JPH0895054A - Liquid crystal display element and manufacture thereof - Google Patents

Abstract

PURPOSE: To dispense with visual angle dependence so as to provide a wide angle of visibility by arranging areas having different phase separation structures each other in an oriented film made of non-compatible polymer alloy and varying orientation of liquid crystal in every area. CONSTITUTION: On an opposed face, on which a transparent electrode film 5 and an oriented film controlling thin film 6 are formed, of a glass substrate 2, a polymer alloy oriented film 7 is formed and covers the whole surface. The oriented film 7 is formed in such ways as mixing two kinds of polyimide RN 713 and RN 739 which are non-compatible with each other in n- methylpyrolidone so as to turn them into polymer alloy, applying the polymer alloy by a spin coating method, and burning it after evaporating a solvent. The oriented film 7 formed in this way has a phase separation structure on the basis of relation between surface free energy of the two kinds of polyimides constituting the polymer alloy and surface energy of its substrate phase. As a result, intensive visual angle dependence, which is observed when liquid crystal is oriented in one direction, is dispensed with, so that a wide angle of visibility can be obtained.

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 in which the alignment of liquid crystal is controlled by an alignment film formed on a substrate, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display element using nematic liquid crystal has been widely used as a segment display type for watches and calculators, and as a dot matrix display type for computers and word processors. Further, there are a simple matrix method and an active matrix method as a dot matrix display type driving method. In the active matrix method, a TFT ([Thin Film Transistor] thin film transistor) is provided on each pixel electrode.
By providing such a switching element as described above, gradation display and color display can be facilitated and a large screen can be displayed.

In the above active matrix system, the TN
[Twisted Nematic] type nematic liquid crystal is often used. In this TN method, the orientation direction of the nematic liquid crystal molecules is made orthogonal between the facing substrates, and the twist angle is 90.
This is a twist orientation. Further, in the simple matrix system, an STN [Super-Twisted Nematic] system nematic liquid crystal is often used. In this STN method, the twist angle of the nematic liquid crystal molecules is 180 ° to 36 °.
It is a super twist orientation of 0 °.

As a method of aligning the above nematic liquid crystal,
Various things have been proposed conventionally. For example, Japanese Patent Laid-Open No. 4-57028 proposes a method of rubbing an alignment film of polyimide, and Japanese Patent Laid-Open No. 5-323327.
In the publication, a method of rubbing an alignment film of a polymer alloy having a phase separation structure is proposed.

As a method of not performing the rubbing treatment, in JP-A-4-181922, a vapor deposition polymerization method of forming a polymer film by depositing a monomer on the surface of an electrode and then polymerizing the monomer, or an LB film is formed. LB method was proposed,
Japanese Unexamined Patent Publication (Kokai) No. 3-293324 proposes a method of forming an alignment film of a polymer alloy by the LB method and aligning liquid crystal molecules in one direction.

[0006]

However, all of the above-mentioned conventional methods for aligning nematic liquid crystals are for aligning liquid crystal molecules in one direction. Therefore, a liquid crystal display device in which liquid crystal is aligned by this method is used for display. When this is done, there is a problem that a strong viewing angle dependency occurs depending on the alignment direction, and the viewing angle is biased, so that a wide viewing angle cannot be obtained.

As a method of eliminating such a viewing angle dependency and obtaining a wide viewing angle, Japanese Patent Laid-Open No. 5-203951 discloses dividing a region within each picture element and performing rubbing processing in which the direction is different for each region. The method of applying is proposed,
Japanese Patent No. 4162 proposes a non-rubbing method in which the alignment film is not rubbed at all.

However, in the method of performing rubbing treatment in different directions, not only the number of rubbing treatment steps is increased, but also each region is protected by a resist film during the rubbing treatment, so that the resist film is peeled off. When this is done, the alignment film deteriorates and the alignment becomes disturbed, which causes a problem that a disclination line is generated and the display quality is degraded. Moreover, the pixel area is 2
When the rubbing process is performed in a direction orthogonal to each other by dividing, there is a viewing angle dependence of these vertical direction and horizontal direction,
It was still insufficient to obtain a uniform and wide viewing angle.

Also, in the non-rubbing method, the alignment of the liquid crystal becomes insufficient and the alignment is greatly disturbed, so that the disclination line is generated and the display quality is deteriorated.

The present invention solves the above-mentioned conventional problems, in which the liquid crystal is aligned without rubbing and the alignment is made different for each region of the alignment film to obtain a uniform wide viewing angle. Another object of the present invention is to provide a liquid crystal display device and a method for manufacturing the same.

[0011]

The liquid crystal display device of the present invention is a liquid crystal display device in which a pair of substrates each having an electrode film of a predetermined pattern formed thereon are opposed to each other with a liquid crystal interposed therebetween. A layer film of a polymer alloy in which phase separation has occurred on the surface of one or both of the substrates facing the liquid crystal, which is composed of regions of two kinds of phase separation structures different from each other, and which has one phase separation structure. An alignment film is formed in which a plurality of regions are arranged in substantially the same pattern and dispersed according to a certain degree of regularity, whereby the above object is achieved.

