JP3205502B2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wide viewing angle type liquid crystal display device, and more particularly, to a liquid crystal display device having an axially symmetric liquid crystal region.

[0002]

2. Description of the Related Art Liquid crystal display devices are used in portable display devices, such as personal computers and word processors, because of their low power characteristics. For these uses, a TN (twisted nematic) liquid crystal display device using a nematic liquid crystal is widely used. However, the TN liquid crystal display device has a problem that the viewing angle is narrow.

A viewing angle characteristic of a conventional TN type liquid crystal display device will be described with reference to FIG. The liquid crystal molecules 9 of the TN type liquid crystal display device are pretilted in a certain direction in the initial alignment state (FIG. 1A), and by applying a voltage between the substrates 1 and 2, all the liquid crystal molecules 9 9 rises in a pre-tilt direction determined in advance. At this time, FIG.
In the halftone state of (b), when the liquid crystal cell is observed from different viewing angles indicated by arrows A and B, apparent light transmittances are different. Further, when the viewing angle is changed in the direction of arrow A, a phenomenon of reversing the contrast is observed, and a phenomenon of significantly lowering the display quality occurs.

(Conventional wide viewing angle technology) The following method has been proposed as a method for improving narrow viewing angle characteristics of a TN type liquid crystal display device.

Method 1: As a display mode that does not require a polarizing plate and does not require an alignment treatment, a liquid crystal cell has a liquid crystal region surrounded by a polymer wall and utilizes the birefringence of liquid crystal. A method of electrically controlling the transparent or cloudy state has been proposed. This display mode basically matches the ordinary light refractive index of liquid crystal molecules with the refractive index of the supporting medium,
When a voltage is applied and the alignment of the liquid crystal molecules is aligned, a transparent state is displayed, and when no voltage is applied, a light scattering state due to disorder of the alignment of the liquid crystal molecules is displayed.

As a method of manufacturing the above-mentioned liquid crystal display device, Japanese Patent Laid-Open Publication No. Sho 61-502128 discloses a method in which a liquid crystal is mixed with a photocurable resin or a thermosetting resin, and then the resin is cured to form the liquid crystal. A method of forming liquid crystal droplets in a resin by precipitation is disclosed.

Further, a liquid crystal display device of a wide viewing angle mode in which the above liquid crystal display device and a polarizing plate orthogonal to each other are combined is disclosed in JP-A-4-338923 and JP-A-4-21.
No. 2928. Since these display modes utilize the depolarization due to the scattering phenomenon, the light transmittance does not exceed 50% (the transmittance of two polarizing plates in a parallel Nicol state) in principle.

Method 2: As a method for improving the viewing angle characteristics of a liquid crystal display device using a non-scattering type polarizing plate, see Japanese Patent Application Laid-Open No. 5-27.
No. 242 discloses a display mode using a composite material of a liquid crystal and a polymer material by phase separation from a mixture of a liquid crystal and a photocurable resin. In this method, the alignment state of the liquid crystal domains is disturbed by the generated polymer, and the liquid crystal molecules rise in different domains when a voltage is applied. Therefore, the apparent transmittance viewed from each direction is different. Since (△ nd is averaged), the viewing angle characteristics in the halftone state are improved.

Method 3: Recently, the present inventors have disclosed liquid crystal display devices having extremely excellent viewing angle characteristics in JP-A-6-301015 and JP-A-7-120728. These liquid crystal display devices are manufactured as follows. By irradiating the precursor mixture of the liquid crystal material and the photocurable resin in the liquid crystal cell with a photomask or the like, the liquid crystal regions substantially surrounded by the polymer regions are regularly arranged corresponding to the pixel regions. Formed. The liquid crystal molecules in the liquid crystal region (picture element region) are oriented in an axially symmetrical shape (such as a spiral shape). By applying a voltage to this liquid crystal region,
The axisymmetric orientation changes to a homeotropic state. The liquid crystal region of the liquid crystal display device of this axis symmetric alignment mode is in an alignment state as shown in FIG. As shown in FIG. 2A, when the liquid crystal molecules 9 are oriented axially symmetric with respect to the symmetry axis 6, the light rays in the viewing angle directions A and B can be obtained even in the halftone state (FIG. 2B). Since the transmittance is averaged, the light transmittance is equal in both directions A and B, and the viewing angle characteristics are improved compared to the TN type. In order to improve the viewing angle characteristics of the liquid crystal display device by controlling the alignment state of the liquid crystal molecules, the liquid crystal molecules may be aligned in two or more directions on at least one substrate in the picture element. An axially symmetric orientation is more preferred.

