JPH0895057A - Liquid crystal display panel and manufacture thereof - Google Patents

Abstract

PURPOSE: To provide a liquid crystal display panel in which a twisting angle is increased for lowering driving voltage and an excellent visual property is provided. CONSTITUTION: Each picture element 19 is provided with a high pretilting angle area 12, in which a pretilting angle of a liquid crystal molecule 18a is 8 deg., and a low pretilting angle area 11, in which a pretilting angle of the liquid crystal molecule 18a is 1 deg.. In the inside of the picture element 19, the low pretilting angle area 11 is positioned in the center comparatively far from a bus-line 13. A visual characteristic based on the picture element 19 exhibits both a visual characteristic based on the high pretilt angle area 12 and a visual characteristic based on the low pretilt angle area 11 superposed with each other.

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 panel,
In particular, it relates to a TN (Twist Nematic) type liquid crystal display panel.

A liquid crystal display panel controls an electric potential of each pixel by an active element, and each pixel has an alignment film which is normally subjected to an alignment treatment, which is disposed above and below the liquid crystal, and which encapsulates the liquid crystal together with the alignment film. An electrode for applying a voltage to the liquid crystal is provided outside the member.

An active liquid crystal display panel is a CRT (Cat
Since it has a display characteristic similar to that of a hode ray tube) and has low power consumption, it is often used especially for portable electronic devices such as laptop computers. Since portable electronic devices are often used with batteries,
It is required to suppress the power consumption as much as possible in order to extend the usage time, and studies for reducing the driving voltage of the liquid crystal display panel are being actively conducted.

[0004]

2. Description of the Related Art The following method can be considered to reduce the driving voltage of a TN type liquid crystal display panel.

(1) Widen the twist angle of the liquid crystal.

(2) The amount of chiral material mixed in the liquid crystal is reduced.

A conventional example in which the drive voltage of the liquid crystal display panel is reduced by the method (1) is disclosed below (Japanese Patent Laid-Open No. Sho 61-61).
-105527) will be briefly described.

As described above, each pixel used in the liquid crystal display panel has a structure in which liquid crystal is vertically sandwiched between alignment films. The twist angle referred to in the method (1) refers to the angle formed by the alignment direction when the alignment film on the upper surface is subjected to the alignment treatment and the alignment direction of the alignment processing on the alignment film on the lower surface. . Figure 11 shows the definition of twist angle.
Shown in (a) and (b). The conventional invention is shown in FIG.
The feature is that the twist angle of 90 ° shown in (a) is expanded to 100 ° shown in FIG. 11 (b).

Reference numeral 1a is an alignment film provided on the upper surface, and 1b
Indicates an alignment film disposed on the lower surface. The alignment direction of the alignment film 1a is indicated by 2a. The orientation direction of the orientation film 1b is indicated by 2b.

Next, FIG. 12 compares changes in transmittance with respect to voltage in liquid crystal display panels having different twist angles.

In FIG. 12, a curved line 3 shown by a broken line shows the transmittance with respect to the voltage of a general liquid crystal display panel having a twist angle of 90 °. Curve 4 shown by a solid line shows transmittance light with respect to the voltage of the liquid crystal display panel having a twist angle of 100 ° larger than 90 ° (shown in FIG. 12B).

As can be seen from FIG. 12, the liquid crystal display panel having a twist angle of 100 ° shown by the curve 4 has a threshold voltage for turning on the liquid crystal display panel more than the liquid crystal display panel having a twist angle of 90 ° shown by the curve 3. Is low. From this, it is understood that the liquid crystal display panel having a larger twist angle value of 100 ° can operate at a lower voltage than the liquid crystal display panel having a smaller twist angle value of 90 °.

However, in the liquid crystal display panel, a phenomenon of display reversal in which the transmittance once decreased in the reversal visual direction rises again can be seen. (FIG. 13, curves 5 and 6) It is also clear that this phenomenon appears more markedly in the curve 6 showing the characteristics of the liquid crystal display panel having a larger twist angle. This phenomenon causes a decrease in the ON / OFF contrast of the liquid crystal display panel and a deterioration in the visual characteristics of the liquid crystal display panel.