Further, the liquid crystal display element of the present invention is a liquid crystal display element in which a pair of substrates each having an electrode film of a predetermined pattern formed thereon face each other with a liquid crystal sandwiched therebetween. Is a layer film of a polymer alloy having phase separation on the opposite surface in contact with the two, and is composed of two different types of phase separation structure regions, and one of the phase separation structure regions has substantially the same pattern to some extent. An alignment film, which is arranged in a large number dispersed by regularity, is formed, and phase separation having the same composition or a different composition as the polymer alloy of the one substrate is formed on the opposite surface of the other substrate in contact with the liquid crystal. A layered film of a polymer alloy that has been created,
It is composed of two different types of phase separation structure regions, and one of the phase separation structure regions is arranged in substantially the same pattern and regularity as the one phase separation structure region of the alignment film of the one substrate. The alignment film is formed to achieve the above object.

Further, preferably, in the liquid crystal display device of the present invention, the electrode films of the pair of substrates are arranged substantially regularly in the pixel regions facing each other in substantially the same pattern, and the phase separation structure of one of the alignment films is formed. Areas are arranged in substantially the same pattern for each of the picture element areas.

Further, preferably, in all of the picture element regions in which the electrode films of the pair of substrates in the liquid crystal display element of the present invention face each other, one of the phase separation structure regions of the alignment film is present in each picture element region. At least one place is arranged in each.

Further, in the method for manufacturing a liquid crystal display device of the present invention, an alignment film is formed on the facing surfaces of a pair of substrates, each having a predetermined pattern of electrode films formed thereon, and the liquid crystal is sandwiched between the pair of substrates. In the method of manufacturing a liquid crystal display device, wherein the facing surfaces of the substrates are arranged to face each other, a plurality of regions having substantially the same pattern and arranged with a certain degree of regularity on the facing faces of the one or both substrates or the regions. A thin film patterned in a region other than the area on the opposite surface of the substrate on which the alignment film controlling thin film is formed after forming an alignment film controlling thin film having a different interface free energy from the facing surface of the substrate. To form an alignment film of an incompatible polymer alloy, thereby achieving the above object.

Further, preferably, in the method for producing a liquid crystal display element of the present invention, a pair of substrates are arranged face to face with a liquid crystal sandwiched therebetween, and then the liquid crystals are heated until they are in an isotropic state, and then to room temperature. Cooling.

[0017]

A large number of electrode films are formed in a line shape in a direction orthogonal to each other on both of a pair of substrates as in the case of a simple matrix type liquid crystal display element, and one substrate is formed in a segment shape. The other substrate may be formed in a common shape over the entire surface. In the case of an active matrix type liquid crystal display element, a large number of this electrode film is formed in a matrix on one substrate and connected to a source line or the like via a switching element. In this case, an electrode film is usually formed on the entire surface of the other substrate in a common shape.

A liquid crystal material such as a nematic liquid crystal is used as the liquid crystal. A chiral dopant (optically active substance) may be added to the nematic liquid crystal to control the helical pitch. Further, a guest-host type liquid crystal display device capable of displaying a halftone can be obtained by adding a dichroic dye to the nematic liquid crystal.

The polymer alloy is a polymer multi-component system (mult
icomponent polymer), which is a mixture of two or more types of polymers. And, those in which mixed heterogeneous polymers are covalently bonded to each other are classified as a block alloy or a graft alloy,
Those in which different kinds of polymers are not covalently bonded are classified as blended alloys. The polymer to be mixed is
It may be a random copolymer in which different monomers are randomly polymerized or an alternating copolymer in which different monomers are alternately polymerized. However, these random copolymers and alternating copolymers themselves are not included in the polymer alloy because the interaction between different monomers is dominant.

The above polymer alloy can cause phase separation by mixing different polymers which are incompatible with each other. The incompatibility means a property in which different polymers are not mixed uniformly and are mixed in a non-uniform state, and the incompatibility is exhibited depending on the combination of the different polymers and the proportion of the mixture. This incompatible polymer alloy has a phase separation structure in which thermodynamically the most stable equilibrium state is obtained according to the relationship between the interfacial free energy of each different polymer and the interfacial free energy of the facing surface of the substrate.

However, if it is simply formed on the facing surface of the substrate, the phase separation structure becomes uniform over the entire facing surface. Therefore, for example, as described in claim 5, if an incompatible polymer alloy alignment film is formed after forming an alignment film control thin film having a different interface free energy from the facing surface of the substrate in a predetermined pattern. , Different from each other 2
It is possible to form an alignment film including regions of different types of phase-separated structures. This thin film for controlling an orientation film is made of materials having different interfacial free energies with respect to at least one component polymer of the polymer alloy, which is first applied to the entire opposing surface and then patterned to form an arbitrary pattern. By forming an alignment film of an incompatible polymer alloy on this, regions of two types of phase separation structures can be formed according to the pattern of the alignment film controlling thin film, whereby one phase separation can be achieved. A large number of structural regions can be arranged in the same pattern with some regularity. A resist film or the like can be used as a material of the alignment film controlling thin film used here.

As a method of providing such two kinds of phase-separated structures, in addition to using the above alignment film controlling thin film, rubbing treatment, chemical treatment such as glow discharge or etching, or electromagnetic wave is used. It is also possible to use a method in which a part of the facing surface of the substrate is modified so as to have regions having different interface free energies by irradiating with radiation, ultraviolet rays, or excimer laser. At this time, by patterning a photosensitive resist film or other film to mask a part of the facing surface of the substrate and protecting this masked region from these treatments, the interfacial free energy can be increased in any pattern. Different regions can be formed. Thus, a large number of regions having one phase separation structure can be arranged in the same pattern with some regularity.