Method 4: Further, the present inventors formed a crystalline polymer film having a spherulite structure on the surface of the substrate, and used a wide viewing angle display mode utilizing an axially symmetric alignment regulating force of the spherulite structure. Japanese Patent Laid-Open No. 7-234407 discloses a liquid crystal display device.

Method 5: A liquid crystal display device in which an alignment film is applied on a substrate and liquid crystal molecules are aligned in random directions without performing an alignment treatment such as rubbing is disclosed in JP-A-6-194655.
No. 6,086,045.

The liquid crystal display devices obtained by the above methods 2, 4, and 5 have a problem that disclination lines are generated in the liquid crystal region and the contrast is low. On the other hand, the liquid crystal display device obtained by the above method 3 has the best balance of display characteristics such as contrast and brightness.

[0013]

However, when the liquid crystal display device of the axially symmetric alignment mode is manufactured by using the above method 3, a liquid crystal region having an alignment other than the axially symmetric alignment is formed in the peripheral region of the display region 72. In some cases, the axis of symmetry of the axially symmetric orientation may be formed at a position shifted from the center of the picture element region. The inventor of the present application has studied the cause and found the following.

As shown in FIG. 8, a conventional liquid crystal display 8
0 has an intermediate area 86 between the display area 82 and the seal area 84. When a liquid crystal display device of an axially symmetric alignment mode is manufactured by the above method 3, a polymer region is formed so as to surround the pixel region of the display region 82, but the intermediate region 86 is formed.
Does not form a polymer region. Accordingly, during the phase separation process of the precursor mixture, the composition of the liquid crystal phase (nematic phase) and the composition of the polymer phase (isotropic phase) are changed to the display region 82 and the intermediate region 86.
And different. As a result, the orientation of the liquid crystal region formed in the peripheral region of the display region 82, that is, in the region close to the intermediate region 86, is not uniform, causing the above-described display failure.

The inventors of the present invention have proposed a method for manufacturing the liquid crystal display device of the above (3), in which each pixel region 8
A precursor mixed portion in which a liquid crystal material and a photocurable resin are mixed is injected into a cell using a substrate having a polymer wall 88 (lower than the cell gap) formed of a resist material around the periphery of 7 and is formed of a resist. Japanese Patent Application No. 6-23374 discloses a method of forming a polymer region by phase separation so as to cover a polymer wall.
No. 4. Also in this method, there is a problem that the distribution of the composition is not uniform in the phase separation process between the intermediate region and the display region.

When a spacer used to maintain a gap (cell gap, thickness of a liquid crystal layer) between a pair of substrates constituting a liquid crystal display device is present in a picture element region, the axisymmetric alignment is disturbed and the display quality is reduced. descend. As a method for solving this problem, the applicant of the present application applied for a method of fixing a spacer in a polymer wall formed so as to surround a liquid crystal region (pixel region) in Japanese Patent Application No. 7-234407. ing.

However, in this method, since the polymer wall (resist wall) for fixing the spacer does not exist in the intermediate region 86 between the display region and the seal region, the cell in the peripheral region of the display portion is not provided. There is a problem that the gap is not maintained stably. Therefore, especially when used as a display device for pen input or when a stress is applied to the display unit, the spacer is not present in the intermediate region 86, and the polymer region is not formed. Area 82
In the peripheral region of, the display quality is deteriorated due to the change of the cell gap.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a wide viewing angle type liquid crystal display device having an axially symmetric liquid crystal region with excellent display quality. It is in.

