curve VTb in FIG. Therefore, when a liquid crystal display element that reduces optical hysteresis and does not excessively increase the driving voltage is desired, an insulating film may be appropriately selected within a range that satisfies the relationship of the above equation (1).

Next, the relationship between the liquid crystal contained in the liquid crystal / polymer composite layer 4 and the insulating film will be described. That is, since the liquid crystal / polymer composite layer 4 contains liquid crystal in addition to the polymer resin, it is necessary to consider the relationship between the liquid crystal and the insulating film. According to the experimental results of the present inventor, when the relationship of the above formula (1) is satisfied and the relationship of the following formula (2) is satisfied, the liquid crystal molecules in the liquid crystal droplet 13 as shown in FIG. Was oriented substantially parallel to the substrate.

(Equation 8) Here, γ _LC indicates the surface tension of the liquid crystal. Conversely, when the relationship of the above equation (1) is satisfied and the relationship of the following equation (3) is satisfied, the liquid crystal molecules in the liquid crystal droplet 13 are substantially perpendicular to the substrate as shown in FIG. Oriented.

(Equation 9) This is because, when the relationship of γ _LC <γ _AL is satisfied, the liquid crystal is easily wetted, and the liquid crystal molecules in the liquid crystal droplet 13 receive a large alignment regulating force from the insulating film, and therefore, are substantially aligned in parallel. It is thought to be. On the other hand, if the relationship of γ _LC > γ _AL is satisfied, the liquid crystal becomes difficult to wet,
It is considered that the alignment control force from the insulating film to the liquid crystal molecules in the inside becomes small, so that the liquid crystal molecules are aligned almost vertically.

When comparing the state shown in FIG. 3A with the state shown in FIG. 3B, the scattering performance is good in FIG. 3A, but the electric field response is poor. Conversely, in the case of FIG. 3A, the scattering performance is poor, but the electric field response is good. Therefore, γ _LC > γ _AL or γ _LC <γ _AL depending on whether the scattering performance or the electric field response is prioritized in consideration of the use environment of the liquid crystal display element.
What is necessary is just to select a liquid crystal material satisfying the above.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements and the like of the constituent elements described in this embodiment are not intended to limit the scope of the present invention only to them unless otherwise specified. , Are merely illustrative examples.

The liquid crystal display device according to the present example has the same configuration as that of the above embodiment, and was manufactured as follows.

(1) Preparation of Empty Cell A transparent electrode made of ITO (corresponding to the pixel electrode 6 and the counter electrode 9), and insulating films 7 and 10 formed on the transparent electrode
A glass substrate (corresponding to the array substrate 2 and the counter substrate 3) is prepared, and a sealing resin 15 also serving as a spacer is formed on the surface of the insulating film 7 of one of the glass substrates (for example, the array substrate 2). An acid anhydride-curable epoxy resin in which glass fibers having a diameter of 13 μm are dispersed is applied to the array substrate 2.
Of the four sides, only one side was left with an opening of 3 mm, and the other side was printed with a width of 2 mm. Next, the array substrate 2
Above, the opposing substrate 3 is placed in a state where the electrode surfaces are opposed to each other. In this state, pressure is applied, and the adhesive is cured by heating at 150 ° C. for 2 hours to form an empty cell. The insulating films 7, 10
Is obtained by applying a solution containing 3% by weight of a polyimide component and spinning it at 180 ° C. for 1 hour after spinner coating.
The insulating films 7 and 10 were made of a material having the relationship of the formula (1). The critical surface tension γ _P of the polymer resin was measured in advance by the following method.

That is, as a material for forming the polymer resin,
59 parts by weight of 2-ethylhexyl acrylate (manufactured by Nacalai Tesque, Inc.), 14 parts by weight of lauryl acrylate (manufactured by Kyoeisha Yushi Kagaku Kogyo KK), 1,6-hexanediol diacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.)
A mixed composition (referred to as composition A) comprising 25 parts by weight of trade name Biscoat # 230) and 2 parts by weight of Irgacure 651 (trade name, manufactured by Ciba Geigy Co., Ltd.) was prepared. The composition A was polymerized by ultraviolet irradiation at 25 ° C. under a nitrogen atmosphere to prepare a polymer film. A high-pressure mercury lamp was used for ultraviolet irradiation, and a light cut filter was arranged on the light irradiation surface to perform polymerization. As a light cut filter,
UV35 (trade name) manufactured by Toshiba Color Glass Co., Ltd. was used. The high-pressure mercury lamp used had a main wavelength of 365 nm and an ultraviolet intensity of 50 mW / cm ² , and was irradiated for 60 seconds. The critical surface tension γ _P of the polymer film thus produced was determined by the Zisman plot method. That is, a wettability test standard reagent (manufactured by Nacalai Tesque, Inc.) having various surface tensions was adhered to the polymer film surface, and the respective contact angles θ were measured. Next, the horizontal axis
The surface tension of various wettability test standard reagents was plotted on the sθ and the vertical axis to determine the surface tension at which cosθ = 1, and this surface tension was defined as the critical surface tension γ _P of the polymer film.
As a result, at 20 ° C., γ _P was 30.6 dyne / cm.