The liquid crystal filled on the alignment film has a surface structure based on the phase separation structure of the alignment film, a π-electron interaction, a wettability (adhesiveness), etc. without rubbing the alignment film. Accordingly, they are regularly oriented. When the liquid crystal is aligned on the alignment film having the phase separation structure in this way, the pretilt angle can be increased and the characteristics of the TN or STN nematic liquid crystal can be improved. Moreover, since the phase separation structure of the alignment film is different in each region, the alignment of the liquid crystal is also different in each region. In addition, depending on the phase separation structure, the liquid crystal can be aligned radially in the normal direction of the boundary of the region or concentrically such as concentric circles along the boundary. However, since the flow alignment of the liquid crystal may occur at the time of injecting the liquid crystal, in such a case, the liquid crystal is heated to once in an isotropic state and then cooled to room temperature as described in claim 6. This ensures that the above-mentioned orientation is performed.

Therefore, according to the present invention, the orientation of the liquid crystal can be made different in each region where the phase separation structure of the orientation film is different, so that the strong viewing angle dependence as in the case where the liquid crystal is oriented in one direction. And a wide viewing angle can be obtained. Further, when the liquid crystal in any of the regions is radially or concentrically aligned, the viewing angle characteristic becomes axially symmetric, so that a more uniform and wide viewing angle can be obtained. Moreover, on each region of the alignment film, the liquid crystal is regularly aligned due to its uniform phase-separated structure to form an alignment unit, so that the display quality is deteriorated by the disclination line or the like that occurs when the alignment is non-uniform. There is no such thing.

Furthermore, according to the present invention, since the phase separation structure of each region on the alignment film and the arrangement of these regions can be arbitrarily determined, liquid crystal alignment units of various structures can be formed. In addition, it is possible to create a structure of a special alignment unit of liquid crystal that cannot be formed by an alignment film having a uniform phase separation structure.

The alignment film composed of the regions of the above-mentioned two types of phase-separated structures can be provided not only on one of the pair of substrates but also on both substrates. In this case, as described in claim 2, it is convenient to control each alignment unit of the liquid crystal by matching the pattern of each region of the alignment films formed on both substrates. The pattern of each region of such an alignment film is
It can be arbitrarily controlled by patterning the above-mentioned alignment film controlling thin film.

Here, when the regions of the same pattern of both alignment films are arranged to face each other and the regions of both alignment films facing each other have the same phase separation structure, The orientation of the liquid crystal can be matched on both substrates. Further, when the phase separation structure between the regions facing each other of both alignment films is reversed between the other regions or when they are completely different from each other, both of the alignment units of the liquid crystal Different orientations can be performed on the substrate side. Therefore, by appropriately determining these phase separation structures, the alignment of the liquid crystal can be controlled arbitrarily for each alignment unit, and various axial symmetry can be imparted and the twist angle can be changed to adjust the brightness. It is also possible to do such things. Further, by adding a chiral dopant to the liquid crystal, for example, each alignment unit can be made to have a radial and concentric alignment on both substrate sides, and such a configuration of the alignment unit makes the display particularly bright. Suitable if you need to. Further, when the regions of the same pattern of both alignment films are arranged so as not to face each other and displaced from each other, the alignment unit of the liquid crystal is narrower than the region where the phase separation structure on one alignment film is the same. Can be divided, and more versatile control becomes possible.

As for each area of the alignment film, one area can be made to substantially coincide with the picture element area. In this case, since a liquid crystal alignment unit is formed for each pixel region, for example, only liquid crystal molecules of the alignment unit of this pixel region are aligned parallel to the substrate surface when no voltage is applied, and liquid crystal molecules of other regions are aligned. It is possible to easily create a structure in which the molecules are oriented perpendicularly to the substrate surface, and it is possible to improve light utilization efficiency and display quality.

However, when the alignment units in the picture element region of the liquid crystal are oriented in axial symmetry, a quenching pattern is generated, and the quenching pattern becomes conspicuous due to the conditions such as the pixel size, which may deteriorate the display quality. . Therefore, in such a case, as described in claim 4, by disposing two or more regions having a phase separation structure in each pixel region, a plurality of liquid crystal alignment units are provided for each pixel. The extinction pattern can be made inconspicuous by being positioned. Also, this is
The display quality is also averaged when the phase separation structures of the regions of the same pattern facing each other in both alignment films are reversed or different, or when the regions of the same pattern facing each other are displaced.

[0030]

Embodiments of the present invention will be described below.

1 to 5 show a first embodiment of the present invention. FIG. 1 is a vertical sectional view schematically showing the structure of a liquid crystal display device, and FIG. 2 is a thin film for controlling an alignment film. FIG. 3 is a partial plan view showing a formation pattern, FIG. 3 is a partial plan view showing regions of the alignment film having different phase separation structures, FIG. 4 is a graph showing viewing angle characteristics of the liquid crystal display element 1, and FIG. 5 is a viewing angle of the liquid crystal display element 1. It is a radar chart which shows a characteristic.