[0019]

According to a liquid crystal display device of the present invention, at least one of a pair of transparent substrates, a liquid crystal layer sandwiched between the pair of substrates, and the pair of substrates are bonded to each other. A sealing region surrounding the liquid crystal layer, wherein the liquid crystal layer substantially includes a liquid crystal region regularly formed so as to correspond to each of a plurality of picture element regions arranged in a matrix and the liquid crystal region. A liquid crystal display device, wherein the liquid crystal molecules in the liquid crystal region are axially symmetrically aligned, and the liquid crystal layer has a display region including the plurality of picture element regions. The plurality of picture element regions are provided in a region between the seal region and the seal region.
A plurality of pseudo picture element areas arranged in a matrix at the same pitch as the liquid crystal area and a liquid crystal area regularly formed so as to correspond to each of the plurality of pseudo picture element areas. and a polymer region surrounding the above object is met.

[0020]

[0021]

It is preferable that the spacer for maintaining the interval between the pair of substrates is fixed by a polymer wall formed outside the plurality of picture element regions and the plurality of pseudo picture element regions. Preferably, the polymer region is formed so as to cover the polymer wall.

It is preferable that the apparatus further comprises means for applying a voltage to the liquid crystal regions of the plurality of pseudo picture element regions.

In one embodiment, the liquid crystal display device comprises a plurality of picture element electrodes, a switching element for switching a signal voltage applied to the plurality of picture element electrodes, and a signal voltage applied to the switching element. Means for applying a voltage to the liquid crystal regions of the plurality of pseudo picture element regions, the signal lines being provided directly to the source lines.

It is preferable that a light-shielding film is formed in a region between the display region and the seal region.

It is preferable that the liquid crystal molecules in the liquid crystal region of the pseudo picture element region have an axially symmetric orientation. Further, in the method for manufacturing a liquid crystal display device of the present invention, at least one of the pair of substrates is transparent, a liquid crystal layer sandwiched between the pair of substrates, and the pair of substrates is bonded to each other to form the liquid crystal layer. A method of manufacturing a liquid crystal display device having a surrounding sealing region,
On one substrate, a plurality of pixel electrodes are arranged in a matrix in a display area, and a plurality of pseudo electrodes are arranged in a matrix between the display area and the seal area at the same pitch as the pixel electrodes. Arranging, forming a polymer region that substantially surrounds each of the pixel electrodes and each of the pseudo electrodes, and forming the polymer region substantially surrounding each of the pixel electrodes and each of the pseudo electrodes; Providing a sealing material except for the injection port, bonding the other substrate with the sealing material, and pouring a precursor material having a liquid crystal material and a photoinitiator between a pair of substrates bonded to each other. A step of injecting from the inlet, and a step of forming the liquid crystal phase corresponding to each picture element electrode and each pseudo electrode by lowering the temperature to separate the phase after the precursor is made a homogeneous phase at a compatibilization temperature or higher. If, comprising the steps of axisymmetric alignment state of the liquid crystal molecules of the liquid crystal phase, by irradiating light to the liquid crystal phase, and fixing the axisymmetric orientation of the liquid crystal phase, a.

The operation will be described below.

The liquid crystal display device according to the present invention comprises a liquid crystal layer in which a liquid crystal region in which liquid crystal molecules are aligned in an axially symmetric manner is substantially surrounded by a polymer region, and which is regularly formed corresponding to a picture element region. Have. The polymer wall that controls the region where the polymer region is formed is formed not only around the pixel region but also in an intermediate region between the display region and the seal region.
Since the polymer wall formed in the intermediate region has the same function as the polymer wall provided in the display region, a liquid crystal layer having the same structure as the display region is also formed in the intermediate region. In the present specification, a region formed in the middle region of the liquid crystal layer and having the same configuration as the pixel region is referred to as a pseudo-pixel region. As a result, the composition in the phase separation process for forming the liquid crystal region substantially surrounded by the polymer region can be made the same in the display region and the intermediate region. Therefore, a liquid crystal region having a uniform axially symmetric alignment can be formed even in a peripheral region of the display region.

