JP2001056468A - Liquid crystal display device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device and its production to avoid disturbance in the axially symmetric alignment of liquid crystal molecules while using spacer beads to regulate the cell gap, namely, to realize wide viewing angle characteristics while decreasing the production cost. SOLUTION: The liquid crystal display device consists of a first substrate 100a, a second substrate 100b disposed facing the first substrate, and a liquid crystal layer 30 disposed between the first and second substrates. Polymer walls 16 having inclined faces to the surface of the substrate are formed on the first substrate. The liquid crystal layer has a plurality of liquid crystal regions divided by the polymer walls. Spacer beads 20 to regulate the gap of the liquid crystal layer are present on the tops of the polymer walls and on one inclined face of the polymer wall in the four side lines of the polymer wall surrounding the liquid crystal region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device and a method for manufacturing the same. In particular, the present invention relates to a liquid crystal display device having liquid crystal molecules axially symmetrically aligned in a liquid crystal region divided by polymer walls, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a display device using an electro-optic effect, a TN (twisted nematic) or STN (super twisted nematic) type liquid crystal display device using a nematic liquid crystal has been used. Techniques for increasing the viewing angle of these liquid crystal display devices have been energetically developed.

As one of the techniques for increasing the viewing angle of a TN type liquid crystal display device which has been proposed so far, JP-A-6-301 discloses
No. 015 and JP-A-7-120728 disclose a liquid crystal display device having axisymmetrically aligned liquid crystal molecules in a liquid crystal region divided by polymer walls, a so-called ASM.
(Axially Symmetrically al
A liquid crystal display device of an ignited Microcell mode is disclosed. A liquid crystal region substantially surrounded by polymer walls is typically formed for each pixel. ASM
In the liquid crystal display device of the mode, since the liquid crystal molecules are oriented axially symmetrically, even if the observer looks at the liquid crystal display device from any direction,
The change in contrast is small, that is, it has a wide viewing angle characteristic.

[0004] The ASM mode liquid crystal display device disclosed in the above publication is manufactured by subjecting a mixture of a polymerizable material and a liquid crystal material to polymerization induced phase separation.

A method of manufacturing a conventional ASM mode liquid crystal display device will be described with reference to FIGS.
First, a substrate having a color filter and electrodes formed on one surface of a glass substrate 908 is prepared (step (a)). In addition,
The electrodes and the color filters formed on the upper surface of the glass substrate 908 are not shown for the sake of simplicity. The method for forming the color filter will be described later.

Next, on the surface of the glass substrate 908 on which the electrodes and the color filters are formed, polymer walls 917 for axisymmetrically aligning the liquid crystal molecules are formed, for example, in a lattice shape (step (b)). . After spin-coating the photosensitive resin material, it is exposed through a photomask having a predetermined pattern and developed to form a lattice-shaped polymer wall. The photosensitive resin material may be a negative type or a positive type.
Although the number of steps for forming a separate resist film is increased, the resist film can be formed using a non-photosensitive resin material.

On the top of the obtained polymer wall 917, columnar projections 920 are discretely formed by patterning (step (c)). The columnar protrusions 920 are also formed by exposing and developing a photosensitive resin material.

Next, the polymer wall 917 and the columnar protrusion 92
The surface of the glass substrate 908 on which 0 is formed is covered with a vertical alignment agent 921 such as polyimide (step (d)). on the other hand,
The glass substrate 902 on the opposite side on which the electrodes are formed is also covered with the vertical alignment agent 921 (steps (e) to (f)).

The two substrates obtained are bonded together with the surface on which the electrodes are formed facing inward to form a liquid crystal cell (step (g)). The distance (cell gap; thickness of the liquid crystal layer) between the two substrates is defined by the sum of the heights of the polymer wall 917 and the columnar protrusion 920.

A liquid crystal material is injected into the gap between the obtained liquid crystal cells by a vacuum injection method or the like (step (h)). Finally,
For example, by applying a voltage between one of the opposed electrodes, the liquid crystal molecules in the liquid crystal region 916 are axially symmetrically controlled (step (i)). The liquid crystal molecules in the liquid crystal region divided by the polymer wall 917 are oriented axially symmetric with respect to an axis 918 (perpendicular to both substrates) indicated by a broken line in FIG.