In this embodiment, a simple matrix type liquid crystal display device will be described. This liquid crystal display element 1 is shown in FIG.
As shown in FIG. 3, a pair of glass substrates 2 and 3 are arranged to face each other with a liquid crystal 4 interposed therebetween. On the opposite surface of the one glass substrate 2 shown in the lower part of the drawing, which is in contact with the liquid crystal 4,
A large number of transparent electrode films 5 made of ITO ([Indium Tin Oxide]) are formed in the form of strips at regular intervals from the front side to the back side in the figure (however, in the figure, two are formed for simplicity). Only the transparent electrode film 5 of FIG.

An alignment film controlling thin film 6 is formed on the transparent electrode film 5 in a predetermined pattern. The pattern of the alignment film controlling thin film 6 covers the transparent electrode film 5 and, as shown in FIG. 2, a circular region of the same size is regularly punched to expose the surface of the transparent electrode film 5. It was done like this. The orientation film controlling thin film 6 is made of a thin film material having an interface free energy different from that of the facing surface of the glass substrate 2, and here, a negative resist of OMR83 (manufactured by Tokyo Ohka Co., Ltd.) is used. Then, this resist is applied on the entire surface of the glass substrate 2 opposite to the glass substrate 2 by spin coating, dried, covered with a photomask, exposed to light, and the unexposed portion is removed. To form.

On the facing surface of the glass substrate 2 on which the transparent electrode film 5 and the alignment film controlling thin film 6 are formed, a polymer alloy alignment film 7 is formed so as to cover the entire surface. This alignment film 7 is a polymer alloy prepared by mixing RN713 and RN739 (manufactured by Nissan Chemical Industries, Ltd.), which are two types of polyimides that are incompatible with each other, in n-methylpyrrolidone, and after applying the polymer alloy by spin coating, the solvent It is formed by evaporating and firing. The alignment film 7 thus formed is in a thermodynamically most stable equilibrium state according to the relationship between the interfacial free energy of the two types of polyimide forming the polymer alloy and the interfacial free energy of the underlying layer. Take structure. Therefore, the region 7a on the alignment film controlling thin film 6, the transparent electrode film 5 and the glass substrate 2 are
Since the interfacial free energy is different between the exposed area 7b and the exposed area 7b, different phase separation structures are formed. That is, when observing the case of the present embodiment with a polarization microscope, as shown in FIG. 3, in the region 7a on the alignment film controlling thin film 6, the phase separation of the sea-island structure is achieved.
In the circular region 7b where the transparent electrode film 5 was exposed, a radial phase separation morphology was confirmed. In addition, the alignment film 7 includes
No rubbing treatment was applied.

As the polymer alloy, in addition to the combination of polyimides (PI) used in this example, polyamide (PA) and PI, polyethylene terephthalate (PET) and polybutylene terephthalate (PBT),
PS alloys such as nylon and general-purpose olefin polymers (PO), POs, POs and polystyrenes (PS), PAs and elastomers, polyvinyl chloride (PVC) alloys, PO alloys, polymethylmethacrylate (PMMA) alloy, PA alloy, polyacetal (POM) alloy, polycarbonate (PC)
Alloy, polyphenylene ether (PPE) alloy, PET alloy, polyphenylene sulfide (PP
S) alloy, polyarylene ether ketone (PAE
Various materials such as K) type alloys, amorphous polyarylate (PAr) type alloys and PI type alloys can be used.

On the opposite surface of the other glass substrate 3 shown in FIG. 1 in contact with the liquid crystal 4, a large number of transparent electrode films 8 made of ITO are formed in strips at equal intervals in the left-right direction in the drawing. (However, only one transparent electrode film 8 is visible in the figure). Therefore, the transparent electrode film 5 on the one glass substrate 2 is orthogonal to each other, and a region where these transparent electrode films 5 and 8 face each other becomes a pixel region. An alignment film 9 having no ordinary phase separation structure is formed on the transparent electrode film 8 so as to cover the entire surface. The alignment film 9 was not rubbed.

In the liquid crystal display element 1, the pair of glass substrates 2 and 3 are bonded at a predetermined interval so that the surfaces facing each other face each other, and the liquid crystal 4 is filled in these spaces and the end portion is sealed with the sealing resin 10. It is composed by sealing. At this time, the gap between the glass substrates 2 and 3 is about 5.5 μm. The liquid crystal 4 is a nematic liquid crystal having a refractive index anisotropy Δn of 0.081 and a chiral dopant added so that the twist angle is 90 °. Then, in order to prevent the flow orientation at the time of injecting the liquid crystal 4, the liquid crystal 4 is heated to an isotropic state and then cooled to room temperature by air cooling.

The liquid crystal display device 1 having the above-described structure has polarizing plates 11 and
Complete by placing 12. Also, the drive circuit 1
Display is driven by connecting the output of 3 to each of the transparent electrode films 5 and 8.