Further, by fixing the bead-shaped spacer using the polymer wall, the spacer is arranged outside the pixel region and the spacer is also arranged in the intermediate region, so that the cell gap in the intermediate region can be stabilized. Can be maintained.

[0030]

Embodiments of the present invention will be described below.

FIG. 3 is a top view of a peripheral region of the active matrix substrate 30 used in the liquid crystal display device according to the present invention. Display area 3 of active matrix substrate 30
A polymer wall 48 and a dummy electrode 47 a substantially surrounded by the polymer wall 48 are formed in an intermediate region 36 between the second region 2 and the seal region 34.

In the (polymer wall) display area 32, a picture element electrode 37a and a thin film transistor (hereinafter abbreviated as TFT) 37
A polymer wall 38 is formed on the substrate 31 so as to surround the region where b is formed. This polymer wall 38
(1) To control the position where the polymer region substantially surrounding the liquid crystal region having an axially symmetric alignment formed in each pixel region is formed, and (2) fixing the spacer outside the pixel region It is provided for you. In the specification of the present application, a minimum unit for performing display is called a pixel region, and in an active matrix liquid crystal display device, a pixel electrode, a counter electrode, and a liquid crystal layer sandwiched between these electrodes are used. Refers to the area that contains. When a black mask is used, the size of the pixel region is determined by the size of the opening of the black mask. As shown in FIG. 3, the polymer wall 38 substantially surrounding the picture element region 37 has a picture element electrode 37a and a TF
It is preferably formed so as to surround T37b. However, it may be formed so as to surround only the pixel electrode 37a.
A polymer wall may be formed so as to form the above liquid crystal region.

The operation of the polymer wall 38 will be described. When a precursor mixture, which is a mixture of a liquid crystal material and a photocurable resin, is subjected to light irradiation or temperature control (cooling), it undergoes phase separation into a liquid crystal phase (nematic phase) and a polymer phase (isotropic phase). . At this time, the polymer phase is formed at the position of the polymer wall 38 made of a material having a high affinity (good wettability) with the polymer phase. As a result, the liquid crystal phase is formed in a region surrounded by the polymer wall. Formed within. The height of the polymer wall 38 is set lower than the cell gap so as not to hinder the injection of the precursor material.

In the phase separation process, the fraction of the photocurable resin contained in the liquid crystal phase and the fraction of the liquid crystal material contained in the polymer phase decrease as the phase separation progresses. In the final stage of the phase separation, the photocurable resin in the precursor mixture is cured by light irradiation to form a liquid crystal region composed of a liquid crystal material and a polymer region composed of the cured photocurable resin. The liquid crystal layer formed by this phase separation has a structure as shown in FIG.

As in the conventional liquid crystal display device, the intermediate region 3
If no polymer region is formed in 6, the precursor mixture
The composition of the liquid crystal phase and the polymer phase due to the progress of the phase separation is different between the display region 32 and the intermediate region 36. Therefore, in a region near the intermediate region 36 of the display region 32, there is a problem that a liquid crystal region similar to the central portion of the display region 32 is not formed due to the composition shift. For example, a liquid crystal region having an orientation other than the axially symmetric orientation may be formed, or the axis of symmetry of the axially symmetric orientation may be formed at a position shifted from the center of the pixel region.

However, when the active matrix substrate 30 of the present invention is used, the polymer wall 38 of the display area 32 is used.
The same polymer wall 48 is also formed in the intermediate region 36, so that the pixel region 37 of the display region 32
Is formed, the change in the composition accompanying the progress of the phase separation is caused by the display region 32 and the intermediate region 3.
6 is almost the same. As a result, in the peripheral area of the display area 32, the same liquid crystal area as the central part of the display area 32 is formed, and the display quality is improved.

Next, a method for fixing the spacer outside the picture element region by the polymer wall will be described.

If a bead-shaped spacer (hereinafter, abbreviated to bead) used for maintaining the cell gap exists in the picture element region, it may be difficult to form an axially symmetric orientation. Therefore, the beads are fixed outside the pixel region by using the polymer walls 38 and 48.