FIG. 8 shows a sectional structure of a conventional color filter.

On a glass substrate 1001, a black matrix (BM) 10 for shielding a gap between colored patterns from light.
02 and red, green, and blue (R, G, and B) colored resin layers 1003 corresponding to the respective picture elements. On top of these,
An overcoat (OC) layer 1004 made of an acrylic resin or an epoxy resin and having a thickness of about 0.5 to 2.0 μm is formed to improve smoothness and the like. Furthermore, an indium tin oxide (ITO) film 1005 of a transparent signal electrode is formed thereon. The BM film 1002 is generally formed of a metal chromium film having a thickness of about 100 to 150 nm. As the colored resin layer 1003, a resin material colored with a dye or a pigment is used, and its film thickness is generally about 1 to 3 μm.

As a method of forming a color filter, a method of patterning a photosensitive colored resin layer 1003 formed on a substrate 1001 by using a photolithography technique is used. For example, by using a photosensitive colored resin material of each color of red (R), green (G), and blue (B), forming, exposing, and developing the photosensitive colored resin (total three times) , R, G, B color filters can be formed. The method of forming a photosensitive colored resin layer is as follows:
There are a method of applying a liquid photosensitive coloring resin material (diluted with a solvent) to a substrate by a spin coating method and the like, and a method of transferring a photosensitive coloring resin material formed into a dry film. The above-described ASM mode liquid crystal display device is manufactured using the color filters thus formed, whereby a color liquid crystal display device having a wide viewing angle characteristic can be obtained.

[0014]

However, the above-mentioned ASM mode liquid crystal display device and its manufacturing method include:
There are the following issues.

That is, in the above-described ASM mode liquid crystal display device, the columnar projections 9 are formed in order to define the cell gap.
Although 20 is used, it is necessary to use a high-cost photolithography method due to this. It is known that the use efficiency of a resist material is extremely low in a method using a spin coater as a resist coating method, and an expensive laminating apparatus needs to be introduced in a method of laminating a dry film resist. In addition, as the size of a panel to be manufactured increases, the cost related to exposure, for example, the cost of a photomask and the cost of an irradiation lamp also increase rapidly.

[0016] For this reason, attempts have been made to define the cell gap by using spacer beads that can be manufactured at a lower cost. However, if the spacer beads exist in the picture element, the display quality of the liquid crystal display device may be adversely affected. For example, in a normally white mode liquid crystal display device, if a spacer bead is present in a picture element, light passing through the spacer bead is always blocked, which substantially lowers the aperture ratio. Further, in a normally black mode liquid crystal display device, light passing through the spacer beads during black display is not completely blocked, so that light leakage occurs. Furthermore, it has been confirmed that if the remaining spacer beads and the like are non-uniformly aggregated and distributed in a picture element, the orientation of liquid crystal molecules is affected and disclination occurs. In any of these cases, there is a problem that the contrast is reduced.

In particular, in the case of a liquid crystal display device utilizing the ASM mode, the presence of spacer beads in a picture element disturbs the axially symmetric alignment of liquid crystal molecules and impairs the wide viewing angle characteristics. There must be no spacer beads inside.

The present invention has been made to solve the above-mentioned problem, and does not disturb the axially symmetric alignment of liquid crystal molecules while using spacer beads for defining a cell gap, that is, a reduction in manufacturing cost. It is an object of the present invention to provide a liquid crystal display device having a wide viewing angle characteristic and a method of manufacturing the same while achieving the above.

[0019]

A liquid crystal display device according to the present invention comprises a first substrate, a second substrate disposed opposite to the first substrate, and a first substrate and a second substrate. A liquid crystal layer disposed between the first substrate and the first substrate, the liquid crystal layer having a surface inclined with respect to the surface of the substrate, A spacer bead having a plurality of liquid crystal regions divided by a liquid crystal layer and defining a gap between the liquid crystal layers is formed on the top of the polymer wall and the polymer wall 4 surrounding the liquid crystal tilt region.
One of the sides is characterized by being present on the inclined surface of the polymer wall, whereby the object is achieved.