When the liquid crystal display element 1 constructed as described above is observed with a polarization microscope, the liquid crystal 4 constitutes an alignment unit in each of the regions 7a and 7b of the alignment film 7, and each alignment unit forms liquid crystal molecules. A regular alignment was confirmed. Further, when the liquid crystal display element 1 was actually driven for display and the viewing angle characteristics were evaluated, as shown in FIG.
A sufficient change in the transmittance was observed even at an angle of °, and it was confirmed that the electro-optical characteristics were excellent, and an iso-contrast curve A with a contrast of 10 as shown in FIG. On the other hand, it was confirmed to have a wide viewing angle with a contrast of 10 or more in the range of ± 65 ° or more.

Further, when the chiral dopant is not added to the liquid crystal 4 or when the display brightness is adjusted by changing the addition amount of the chiral dopant, the display quality does not deteriorate, and the dichroic dye is used. It was confirmed that the liquid crystal display device of the present invention has excellent display quality for clearly displaying a halftone even when used as a reflection type liquid crystal display device.

Further, instead of forming the orientation film controlling thin film 6, a part of the surface of the transparent electrode film 5 was roughened by etching in the same pattern as the orientation film controlling thin film 6 for surface modification. Also in this case, the same regions 7a and 7b different from each other in the phase separation structure as described above were formed in the alignment film 7, and the result that the viewing angle characteristics and the display quality were similarly improved was obtained.

FIG. 20 shows a comparative example for comparison with the present invention and is a vertical sectional view schematically showing the structure of a liquid crystal display device. The constituent members having the same functions as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In the liquid crystal display element 1 of this comparative example, after the transparent electrode film 5 is formed on the facing surface of the one glass substrate 2, instead of the alignment film 7, an ordinary phase is formed so as to cover these surfaces. An alignment film 14 having no separation structure is formed. Therefore, the alignment film controlling thin film 6 is formed on the transparent electrode film 5.
Is not formed. However, other configurations are the same as those of the liquid crystal display element 1 shown in FIG. Note that the alignment film 14 was not rubbed.

When the liquid crystal display element 1 of the present comparative example thus constructed was observed with a polarization microscope, a disclination line was observed in both cases of no voltage application and no voltage application. It was confirmed that the liquid crystal 4 in the applied state was randomly twisted by 90 °. It was also confirmed by visual evaluation that display unevenness and display roughness were conspicuous and the display quality was low. Further, when the viewing angle characteristics of the conventional TN are compared, as shown in FIG. 5, the conventional TN has an isocontrast curve B having a very high viewing angle dependency, as compared with the isocontrast curve A in the first embodiment. is there.

6 and 7 show a second embodiment of the present invention. FIG. 6 is a vertical sectional view schematically showing the structure of a liquid crystal display element, and FIG. 7 shows the alignment state of liquid crystals. It is a partial top view. The constituent members having the same functions as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In the liquid crystal display element 1 of this embodiment, the alignment film controlling thin film 15 and the alignment film 1 are formed on the other glass substrate 3 as well as the alignment film controlling thin film 6 and the alignment film 7 on the one glass substrate 2.
The case where 6 is formed will be described. The alignment film control thin film 15 is formed on the transparent electrode film 8 of the glass substrate 3 with the same material as the alignment film control thin film 6 in the same pattern and the same positional relationship. Further, on the facing surface of the glass substrate 2 on which the alignment film controlling thin film 6 is formed, an alignment film 16 made of an incompatible polymer alloy of the same material as the alignment film 7 is formed. Therefore, regions 16a and 16b having different phase separation structures are also formed in the alignment film 16. Also,
The phase separation structure of these regions 16a and 16b is the same as the phase separation structure of the regions 7a and 7b in the alignment film 7, respectively. The other structure is the same as that of the liquid crystal display element 1 of the first embodiment.

When observed with a polarization microscope before the pair of glass substrates 2 and 3 are bonded to each other, both alignment films 7 and 16 are observed.
In the regions 7a and 7b and the regions 16a and 16b, the same sea-island structure and radial morphology of phase separation as in the first embodiment were confirmed. Further, when observing the completed liquid crystal display element 1 with a polarization microscope, the liquid crystal 4 constitutes an alignment unit in each of the regions 7a and 16a and between the regions 7b and 16b, and liquid crystal molecules are formed in each alignment unit. The orientation was regularly aligned, and a quenching pattern as shown in FIG. 7 was observed.

The alignment film 16 is made of an incompatible polymer alloy made of a material different from that of the alignment film 7, and the phase separation structure of the regions 16a and 16b of the alignment film 16 is also the region 7 of the alignment film 7.
You may make it completely different from a and 7b.

In this case, the alignment film 16 on the glass substrate 3 is formed.
Was observed with a polarization microscope, a phase separation structure different from that of the alignment film 7 of the glass substrate 2 was confirmed. Further, when the completed liquid crystal display element 1 was observed with a polarization microscope, the alignment film 16
Axisymmetric alignment of the liquid crystal 4 different from that of the same material was observed.

It was confirmed that the liquid crystal display element 1 having the above-described structure has a wide viewing angle and excellent display quality, like the liquid crystal display element 1 of the first embodiment. Similar results were obtained with addition of a chiral dopant and addition of a dichroic dye, and the same was obtained when surface modification was performed in place of the alignment film controlling thin film 15.

8 to 10 show a third embodiment of the present invention. FIG. 8 is a vertical sectional view schematically showing the structure of a liquid crystal display element, and FIG. 9 shows an alignment film controlling thin film. FIG. 10 is a partial plan view showing a formation pattern, and FIG. 10 is a partial plan view showing regions of the alignment film having different phase separation structures. The constituent members having the same functions as those of the second embodiment shown in FIG. 6 are designated by the same reference numerals and the description thereof will be omitted.