(2) Preparation of polymer-dispersed liquid crystal material The above composition A and the liquid crystal material were mixed with composition A: liquid crystal = 20: 80.
To prepare a polymer-dispersed liquid crystal material.

(3) Polymerization treatment The above polymer-dispersed liquid crystal material was injected by a vacuum injection method from the opening of the empty cell produced in the above (1), and the opening was sealed after the injection. Next, polymerization was performed at 25 ° C. using a high-pressure mercury lamp as a light source. At this time, polymerization was performed by disposing a light cut filter on the light irradiation surface. As a light cut filter, UV35 (trade name) manufactured by Toshiba Color Glass Co., Ltd. was used. The high-pressure mercury lamp has a main wavelength of 36.
Irradiation was performed for 60 seconds using a material having an ultraviolet intensity of 5 mW / cm ² at 5 nm. When the polymerization was completed, the liquid crystal display device shown in FIG. 1 was produced.

(Embodiments 1) to (Embodiment 4) In the embodiments 1 to 4, as the materials of the insulating films 7 and 10, four kinds of insulating film materials ( Product name: AL1051, AL5417, JALS21
2 (all manufactured by Nippon Synthetic Rubber Co., Ltd.) and SE7992 (Nissan Chemical Co., Ltd.). Also, as a liquid crystal material,
TL205 (trade name: manufactured by Merck Ltd., γ _LC = 29.5 dyne / cm) satisfying the relationship of the above formula (2) was selected. Using these various materials, various liquid crystal display elements were manufactured by the above manufacturing method. In these liquid crystal display elements, the alignment state of the liquid crystal molecules in the liquid crystal droplet 13 is shown in FIG.
As shown in (a), it was oriented perpendicular to the array substrate 2. Optical hysteresis of these liquid crystal display elements was measured under the following conditions. The results are shown in Table 1 below. Note that these liquid crystal display elements are referred to as liquid crystal display elements X1, X2, X3, and X4 of the present invention.

Experimental conditions (1) The critical surface tension γ _AL of each insulating film material was determined by the Disman plot method at 20 ° C. using a standard reagent for wettability test (manufactured by Nacalai Tesque, Inc.). Things.

(2) The value of the hysteresis was defined as follows. The applied voltage-light transmittance characteristic of the scattering state → transmission state and the applied voltage-light transmittance characteristic of the transmission state → scattered state are measured, and the transmittance changes by 50% in each applied voltage-light transmittance characteristic. When the voltage is V50 ↓ and V50 ↓ respectively
When a, the value H _v, which is defined by the following equation was used as an index of the optical hysteresis. _{H v = (V50 ↑ -V50 ↓} ) / V50 ↓ × 100 [%] Incidentally, in the present experiment, by measuring the voltage hysteresis, although performance evaluation of liquid crystal display device, which is the voltage It is based on the fact that the change in hysteresis is also related to the change in optical hysteresis. That is, if the voltage hysteresis is reduced, it can be determined that the optical hysteresis is also reduced, and it can be said that the deterioration of display quality due to the optical hysteresis can be prevented.

(3) The critical surface tension γ _P of the polymer resin is
30.6 dyne / c at 20 ° C. as in the above embodiment.
m.

(Comparative Examples 1) to (Comparative Example 3) The liquid crystal display elements according to Comparative Examples 1 to 3 each have three types of insulating film materials (trade names: JALS214, JA).
LS246 (all manufactured by Nippon Synthetic Rubber Co., Ltd.), SE12
11 (trade name: manufactured by Nissan Chemical Industries, Ltd.)), except that the above-mentioned production method was used. The three types of insulating film materials are insulating film materials that do not satisfy the relationship of the above equation (1). Further, the optical hysteresis of these liquid crystal display elements was measured under the above conditions. The results are shown in Table 1 below. Note that these liquid crystal display elements are referred to as comparative liquid crystal display elements Y1, Y2, and Y3.