Preferably, the length of the inclined surface of the polymer wall is larger than the diameter of the spacer bead.

[0021] The movement of the spacer beads may be restricted by a curable resin for fixing the liquid crystal molecules that are axially symmetrically aligned.

The liquid crystal cell may be used standing upright so that the inclined surface of the liquid crystal region where the spacer beads are present faces downward.

The method for manufacturing a liquid crystal display device according to the present invention comprises:
A substrate, a second substrate disposed opposite the first substrate, and a liquid crystal layer disposed between the first and second substrates. A method for manufacturing a liquid crystal display device having a plurality of liquid crystal regions divided by a polymer wall having a surface inclined with respect to the surface of the liquid crystal display device, comprising: forming the polymer wall on the first substrate; Dispersing spacer beads on the first substrate on which the polymer wall is formed, and then bonding a second substrate on the first substrate; and disposing the first and second substrates on the first substrate. The step of injecting a liquid crystal material in between, and the step of moving spacer beads dispersed in the liquid crystal region onto the inclined surface of the polymer wall, thereby achieving the above object. You.

The liquid crystal cell into which the liquid crystal has been injected is set substantially vertically,
A method may be used in which the spacer beads dispersed in the liquid crystal region are moved on the inclined surface of the polymer wall by applying vibration.

The liquid crystal cell into which the liquid crystal has been injected is set substantially vertically,
The method may be such that the spacer beads dispersed in the liquid crystal region by heating are moved on the inclined surface of the polymer wall.

The method further includes, following the step of moving the spacer beads dispersed in the liquid crystal region onto the inclined surface of the polymer wall, a step of mixing the liquid crystal material with the liquid crystal material and polymerizing the injected curable resin. You may.

The operation will be described below.

According to the present invention, the cell gap of the liquid crystal cell is defined by the spacer beads located on the flat surface on the top of the polymer wall. Spacer beads that do not contribute to the definition of the cell gap move on the inclined surface of one side of the polymer wall surrounding the liquid crystal region, and then form an axis-symmetric alignment fixed layer of liquid crystal molecules, and simultaneously move the spacer beads. Not fixed.

By applying light to the mixture of the liquid crystal material and the photocurable resin while applying a voltage, the photocurable resin is cured, and the liquid crystal molecules are pre-tilted axially symmetrically. Form a layer. At this time, the spacer beads moved on the slope of one side of the polymer wall are also fixed at that position.

By driving the spacer beads out of the liquid crystal region, it is possible to prevent the following adverse effects on display quality.

That is, for example, in a normally white mode liquid crystal display device, if the spacer beads exist in the picture element, the light passing through the spacer beads is always blocked, so that the aperture ratio is substantially reduced. . Further, in a normally black mode liquid crystal display device, light passing through the spacer beads during black display is not completely blocked, so that light leakage occurs. Furthermore, it has been confirmed that if the remaining spacer beads and the like are non-uniformly aggregated and distributed in the picture element, the orientation of the liquid crystal molecules is affected and disclination occurs. However, there is a problem that the contrast is reduced. In particular, in the case of a liquid crystal display device using the ASM mode,
The presence of the spacer beads in the picture element disturbs the axially symmetric alignment of the liquid crystal molecules, thereby deteriorating the wide viewing angle characteristics in addition to the problem of lowering the contrast.

As a method for moving the spacer beads, a method in which the liquid crystal cell is set upright and heating and / or vibration is applied can be used.

The direction in which the liquid crystal cell is set up is preferably the same as the direction in which the liquid crystal cell is actually used.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIGS. 1A and 1B show a liquid crystal display device 100 of Embodiment 1. FIG.

FIG. 1A schematically shows a cross section of the liquid crystal display device 100. FIG. 1B is a top view thereof, and FIG.
FIG. 3 is a cross-sectional view taken along line XY of FIG.