In the liquid crystal display element 1 of this embodiment, the alignment film controlling thin films 6 and 15 and the alignment films 7 and 16 are formed in the same positional relationship on both glass substrates 2 and 3 as in the second embodiment. The case will be described. However, the pattern of the alignment film controlling thin film 6 is a checkered pattern as shown in FIG. 9, and the pattern of the alignment film controlling thin film 15 is the reverse thereof. Further, the alignment films 7 and 16 are both made of an incompatible polymer alloy made of the same material. Therefore, the region 7a of the alignment film 7 and the region 16a of the alignment film 16 facing each other have different phase separation structures, and the regions 7b and 16 are separated from each other.
a also has a different phase separation structure.

Observing with a polarizing microscope before bonding the pair of glass substrates 2 and 3 together, as shown in FIG.
The morphology of the sea-island structure phase separation was confirmed in the regions 7a and 16b of the alignment films 7 and 16, and the radial phase separation morphology was confirmed in the regions 7b and 16a. When the completed liquid crystal display element 1 is observed with a polarization microscope, the alignment units of the liquid crystal 4 are regularly aligned and axially symmetric alignment is observed, and the adjacent alignment units are vertically inverted from each other. It was confirmed that

It was confirmed that the liquid crystal display element 1 having the above-described structure has a wide viewing angle and excellent display quality, like the liquid crystal display elements 1 of the first and second embodiments. Similar results were obtained with addition of a chiral dopant and addition of a dichroic dye, and the same was obtained when surface modification was performed in place of the alignment film controlling thin film 15.

FIG. 11 shows a fourth embodiment of the present invention and is a vertical sectional view schematically showing the structure of a liquid crystal display element. The constituent members having the same functions as those of the third embodiment shown in FIG. 8 are designated by the same reference numerals and the description thereof will be omitted.

In the liquid crystal display element 1 of this embodiment, the alignment film controlling thin films 6 and 15 and the alignment films 7 and 16 are formed on both glass substrates 2 and 3 as in the second and third embodiments. The case will be described. Also, the alignment film controlling thin films 6, 15
Has the same pattern shown in FIG. 2 as the first and second embodiments. However, these patterns are substantially evenly displaced from each other so that only some of the same patterns face each other.

The alignment films 7 and 16 both use an incompatible polymer alloy made of the same material. Therefore, the region 7a of the alignment film 7 faces both the region 16a of the same phase separation structure and the region 16b of the different phase separation structure of the alignment film 16, and the region 7b of the alignment film 7 also has the same phase separation structure of the alignment film 16. The region 16b and the region 16a having a different phase separation structure face each other.

When observed with a polarization microscope before the pair of glass substrates 2 and 3 are bonded to each other, both alignment films 7 and 16 are observed.
In the regions 7a and 7b and the regions 16a and 16b, the same sea-island structure and radial morphology of phase separation as in the first embodiment were confirmed. Further, when the completed liquid crystal display element 1 is observed with a polarization microscope, it can be confirmed that the alignment units of the liquid crystal 4 exhibiting axially symmetrical alignment are formed in a narrower range than the regions 7a and 7b of the alignment film 7. It was It was also confirmed that the twist angle was different in each orientation unit.

The alignment film 16 is made of an immiscible polymer alloy made of a material different from that of the alignment film 7. The phase separation structure of the regions 16a and 16b of the alignment film 16 is also the region 7 of the alignment film 7.
You may make it completely different from a and 7b.

In this case, the alignment film 16 on the glass substrate 3 is formed.
Was observed with a polarization microscope, a phase separation structure different from that of the alignment film 7 of the glass substrate 2 was confirmed. Further, when the completed liquid crystal display element 1 was observed with a polarization microscope, the alignment film 16
Axisymmetric alignment of the liquid crystal 4 different from that of the same material was observed.

It was confirmed that the liquid crystal display element 1 having the above-described structure has a wide viewing angle and excellent display quality, like the liquid crystal display element 1 of the first embodiment. Similar results were obtained with addition of a chiral dopant and addition of a dichroic dye, and the same was obtained when surface modification was performed in place of the alignment film controlling thin film 15.

12 to 15 show a fifth embodiment of the present invention. FIG. 12 is a vertical sectional view schematically showing the structure of a liquid crystal display element, and FIG. 13 shows an alignment film controlling thin film. FIG. 14 is a partial plan view showing a formation pattern, FIG. 14 is a partial plan view showing regions of the alignment film having different phase separation structures, and FIG. 15 is a partial plan view showing an alignment state of liquid crystals. The constituent members having the same functions as those of the fourth embodiment shown in FIG. 11 are designated by the same reference numerals and the description thereof will be omitted.