A method for fixing beads by the polymer walls 38 and 48 will be described with reference to FIGS. 5A and 5B. FIG. 5 is a schematic diagram showing a configuration of the polymer walls 38 and 48 of the active matrix substrate 30,
(A) is a top view, and (b) is a 5b-5b 'sectional view of (a). Since the configurations of the polymer walls 38 and 48 are the same, they are represented as a polymer wall 57, and a region surrounded by the polymer wall 58 is represented as a pixel region 57. The pixel region 57 corresponds to a region including the pixel electrode 37a and the TFT 37b, or a region including the dummy electrode 47a. In the case of this example, the size of the pseudo picture element region 47 is defined by the size of the dummy electrode 47a.

The beads 59 are sprayed on the substrate 31 by a conventional method, and a first resist layer is formed so as to cover the beads 59. Thereafter, the first resist layer is patterned by a photolithography process to form a first resist wall 58a to which beads located between the picture element regions 57 are fixed. Thereafter, a second step is performed so as to completely cover the beads 59.
A resist layer is formed, and a second resist wall 58b is similarly formed. By making the difference between the pattern width of the first resist layer and the pattern width of the second resist layer larger than the diameter of the beads 59, the side surfaces of the beads 59 can be completely covered with the second resist layer 58a. With the above configuration, the side surfaces of the beads 59 are prevented from coming into contact with the precursor mixture, and the position of the polymer region formed during the phase separation of the precursor mixture is controlled by the second resist wall 58b. Is done. In the above example, the first resist wall 58a and the second resist wall 58a
Although the polymer wall 58 was formed by the resist wall 58b,
It can also be formed using a material other than the resist material. Alternatively, a material in which beads 59 are mixed and dispersed in advance in the material for forming the first resist layer can be used. Also,
For patterning of the polymer wall, a printing technique can be used other than the photolithography technique.

According to the present invention, the polymer wall 58 to which the spacer is fixed is formed as the polymer wall 38 and the polymer wall 48 in FIG. Since the cell gap can be maintained also in the intermediate region 36, it is possible to prevent a display defect such as a color change due to a non-uniform cell gap.

(Dummy electrode) In this embodiment, the polymer wall 4
8 and a dummy electrode 47 a is formed in a region surrounded by the polymer wall 48. In the process of forming a liquid crystal region having an axially symmetric alignment by phase separation of the precursor mixture, a voltage is applied to the liquid crystal phase (liquid crystal region) to arrange the axis of symmetry of the axially symmetric alignment at the center of the liquid crystal region. it can. By forming a dummy electrode also in the peripheral region of the display region 32 and applying a voltage to the liquid crystal phase during the phase separation process, a liquid crystal region in which the position of the symmetry axis and the direction of the symmetry axis are uniform can be formed. As a result, the position of the axis of symmetry of the axially symmetric orientation of the liquid crystal region in the peripheral region of the display region 32 is shifted from the center of the picture element region due to the influence of the liquid crystal region of the intermediate region 36, or the symmetry axis is Can be prevented from tilting.

Since the light transmittance of the picture element area whose axis of symmetry is shifted from the center of the picture element area is different from the transmittance of the picture element area whose center of symmetry axis is located at the center of the picture element area, the display is performed. Is reduced. In addition, the display characteristics of a picture element region in which the axis of symmetry of the axially symmetric orientation is tilted with respect to the substrate surface differ depending on the direction in which the viewing angle is tilted. In the liquid crystal display device of the present invention, even in the peripheral region of the display region 32, a liquid crystal region having an axially symmetric orientation centered on a symmetry axis extending in a direction perpendicular to the substrate surface, which is located at the center of the pixel region, As a result, a liquid crystal display device having excellent display quality is provided.