In the first embodiment, a configuration using a liquid crystal material having negative dielectric anisotropy and a vertical alignment film is exemplified, but the present embodiment is not limited to these.

The liquid crystal display device 100 includes a first substrate 100a
And a second substrate 100b, and a liquid crystal layer 30 made of liquid crystal molecules (not shown) having negative dielectric anisotropy disposed therebetween. The first substrate 100a is configured as follows.

On the liquid crystal side surface of the first transparent substrate 10 such as a glass substrate, a first transparent electrode 12 made of ITO (indium tin oxide) or the like is formed. Further, a polymer wall 16 made of a resin material is formed on the first transparent electrode 12, for example, in a lattice shape. The polymer wall 16 is used for the liquid crystal layer 3.
In addition to dividing 0 into a plurality of liquid crystal regions 30a, the liquid crystal device has an effect of axially symmetrically aligning liquid crystal molecules existing in the liquid crystal region 30a. That is, the liquid crystal region 30a is defined by the polymer wall 16, and the polymer wall 16 substantially surrounds the liquid crystal region 30a.

In the present embodiment, the polymer walls 16 are provided in a lattice shape corresponding to the picture element regions, but the arrangement of the polymer walls 16 is not limited to this. Further, spacer beads 20 for defining the thickness (cell gap) of the liquid crystal layer 30 are discretely provided on the top of the polymer wall 16. As shown in FIG. 1A, the polymer wall 16 has a flat top 16b and an inclined surface 16a. The inclined surface 16a
Is inclined downward from the top 16b toward the surface of the substrate 10, and the polymer wall 16 has a substantially trapezoidal cross section.

In this embodiment, the cell gap is defined by the sum of the thickness of the polymer wall 16 and the diameter of the spacer beads 20.

The spacer beads 20a also exist on the inclined surface 16a of one of the four sides of the polymer wall 16 which substantially surrounds the liquid crystal region 30a. The spacer beads 20a do not contribute to the definition of the cell gap. On the liquid crystal side surface of the first substrate 100a on which these are formed, a vertical alignment film 18 for aligning liquid crystal molecules (not shown) of the liquid crystal layer 30 includes at least the first transparent electrode 12 and the polymer wall 1.
6 is provided.

The second substrate 100b is configured as follows.

As shown in FIG. 1A, the surface of the second transparent substrate 40 such as a glass substrate on the liquid crystal layer 30 side is covered with an IT.
A second transparent electrode 42 made of O or the like is formed. Further, a vertical alignment film 48 is formed to cover the second transparent electrode 42.

The first electrode 12 for driving the liquid crystal layer 30
As the configuration and the driving method of the second electrode 42, a known electrode configuration and a driving method can be used. For example, an active matrix type or a simple matrix type can be applied. Further, a plasma address type can be applied. In this case, the first electrode 12 or the second electrode 4
A plasma discharge channel is provided instead of one of the two electrodes. Note that the first substrate and the second substrate may be switched depending on the electrode configuration and the driving method to be applied. The plasma address type liquid crystal display device is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-128265.

The operation of the liquid crystal display device 100 according to this embodiment will be described with reference to FIGS.

When no voltage is applied to the liquid crystal region 30a, as shown in FIG.
Are aligned perpendicular to the substrate surfaces by the alignment regulating forces of the vertical alignment films 18 and 48 formed on the liquid crystal layer side of the substrates 100a and 100b. When this state is observed with a crossed Nicols state polarizing microscope, a dark field is obtained as shown in FIG. 2B (normally black state).

When a halftone display voltage is applied to the liquid crystal region 30a, a force acts on the liquid crystal molecules 33 having negative dielectric anisotropy to orient the major axis of the molecules perpendicular to the direction of the electric field. As shown in FIG. 2 (C), the substrate is inclined from a direction perpendicular to the substrate surface (halftone display state). At this time, due to the action of the polymer wall 16, the liquid crystal molecules 33 in the liquid crystal region 30a are axially symmetrically aligned around the central axis 35 shown by the broken line in the figure. When this state is observed with a polarizing microscope in a crossed Nicols state, an extinction pattern is observed in a direction along the polarization axis, as shown in FIG.