In the liquid crystal display element 1 of the present embodiment, the alignment film controlling thin films 6 and 15 and the alignment films 7 and 16 are the same on both glass substrates 2 and 3 as in the second and third embodiments. The case of forming a positional relationship will be described. However, the patterns of the alignment film controlling thin films 6 and 15 are in the shape of a grid as shown in FIG. 13, and the rectangular transparent electrode films 5 and 8 below the alignment film controlling thin films 6 and 15 are exposed in a square pattern. The regions are arranged so that the transparent electrode films 5 and 8 on the glass substrates 2 and 3 have the same pattern and the same positional relationship as the picture element regions facing each other. Further, the alignment films 7 and 16 are both made of an incompatible polymer alloy made of the same material. Therefore, the region 7a of the alignment film 7 and the alignment film 1 facing each other
The region 16a of 6 has the same phase separation structure, and the regions 7b and 16a also have the same phase separation structure.

When observed with a polarization microscope before the pair of glass substrates 2 and 3 are bonded together, as shown in FIG.
The regions 7a and 16a of both alignment films 7 and 16 have a sea-island structure of phase separation, whereas the rectangular regions 7b and 1a have a sea-island structure.
In 6b, the morphology of radial phase separation was confirmed. Also,
When observing the completed liquid crystal display element 1 with a polarization microscope, alignment units of the liquid crystal 4 are formed in each pixel region, and liquid crystal molecules show regular alignment in each alignment unit, and the extinction as shown in FIG. A pattern was observed.

The alignment film 16 is made of an immiscible polymer alloy made of a material different from that of the alignment film 7, and the phase separation structure of the regions 16a and 16b of the alignment film 16 is also the region 7 of the alignment film 7.
You may make it completely different from a and 7b.

In this case, the alignment film 16 on the glass substrate 3 is formed.
Was observed with a polarization microscope, a phase separation structure different from that of the alignment film 7 of the glass substrate 2 was confirmed. Further, when the completed liquid crystal display element 1 was observed with a polarization microscope, the alignment film 16
Axisymmetric alignment of the liquid crystal 4 different from that of the same material was observed.

It was confirmed that the liquid crystal display element 1 having the above-described structure has a wide viewing angle and excellent display quality, like the liquid crystal display element 1 of the first embodiment. Similar results were obtained with addition of a chiral dopant and addition of a dichroic dye, and the same was obtained when surface modification was performed in place of the alignment film controlling thin film 15.

16 to 19 show a sixth embodiment of the present invention. FIG. 16 is a vertical sectional view schematically showing the structure of a liquid crystal display element, and FIG. 17 is a part of a pixel electrode substrate. FIG. 18 is a partial plan view showing a formation pattern of an alignment film controlling thin film, and FIG. 19 is a partial plan view showing an alignment state of liquid crystals.

In this embodiment, an active matrix type liquid crystal display device 20 will be described. As shown in FIG. 16, the liquid crystal display element 20 includes a pixel electrode substrate 22 and a common electrode substrate 23 that face each other with the liquid crystal 21 in between. A source bus line 24 and a gate bus line 25 shown in FIG. 17 are formed on the pixel electrode substrate 22.
A picture element electrode 26 is formed in a picture element region surrounded by these bus lines 24 and 25, and these bus lines 2
At the intersection of 4, 25, the switching transistor T
The FT 27 is formed. The TFT 27 is a thin film transistor formed on a glass substrate by using amorphous silicon or polysilicon. A black mask 28 and a color filter 29 are formed on the common electrode substrate 23, and a counter electrode 30 is formed on the entire upper surface of these layers.

The picture element electrode substrate 22 and the common electrode substrate 23
18 and the pixel electrodes 2 as shown in FIG.
An alignment film control thin film 31 in which the same pattern as 6 is formed in the same positional relationship is formed, and an alignment film 32 is formed on each of the alignment film control thin films 31. These alignment film control thin films 3
1 and the alignment film 32 are the same as the alignment film controlling thin films 6 and 15 and the alignment films 7 and 16 of the fifth embodiment.

Also in the liquid crystal display element 20 having the above structure,
An alignment unit of the liquid crystal 21 was formed for each pixel region on the pixel electrode 26, and the alignment of liquid crystal molecules as shown in FIG. 19 was observed. It was also confirmed that this liquid crystal display element 20 has a wide viewing angle and excellent display quality, like the liquid crystal display element 1 of the fifth embodiment.

[0072]

As described above, according to the liquid crystal display element of the present invention and the method for manufacturing the same, the regions of the phase separation structure different from each other are provided in the alignment film of the incompatible polymer alloy, and the liquid crystal is provided in each region. Since the orientations can be made different, it becomes possible to obtain a wide viewing angle by eliminating the strong viewing angle dependency as in the case where the liquid crystal is oriented in one direction. Further, since the phase separation structure of each region on the alignment film and the arrangement of this region can be arbitrarily determined to form alignment units of liquid crystal exhibiting various alignments, by selecting an appropriate structure, It is possible to further improve the display quality. Moreover, on each region of the alignment film, the liquid crystal is regularly aligned due to the uniform phase-separated structure, so that the display quality is not deteriorated by the disclination line or the like generated when the alignment is not uniform. .

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view schematically showing a structure of a liquid crystal display element, showing a first embodiment of the present invention.

FIG. 2 is a partial plan view showing a first embodiment of the present invention and showing a formation pattern of an alignment film controlling thin film.

FIG. 3 shows a first embodiment of the present invention and is a partial plan view showing regions of the alignment film having different phase separation structures from each other.

FIG. 4 is a graph showing a viewing angle characteristic of the liquid crystal display element 1, showing the first embodiment of the present invention.