Since the dummy electrode 47a is an electrode provided to form a liquid crystal region similar to the liquid crystal region formed in the display region 32, the dummy electrode 47a does not need to have the same shape as the pixel electrode 37a, and is shown in FIG. It may be a simple square as shown. However, in order to make the change in the composition of each phase in the phase separation process substantially the same as the display region, the ratio of the size of the region where the liquid crystal region is formed to the size where the polymer region is formed is: Preferably, their ratio in the display area 32 is substantially the same. Therefore, the pseudo picture element area 47
Are preferably formed at the same pitch as the picture element region. Here, a delta arrangement will be described as an example, but the present invention is not limited to this and can be applied to various picture element arrangements.

Since the intermediate region 36 does not contribute to the display, it is not necessary to provide the TFT 37b for the dummy electrode 47a, and it is not necessary to connect the TFT 37b to the gate bus line (scanning line) 42. Therefore, as shown in FIG. 3, the dummy electrodes 47a are preferably provided at the same pitch as the pixel electrodes 37a, and are preferably rectangular electrodes. As shown in FIG. 4, the dummy electrode 47a is connected to the source bus line (signal line) 4
4 directly. Further, the formation of the dummy electrode 47a can be performed in the same step and using the same material as the formation of the picture element electrode 37a. Further, the dummy electrode is preferably a transparent electrode in order to perform an ultraviolet irradiation step for fixing the axially symmetric orientation.

(Black Mask) In the peripheral region of the intermediate region 36, the axially symmetric alignment is disturbed by the influence of the sealing material forming the sealing region 34 and the liquid crystal layer formed between the sealing material and the polymer wall 48. Since a liquid crystal region may be formed, it is preferable to cover the entire or peripheral region of the intermediate region 36 with a black mask provided on the counter substrate.

(Driving Method) The liquid crystal display device of the present invention uses a simple matrix drive, a-Si TFT, p-Si
It can be driven by a driving method such as active driving using a switching element such as a TFT or MIM. An appropriate driving method may be selected depending on the use of the liquid crystal display device.

(Substrate Material) As a substrate material, glass or polymer film which is a transparent solid can be used. As the plastic substrate, a material that does not absorb visible light is preferable, and PET (polyethylene terephthalate),
Acrylic polymers, polystyrene, polycarbonate and the like can be used.

Further, two types of these substrates may be combined to form a cell with a different type of substrate. In addition, two substrates having the same thickness but different thicknesses may be used in combination. In the case of a plastic substrate, a liquid crystal display device in which a polarizing plate is integrated can be formed by giving the substrate itself a polarizing ability.

[0050]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example 1) A counter substrate and an active matrix substrate constituting a liquid crystal cell were manufactured as follows. A counter electrode made of ITO (a mixture of indium oxide and tin oxide, 150 nm) is formed on a glass substrate having a thickness of 1.1 mm, and a black mask is formed in which a region other than a pixel region and a sealing region are used as a light shielding portion. .

An active matrix substrate having dummy electrodes connected to the source bus lines shown in FIG. 3 was manufactured by a known method. The dummy electrode was formed in the step of forming the picture element electrode by using ITO in the same manner as the picture element electrode. On the surface of the obtained active matrix substrate, beads having a diameter of 4 μm (Micropearl: manufactured by Sekisui Chemical Co., Ltd.) are sprayed, and an OMR-83 (manufactured by Tokyo Ohka Co.) resist is applied thereon. By performing the above steps, a polymer wall 58 having the structure shown in FIG. 5 is formed. Next, a seal material is screen-printed using a screen printing mask 60 having a seal pattern 64 shown in FIG. The seal pattern 64 surrounds an area excluding the injection port 69. Note that the seal material is not printed on the area other than the seal pattern 64 (including the display area 62 and the area 66 where the inner polymer wall of the intermediate area is formed). As described above, the obtained opposing substrate and the active matrix substrate are adhered and fixed by the sealing material to obtain a cell. Note that a color liquid crystal display device can be manufactured by forming a color filter in a picture element region of the counter substrate as necessary.

In the obtained cell, 0.20 g of R-684 (manufactured by Nippon Kayaku Co., Ltd.), 0.20 g of p-phenylstyrene,
0.10 g of a compound A represented by the following (Chemical formula 1) and a liquid crystal material ZLI-4792 (manufactured by Merck Ltd .: Δn = 0.094:
A precursor mixture consisting of 4.5 g of S-811 (adjusted by S-811) and 0.0259 of a photoinitiator Irgacure 651 (manufactured by Ciba-Geigy) so that the chiral pitch becomes 90 ° was injected by a vacuum injection method.