In the present specification, the term “axially symmetric orientation” includes concentric (tangential) and radial shapes. Further, for example, a spiral orientation shown in FIG. 3 is also included. This spiral alignment can be obtained by adding a chiral agent to the liquid crystal material to give a twist alignment force. Liquid crystal area 30a
In the upper part 30T and the lower part 30B, the liquid crystal layer is spirally oriented as shown in FIG. 3C, concentrically oriented near the center 30M, and twist-oriented in the thickness direction of the liquid crystal layer. . The central axis of the axisymmetric orientation generally coincides substantially with the normal direction of the substrate.

When the liquid crystal molecules are axially symmetrically aligned,
The viewing angle characteristics can be improved. When the liquid crystal molecules are axially symmetrically aligned, the refractive index anisotropy of the liquid crystal molecules is averaged in all azimuthal directions, so that the viewing angle characteristic seen in the halftone display state of the conventional TN mode liquid crystal display device is azimuthal. There is no problem that the angle differs greatly depending on the angular direction. Also,
If a horizontal alignment film and a liquid crystal material having a positive dielectric anisotropy are used, an axially symmetric alignment can be obtained even when no voltage is applied. At least a wide viewing angle characteristic can be obtained if the structure is configured to be axially symmetrical with a voltage applied.

The polymer walls 16 and 16a of the liquid crystal display device of this embodiment and the spacer beads 2
The states of 0 and 20a will be described with reference to FIG.

For the sake of simplicity, FIG.
The transparent electrode made of ITO and the vertical alignment film are not shown.
The thickness (cell gap) of the liquid crystal layer 30 is defined by the sum of the height of the top of the polymer wall 16 and the diameter of the spacer beads existing on the top. The spacer beads 20b located in the picture element region where the polymer wall does not exist are moved on the inclined surface 16a of the polymer wall 16 by a method described later.

If the length L of the inclined surface 16a shown in the figure is larger than the diameter D of the spacer beads 20, the inclined surface 16a
The spacer beads 20a that have moved onto the pixel regions 30a
Thus, the problem of the reduction in contrast due to the existence of the spacer beads 20b in the picture element region 30a and the deterioration of the viewing angle characteristics due to the disturbance of the axially symmetric orientation can be solved. The spacer beads 20 moved out of the picture element region 30a form an axially symmetric alignment fixed layer (usually,
It is fixed by a cured layer of a curable resin injected between the substrates after being mixed with the liquid crystal material, and is prevented from moving into the picture element region again.

The method for manufacturing the liquid crystal display device 100 of the present embodiment will be specifically described below.

The first substrate 100a was manufactured as follows. An ITO film was formed on a first transparent substrate 10 such as a glass substrate, and was patterned to form a first transparent electrode 12 having a thickness of about 200 nm. Next, the first transparent electrode 12
On the whole, an acrylic negative photosensitive resin having a thickness of about 1.2 μm (for example, C
T) by a spin coater, and at about 130 ° C., about 12
Prebaking was performed for 0 seconds. Further, proximity exposure was performed with ultraviolet light using a photomask having a predetermined polymer wall pattern, and development was performed. Developing was performed for about 60 seconds using a CD made by Fuji Film Ohlin Co., Ltd. as a developing solution. After washing and drying, post-baking was performed at 230 ° C. for 1 hour.

Through the above steps, the polymer wall 16 (having a height of about 1.0 μm and a tilt angle of about 12 μm) substantially surrounding the liquid crystal region 30a on the first transparent °, the length of the inclined surface is about 5.5 µm).
The length of the inclined surface 16a on the side surface of the polymer wall 16 can be adjusted by adjusting the distance (proxy gap) between the mask and the substrate surface at the time of proximity exposure and optimizing the pre-bake temperature after material application. The polymer wall 16 is formed so as to be longer than the diameter of 20. (In this embodiment, spacer beads having a diameter of 5.0 μm are used.) Thereafter, JALS-204 is further formed on the first transparent substrate 10 on which the first transparent electrode 12 and the polymer wall 16 are formed.
(Manufactured by JSR) was spin-coated to form a vertical alignment film.