[Table 1]

(Embodiment 5) The liquid crystal display device according to the present embodiment 5 has a liquid crystal material BL00 which satisfies the above equation (3).
Except for using No. 2 (trade name), it was produced by the above-described production method. The liquid crystal display element according to the present embodiment has
3B, the liquid crystal molecules were aligned in a direction perpendicular to the array substrate 2 as shown in FIG. This liquid crystal display element is referred to as a liquid crystal display element X5 of the invention.

Further, with respect to the liquid crystal display element X5 of the present invention,
The transmittance was measured by the following method. That is, using a liquid crystal display (LCD) 500 (manufactured by Otsuka Electronics Co., Ltd.) as a measuring device and arranging a green filter between a white light source and the liquid crystal display element, the liquid crystal display element is irradiated with green (G) light.
The transmittance when no voltage was applied was measured. Further, the surface tension γ _LC of the liquid crystal material (trade name: BL002) was measured by a drop weight method. The results are also shown in Table 2. Table 2 below also shows data on the liquid crystal display element X1 of the present invention.

[Table 2]

[Results] As is clear from Table 1 above,
Critical surface tension of matrix γ_PGreater critical surface tension
Force γ_ALLiquid crystal display element X of the present invention provided with an insulating film having
1, X2, X3 and X4 have very small hysteresis
Has become. On the other hand, the critical surface tension of the polymer matrix
γ_PSmaller critical surface tension γ_ALProviding an insulating film having
In the liquid crystal display elements Y1, Y2, and Y3, the hysteresis
Is big. Therefore, γ_AL> Γ _PInsulating film that satisfies the relationship
Has reduced hysteresis.
Is recognized.

As is clear from Table 2, the transmittance of the liquid crystal display device X1 of the present invention is lower than that of the liquid crystal display device X5 of the present invention. Therefore, although the scattering performance of the liquid crystal display device X5 of the present invention was slightly lower than that of the liquid crystal display device X1 of the present invention, the voltage hysteresis was 0.5% and the hysteresis was reduced. The response speed was as good as 37 ms.

[0042]

As described above, according to the present invention, on a pair of substrates sandwiching a liquid crystal polymer composite layer, the critical surface tension γ _P of the polymer resin and the critical surface tension satisfying the relationship of the following formula (1) are satisfied. Providing the insulating film having the surface tension γ _{A L} has an effect that a liquid crystal display element with improved hysteresis characteristics can be realized.

(Equation 10) (However, in the formula, γ _P indicates a critical surface tension of the polymer resin, and γ _AL indicates a critical surface tension of the insulating film.)

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display element according to an embodiment of the present invention.

FIG. 2 is a view showing an alignment state of a liquid crystal droplet 13;

FIG. 3 is a schematic diagram illustrating a display principle of a liquid crystal display device having a polymer dispersed liquid crystal layer.

FIG. 4 is a graph showing hysteresis characteristics of the present invention and a conventional example.

[Explanation of symbols]

 1: Liquid crystal display element 2: Array substrate 3: Counter substrate 4: Liquid crystal polymer composite layer 6: Pixel electrode 7, 10: Insulating film 9: Counter electrode 11: Polymer resin 12: Spherical liquid crystal droplet 13: Domed liquid crystal drop

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Kubota 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 2H089 HA04 JA04 KA08 QA16 RA04 SA17 TA05 2H090 HA03 HB13X HD01 KA11

Claims (3)

[Claims] 1. A method according to claim 1, further comprising the steps of:
In a liquid crystal display element having a structure in which a liquid crystal polymer composite layer containing a liquid crystal and a polymer resin is disposed, an insulating film is provided on the electrode, and the critical surface tension of the insulating film is γ _AL , A liquid crystal display device characterized in that, when the critical surface tension of the polymer matrix is γ _P , γ _AL and γ _P satisfy the following expression (1). (Equation 1) 2. When the surface tension of the liquid crystal is γ _LC ,
2. The liquid crystal display device according to claim 1, wherein the γ _AL and γ _LC satisfy the relationship of the following equation (2). (Equation 2) 3. When the surface tension of the liquid crystal is γ _LC ,
2. The liquid crystal display device according to claim 1, wherein said γ _AL and γ _LC satisfy the relationship of the following expression (3). (Equation 3)