[0054]

Embedded image

Thereafter, the temperature of the cell is once raised to a temperature equal to or higher than the compatibilization temperature of the precursor mixture (100 ° C.) to make it a uniform phase, and then the temperature is lowered to cause phase separation, and the liquid crystal phase (liquid crystal region) becomes a pixel. There was one for the area. In this state, a voltage (60 Hz, an effective voltage of 5 V) was applied between the counter electrode, the pixel electrode, and the dummy electrode, and the alignment of the liquid crystal molecules in the liquid crystal region was changed to an axially symmetric alignment state.

Further, in order to fix the axially symmetric orientation state in this state, ultraviolet rays were irradiated from the active matrix substrate side under a high-pressure mercury lamp at 3 mW / cm ² (intensity at a wavelength of 365 nm) for 40 minutes.

When the obtained liquid crystal cell was observed with a polarizing microscope (paranicol), as shown in FIG.
It was confirmed that a liquid crystal region having an axis of symmetry 76 and having an axially symmetric orientation was formed in the center of the sample. In particular, even in the peripheral area of the display area, no axially symmetrical alignment unevenness occurred, and no color change due to a change in the cell gap occurred.

Two polarizing plates were attached on both sides of the obtained liquid crystal cell so that the polarization axes were orthogonal to each other, thereby completing a liquid crystal display device. In addition, from the viewpoint of viewing angle characteristics, it is preferable to provide a polarizing plate such that the polarizing axes are located in the vertical and horizontal directions of the display surface. The obtained liquid crystal display device provided a uniform display even when the viewing angle direction was changed.

As described above, by forming a polymer wall similar to the display region in the intermediate region, a uniform axially symmetric alignment state is achieved, and a uniform display region can be formed.

Comparative Example 1 As a comparative example, the same active matrix substrate as in Example 1 was used, and a polymer wall was formed only in the display region without forming a polymer wall in the intermediate region. Hereinafter, a liquid crystal display device was manufactured in the same manner as in Example 1. The liquid crystal display device of this comparative example has the configuration shown in FIG.

As a result of observing the obtained liquid crystal display device with a microscope, 1 to 2% of the picture element regions in which the axial positions of the axisymmetric alignment were shifted were observed in the peripheral region of the display region. Further, a slight color change was observed in the peripheral area of the display area.

[0062]

According to the present invention, a wide viewing angle type liquid crystal display device having an axially symmetric liquid crystal region with excellent display quality is provided. Therefore, it is suitably used for a display device which can be viewed by many people. Further, the liquid crystal display device of the present invention has an advantage that even if the liquid crystal display device is used in a display device or the like for pen input, color unevenness or the like does not occur because the cell gap does not fluctuate due to external stress.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing viewing angle characteristics of a conventional TN type liquid crystal display device.

FIG. 2 is a schematic diagram illustrating viewing angle characteristics of a liquid crystal display device in an axisymmetric alignment mode.

FIG. 3 is a top view of a peripheral region of an active matrix substrate 30 used in the liquid crystal display device according to the present invention.

FIG. 4 is a schematic diagram showing a configuration of a dummy electrode in an active matrix substrate used in a liquid crystal display device according to the present invention.

FIG. 5 is a schematic diagram showing a configuration of a polymer wall for fixing a spacer in an active matrix substrate used in a liquid crystal display device according to the present invention.

FIG. 6 is a top view showing a screen printing mask used in an embodiment of the present invention.

FIG. 7 is a schematic diagram showing a result of observation of a picture element region of the liquid crystal display device according to the first embodiment of the present invention by a polarizing microscope.

FIG. 8 is a schematic diagram illustrating a configuration of a liquid crystal display device formed in Comparative Example 1.