On the other hand, as the second substrate 100b, an ITO film is formed on a second transparent substrate 40 such as a glass substrate, and is patterned to form a second transparent electrode 42 having a thickness of 200 nm. JALS-204 (made by JSR) on top
Was formed by spin coating to form a vertical alignment film 48.

The first substrate 10 manufactured as described above
0a and the second substrate 100b were joined via a spacer piece 20 having a diameter of 5.0 μm. The spacer beads 20 were uniformly dispersed on the entire surface of the first substrate 100a. The gap between the first substrate 100a and the second substrate 100b is the first substrate 1
The height is defined by the sum of the height of the polymer wall 16 provided at 00 a and the diameter of the spacer beads 20 scattered on the polymer wall 16. In this embodiment, the cell gap is set to about 6 μm. An n-type liquid crystal material (△ ε = −4.0, △) is provided between the joined first substrate 100a and second substrate 100b.
n = 0.08, a cell gap of 6 μm and a chiral agent added so as to form a 90 ° twist) to form a liquid crystal cell. In a liquid crystal material, 0.3% by weight of a compound A represented by the following (Chemical Formula 1) was
0.1% by weight of ur651 is mixed.

[0059]

Embedded image

(In the formula, n and n ′ represent 0 or an integer of 1 or more.) After injecting a mixture of a liquid crystal material and a photocurable resin, FIG.
As shown in (b), the liquid crystal cell was set up in the same direction as when actually used, and the liquid crystal cell was heated to 100 ° C., which is 80 ° C. or higher, which is the phase transition point of the liquid crystal material of this example. Since the liquid crystal material is heated to a temperature equal to or higher than the phase transition point, the viscosity of the liquid crystal material decreases, and the spacer beads 20b existing in the picture element without contributing to the definition of the cell gap move downward by gravity. At this time, vibration by ultrasonic waves (20 K to 1 MHz)
), The spacer beads 2 can be more efficiently
0b can be moved downward. The spacer beads 20b are caught by the inclined surface 16a of the polymer wall 16 formed for each picture element and do not move downward any further. By the above-described steps, the spacer beads 20b located in the picture element can be moved out of the picture element. further,
By forming a fixing layer for fixing an axially symmetric orientation described later, the spacer beads 20a are prevented from moving again, and the reliability is improved.

The liquid crystal display device 100 of the present embodiment
It is preferable that the liquid crystal molecules are axially symmetrically aligned with respect to one central axis for each liquid crystal region 30a. In order to form one central axis for each liquid crystal region 30a, it is preferable to perform the following axisymmetric alignment operation.

When the liquid crystal material is simply injected, a plurality of central axes may be formed in the liquid crystal region 30a when a voltage is applied, and a plurality of axially symmetric alignment tilt regions may be formed. Liquid crystal area 30
When a plurality of central axes are formed in a, the voltage-transmittance curve shown in FIG. 5 shows different transmittances for the same voltage when the voltage is increased and when the voltage is decreased (hysteresis). Is shown). When a voltage is applied to the liquid crystal cell in which only the liquid crystal material has been injected and the applied voltage is gradually increased, a plurality of central axes are formed first, and the Vth (threshold voltage: voltage at which the relative transmittance gives 10%) is applied. When the voltage of more than half is continuously applied, the central axis 35 which exists plurally
Becomes one for each liquid crystal region 30 a defined by the polymer wall 16. Therefore, it is preferable to perform an axially symmetric alignment operation in which a voltage of half or more of Vth is applied.

As described above with reference to FIG. 5, it is preferable that the liquid crystal display device of the present invention always apply a voltage of half or more of Vth. When a voltage is applied to the liquid crystal molecules aligned perpendicular to the substrate, the direction in which the liquid crystal molecules fall cannot be uniquely determined. As a result, a phenomenon in which a plurality of central axes are formed transiently occurs. When the voltage is continuously applied, a single central axis is formed in the liquid crystal region defined by the polymer wall, and this state is stable as long as a voltage of 1/2 Vt or more is applied.