FIG. 5 is a radar chart showing a viewing angle characteristic of the liquid crystal display element 1 according to the first embodiment of the present invention.

FIG. 6 shows a second embodiment of the present invention and is a vertical cross-sectional view schematically showing the structure of a liquid crystal display element.

FIG. 7 shows a second embodiment of the present invention and is a partial plan view showing an alignment state of liquid crystals.

FIG. 8 shows a third embodiment of the present invention and is a vertical sectional view schematically showing the structure of a liquid crystal display element.

FIG. 9 shows a third embodiment of the present invention and is a partial plan view showing a formation pattern of an alignment film controlling thin film.

FIG. 10 shows a third embodiment of the present invention and is a partial plan view showing regions of the alignment film having different phase separation structures from each other.

FIG. 11 is a longitudinal sectional view schematically showing the structure of a liquid crystal display element, showing a fourth embodiment of the present invention.

FIG. 12 shows a fifth embodiment of the present invention and is a vertical cross-sectional view schematically showing the structure of a liquid crystal display element.

FIG. 13 is a partial plan view showing the formation pattern of the alignment film controlling thin film according to the fifth embodiment of the present invention.

FIG. 14 shows a fifth embodiment of the present invention and is a partial plan view showing regions of the alignment film having different phase separation structures from each other.

FIG. 15 shows a fifth embodiment of the present invention and is a partial plan view showing an alignment state of liquid crystals.

FIG. 16 is a longitudinal sectional view schematically showing the structure of a liquid crystal display element, showing a sixth embodiment of the present invention.

FIG. 17 is a partial plan view of the pixel electrode substrate, showing the sixth embodiment of the present invention.

FIG. 18 shows a sixth embodiment of the present invention, and FIG. 18 is a partial plan view showing a formation pattern of an alignment film controlling thin film.

FIG. 19 is a partial plan view showing the alignment state of the liquid crystal according to the sixth embodiment of the present invention.

FIG. 20 is a vertical cross-sectional view schematically showing a structure of a liquid crystal display element, showing a comparative example for comparison with the present invention.

[Explanation of symbols]

 1, 20 Liquid crystal display element 2, 3 Glass substrate 4, 21 Liquid crystal 5, 8 Transparent electrode film 6, 15, 31 Alignment film control thin film 7, 16, 32 Alignment film 22 Picture element electrode board 23 Common electrode board 26 Picture element Electrode 30 Counter electrode

Claims (6)

[Claims] 1. A liquid crystal display device in which a pair of substrates, each having an electrode film of a predetermined pattern formed thereon, are arranged to face each other with a liquid crystal sandwiched therebetween. A layer film of a polymer alloy having phase separation, which is composed of two types of regions having a phase separation structure, and one of the regions having a phase separation structure has substantially the same pattern and has a large number of layers due to a certain degree of regularity. A liquid crystal display element having an alignment film which is dispersedly arranged. 2. In a liquid crystal display element, wherein a pair of substrates each having an electrode film of a predetermined pattern formed thereon are arranged to face each other with a liquid crystal sandwiched therebetween. A layered film of a polymer alloy that has been separated, and is composed of two types of regions having different phase separation structures, and one region of the phase separation structure has substantially the same pattern and is dispersed in large numbers according to a certain degree of regularity. Is formed on the opposite surface of the other substrate, which is in contact with the liquid crystal, with a layer film of a polymer alloy having the same composition as the polymer alloy of the other substrate or having a different composition. And a pattern having two different types of phase separation structure regions, and one of the phase separation structure regions has substantially the same pattern as one of the phase separation structure regions of the alignment film of the one substrate. The liquid crystal display device alignment layer disposed on the same regularity and is formed. 3. The picture element regions in which the electrode films of the pair of substrates face each other are arranged substantially regularly in substantially the same pattern, and one region of the phase separation structure of the alignment film is provided for each picture element region. The liquid crystal display element according to claim 1 or 2, wherein the liquid crystal display elements are arranged in substantially the same pattern. 4. With respect to all of the picture element regions in which the electrode films of the pair of substrates face each other, at least two regions of one phase separation structure of the alignment film are provided in each of the picture element regions.
The liquid crystal display element according to claim 1, wherein the liquid crystal display element is arranged in more than one place. 5. A liquid crystal in which an alignment film is formed on the facing surfaces of a pair of substrates on which electrode films having a predetermined pattern are formed, and a liquid crystal is sandwiched so that the facing surfaces of the pair of substrates face each other. In the method for manufacturing a display element, the thin film is formed by patterning a region in which a large number of them are arranged in substantially the same pattern and dispersed according to a certain degree of regularity, or a region excluding the region, on the opposing surfaces of the one or both substrates. Then, after forming a thin film for controlling an alignment film having an interface free energy different from that of the facing surface of the substrate, an alignment film of an incompatible polymer alloy is formed on the facing surface of the substrate on which the thin film for controlling the alignment film is formed. A method for manufacturing a liquid crystal display device, the method comprising: 6. The liquid crystal is sandwiched between the pair of substrates, and the substrates are arranged to face each other, and then heated until the liquid crystal is in an isotropic state, and then cooled to room temperature.
A method for manufacturing a liquid crystal display device according to item 1.