[Explanation of symbols]

 1, 2 Substrate 6, 76 Symmetry axis 7 Polymer region 8 Liquid crystal region 9 Liquid crystal molecule 30 Active matrix substrate 31 Substrate 32, 82 Display region 34, 84 Seal region 36, 86 Intermediate region 37, 57, 87 Pixel region 37a Picture Element electrode 37b Thin film transistor 47, 77 Pseudo picture element area 47a Dummy electrode 48, 58, 88 Polymer wall 58a, 58b Resist wall 59 Spacer 60 Screen printing mask 62 Display area 64 Seal pattern 66 Intermediate area inner polymer wall is formed Area 69 Inlet 80 Conventional liquid crystal display

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-7-120728 (JP, A) JP-A-7-152024 (JP, A) JP-A-5-241153 (JP, A) JP-A-7-120 333654 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02F 1/1334 G02F 1/136

Claims (8)

(57) [Claims] 1. A pair of substrates, at least one of which is transparent;
A liquid crystal layer sandwiched between the pair of substrates; and a seal region that adheres the pair of substrates to each other and surrounds the liquid crystal layer. The liquid crystal layer includes a plurality of pictures arranged in a matrix. A liquid crystal region regularly formed so as to correspond to each of the elementary regions and a polymer region substantially surrounding the liquid crystal region, and liquid crystal molecules in the liquid crystal region are axially symmetrically aligned; A liquid crystal display device, wherein the liquid crystal layer includes a same pixel as the plurality of picture element regions in an area between the display area including the plurality of picture element areas and the seal area.
A plurality of pseudo picture element areas arranged in a matrix in a matrix, and substantially surrounding the liquid crystal area and the liquid crystal area regularly formed so as to correspond to each of the plurality of pseudo picture element areas. A liquid crystal display device having a polymer region. 2. A spacer for maintaining a distance between the pair of substrates, in claim 1 which is secured by the plurality of picture element regions and the plurality of pseudo-picture element regions outside the formed polymer wall The liquid crystal display device according to the above. 3. The liquid crystal display device according to claim 2, wherein the polymer region is formed so as to cover the polymer wall. 4. A having a means for applying a voltage to the liquid crystal region of said plurality of pseudo-picture element regions, the liquid crystal display device according to any one of claims 1 to 3. 5. The liquid crystal display device, comprising: a plurality of picture element electrodes; a switching element for switching a signal voltage applied to the plurality of picture element electrodes; and a signal for supplying the signal voltage to the switching element. The liquid crystal display device according to claim 4 , further comprising a line, wherein the means for applying a voltage to the liquid crystal region of the plurality of pseudo picture element regions is directly connected to the source line. Wherein said the region between the display region and the sealing region, the liquid crystal display device according to claim 1, the light-shielding film is formed 5. 7. A liquid crystal display device according to any one of the pseudo liquid crystal molecules in the liquid crystal region of the pixel region claims 1 that the axisymmetric orientation 6. 8. A pair of substrates at least one of which is transparent;
A method for manufacturing a liquid crystal display device having a liquid crystal layer sandwiched between a pair of substrates, and a sealing region that adheres the pair of substrates to each other and surrounds the liquid crystal layer. Arranging a plurality of pixel electrodes in a matrix in a display region, and arranging a plurality of pseudo electrodes in a matrix between the display region and the seal region at the same pitch as the pixel electrodes; Forming a polymer region that substantially surrounds each of the pixel electrodes and each of the pseudo electrodes; and excluding an injection port in the seal region on one of the substrates on which each of the pixel electrodes and each of the pseudo electrodes are formed. Providing a sealing material and bonding the other substrate with the sealing material; and injecting a precursor material having a liquid crystal material and a photoinitiator from the injection port between the pair of substrates bonded to each other. , The precursor, after a homogeneous phase as a more miscible temperature,
Lowering the temperature and separating the phases to form a liquid crystal phase corresponding to each pixel electrode and each pseudo electrode; a step of setting the liquid crystal molecules of each liquid crystal phase to an axially symmetric alignment state; Irradiating the liquid crystal phase to fix the axially symmetric alignment state of each liquid crystal phase.