1/2 Vt for stabilizing the axially symmetric orientation
By curing the photocurable resin mixed in the liquid crystal material in advance with a voltage of h or more applied, the axially symmetric alignment can be stabilized. After the photocurable resin is cured, even if the voltage of 1/2 Vth or more is removed, a plurality of central axes are not formed, and an axially symmetric orientation is formed with good reproducibility.

The addition amount of the photocurable resin varies depending on the material and varies depending on the material, and is not particularly limited in the present invention.
Preferably, it is 5%. If less than about 0.1%,
The axisymmetric alignment state cannot be stabilized by the cured resin, and the effect of fixing the position of the spacer beads is reduced. If it exceeds about 5%, the effect of the vertical alignment film is impaired, and the liquid crystal molecules deviate from the vertical alignment, so that the transmittance at the time of turning off the voltage increases (light leakage) and the black state at the time of turning off the voltage deteriorates.

In this embodiment, a voltage of 5 V is applied to form liquid crystal molecules in an axially symmetric orientation. The axisymmetric orientation region is
It was formed in the liquid crystal region 30a substantially surrounded by the polymer wall 16, and the central axis was formed at the center of the picture element. Thereafter, while applying a voltage 0.5 V higher than the threshold voltage 2.0 V, ultraviolet irradiation (365) is performed at room temperature (25 ° C.) for 10 minutes.
(intensity in nm: 16 mW / cm ² ) to cure the photocurable resin in the mixture. As a result, an axially symmetric alignment fixed layer was formed so as to cover the vertical alignment films of both substrates. The spacer beads were also fixed by the fixed layer, and did not move. Therefore, the spacer beads are not present in the picture element, and a liquid crystal display device having a good display quality without lowering the contrast or deteriorating the viewing angle characteristics is obtained.

[0067]

As described above, according to the present invention, a spacer bead can be used for defining the cell thickness in a liquid crystal display device in which the viewing angle characteristics are improved by utilizing the axially symmetric alignment of liquid crystal molecules. Therefore, a liquid crystal display device that achieves a reduction in manufacturing cost and an improvement in manufacturing yield is provided.
In addition, a liquid crystal display device having excellent display quality without lowering contrast or deteriorating viewing angle characteristics is provided because of a structure in which spacer beads do not exist in an axially symmetric liquid crystal region.

According to the second aspect of the present invention, the shape of the polymer wall required for moving the spacer beads existing in the liquid crystal region (picture element) out of the liquid crystal region is defined.

Further, according to the third aspect of the present invention, there is provided a liquid crystal display device fixed at the position so that the spacer beads moved outside the picture element do not move again.

According to the fourth aspect, a liquid crystal display device in which the spacer beads do not move under the influence of gravity can be obtained.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device in which the viewing angle characteristics are improved by utilizing the axially symmetric alignment of liquid crystal molecules. Thus, there is provided a manufacturing method for defining a cell gap using spacer beads of a lower cost and a simple process without forming a cell gap spacer. According to the present invention, there is also provided a method of manufacturing a liquid crystal display device in which display quality is not deteriorated due to the absence of spacer beads in a picture element.

According to the sixth aspect, there is provided a method for moving a spacer bead out of a picture element.

According to claim 7, another method for moving the spacer beads out of the picture element is provided.

According to the eighth aspect, there is disclosed a technique for fixing a spacer bead moved outside a picture element at that position, and the reliability is excellent in that the bead does not move even when displayed for a long time. A method for manufacturing a liquid crystal display device is provided.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a structure of a liquid crystal display device according to the present invention.

FIG. 2 is a schematic diagram illustrating an operation of a liquid crystal display device in an ASM mode. (A) and (b), when no voltage is applied, (c)
And (d) show the time of voltage application.

FIG. 3 is a schematic diagram illustrating an axially symmetric alignment state of liquid crystal molecules in a liquid crystal region.

FIG. 4 is a diagram for explaining the operation of the present invention and a manufacturing method.

FIG. 5 is a graph schematically showing a voltage-transmittance characteristic of the liquid crystal display device of the present invention.

FIG. 6 is a diagram schematically showing the result of observing the liquid crystal cell of Embodiment 1 with a polarizing microscope (crossed Nicols).

FIG. 7 is a diagram showing a method for manufacturing a conventional ASM mode liquid crystal display device.

FIG. 8 is a sectional view of a conventional color filter substrate.

[Explanation of symbols]

 10, 40 Glass substrate 12, 42 Transparent electrode 16 Polymer wall 16a Inclined surface of polymer wall 18, 48 Vertical alignment film 20 Spacer bead 20a Spacer bead 20b located on inclined surface of polymer wall 20b Positioned in picture element region Spacer bead 30 liquid crystal layer 30a liquid crystal region 33 liquid crystal molecule 35 symmetry axis (center axis) 100 liquid crystal display device 100a first substrate 100b second substrate

Continued on front page F term (reference) 2H089 HA03 JA03 KA03 LA07 LA09 LA16 LA17 LA20 NA09 NA12 NA15 QA12 QA16 TA04 2H090 HB08Y LA02 MA01 MA06 MA10 MA15 MA17 5C094 AA12 AA43 AA44 BA43 CA19 EC03 GB01

Claims (8)

[Claims] A first substrate, a second substrate disposed opposite to the first substrate, and a liquid crystal layer disposed between the first and second substrates. Having a polymer wall having a surface inclined with respect to the surface of the substrate on the first substrate, the liquid crystal layer having a plurality of liquid crystal regions divided by the polymer wall, Spacer beads defining the gap between the liquid crystal layers are present on the top of the polymer wall and on the inclined surface of one of the four sides of the polymer wall surrounding the liquid crystal tilt region. A liquid crystal display device characterized by the above-mentioned. 2. The liquid crystal display device according to claim 1, wherein a length of the inclined surface of the polymer wall is larger than a diameter of the spacer bead. 3. The liquid crystal according to claim 1, wherein the movement of the spacer beads is regulated by a curable resin for fixing the alignment of the liquid crystal molecules that are axially symmetrically aligned. Display device. 4. The liquid crystal according to claim 1, wherein the liquid crystal region is used so as to be substantially vertical so that the inclined surface of the polymer wall on which the spacer beads of the liquid crystal region are present is located below the vertical direction. Display device. 5. A semiconductor device comprising: a first substrate; a second substrate disposed to face the first substrate; and a liquid crystal layer disposed between the first and second substrates. A method for manufacturing a liquid crystal display device, wherein the liquid crystal layer has a plurality of liquid crystal regions divided by a polymer wall having a surface inclined with respect to the surface of the substrate; Forming a molecular wall, and thereafter, after dispersing spacer beads on the first substrate on which the polymer wall is formed, bonding a second substrate on the first substrate; A liquid crystal display device comprising: a step of injecting a liquid crystal material between first and second substrates; and a step of moving spacer beads dispersed in the liquid crystal region onto an inclined surface of the polymer wall. Manufacturing method. 6. The step of moving the spacer beads dispersed in the liquid crystal region onto the inclined surface of the polymer wall,
6. The method according to claim 5, wherein a liquid crystal cell obtained by injecting a liquid crystal material between the first and second substrates is set substantially vertically and a vibration is applied to the liquid crystal cell. 7. The step of moving the spacer beads dispersed in the liquid crystal region onto the inclined surface of the polymer wall,
6. The method for manufacturing a liquid crystal display device according to claim 5, wherein the method is performed by setting a liquid crystal cell obtained by injecting a liquid crystal material between the first and second substrates to be substantially vertical and heating the cell. 8. The method according to claim 8, further comprising, after the step of moving the spacer beads dispersed in the liquid crystal region on the inclined surface of the polymer wall, the step of mixing the liquid crystal material and polymerizing the injected curable resin. A method for manufacturing a liquid crystal display device according to any one of claims 5 to 7.