In the conventional example, this problem is solved by dividing the pixel into two,
This is solved by the alignment division method in which the pretilt angles of the divided pixels rise from different directions.

A method of lowering the driving voltage of the liquid crystal display panel by the method of reducing the mixing amount of the chiral material described in (2) will be described.

The chiral material is a liquid crystal compound (for example, cholesteric liquid crystal) added to the liquid crystal material of the liquid crystal display panel, and is used for the purpose of controlling the chiral pitch which is an index of the twist strength of the liquid crystal molecules. is there.

By reducing the addition amount of the chiral material, the chiral pitch becomes longer and the twist of the liquid crystal molecules is easily released at a low voltage, so that the liquid crystal display panel can be driven at a lower voltage.

[0018]

However, in the alignment division method, there is a linear region where light leaks at the boundary line of regions having different pretilt angles, which is called a declination line, even though the liquid crystal display panel is in the OFF state. appear. There is a method to prevent the deterioration of the characteristics of the liquid crystal display panel by providing a light-shielding pattern in the area where the declination line is generated, but this method reduces the aperture ratio of the liquid crystal panel due to the light-shielding pattern, so the light utilization rate of the liquid crystal display panel is reduced. Will decrease and it will be necessary to make the backlight stronger, which is contrary to the intention to reduce the power consumption of the liquid crystal display panel.

Further, when the chiral pitch is lengthened by decreasing the amount of the chiral material added, the force that defines the twist of the liquid crystal molecules becomes weak, and a reverse twist region that twists in the direction opposite to the predetermined direction tends to occur. . The reverse twist region appears as display unevenness on the liquid crystal display panel and thus deteriorates the characteristics of the liquid crystal display panel.

In view of the above points, it is an object of the present invention to provide a liquid crystal display panel which can be driven at a low voltage and is excellent in characteristics such as visual characteristics and a manufacturing method thereof.

[0021]

In order to solve the above problems, the present invention has the following configuration.

In the liquid crystal display panel according to the invention of claim 1, a pair of transparent substrates arranged to face each other, electrodes respectively provided on the pair of transparent substrates, and electrodes formed respectively on the electrodes are opposed to each other as a pair. The alignment film, the liquid crystal sealed between the pair of alignment films, and the pair of transparent substrates are bonded to the surface that is the back surface with respect to the surface that seals the liquid crystal.
In a liquid crystal display panel having a large number of pixels made up of a pair of polarizing plates of 0 °, a plurality of regions having different pretilt angles of liquid crystal molecules of each pixel are provided.

A liquid crystal display panel according to a second aspect of the invention is characterized in that the twist angle of liquid crystal molecules of the liquid crystal has a value of 90 ° or more and less than 110 °.

In the liquid crystal display panel according to a third aspect of the present invention, the plurality of regions are composed of a high pretilt angle region of liquid crystal molecules, a high pretilt angle region, and a low pretilt angle region of liquid crystal molecules, and a low pretilt angle region. In the pretilt angle region and the low pretilt angle region, the low pretilt angle region is arranged further away from the bus line to be the wiring, and the high pretilt angle region is provided closer to the bus line. To do.

A liquid crystal display panel according to a fourth aspect of the present invention is characterized in that a liquid crystal is added with a chiral material whose chiral pitch becomes shorter as the temperature rises.

In the liquid crystal display panel according to the present invention, a pair of transparent substrates are arranged so as to face each other, electrodes are respectively provided on the pair of transparent substrates, and then an alignment film is formed on each of the electrodes. Manufacture of a liquid crystal display panel in which liquid crystal is sealed between alignment films, and a pair of transparent substrates is bonded with a polarizing plate having a crossing angle of 90 ° of polarization axes on the surface that is the back surface with respect to the surface that seals the liquid crystal. The method is characterized in that a high pretilt angle region and a low pretilt angle region, which are regions having different pretilt angles, are provided by changing the rubbing treatment applied to the alignment film.

According to a sixth aspect of the liquid crystal display panel of the present invention, a pair of transparent substrates are arranged so as to face each other, electrodes are respectively provided on the pair of transparent substrates, and then an alignment film is formed on each of the electrodes. Manufacture of a liquid crystal display panel in which liquid crystal is sealed between alignment films, and a pair of transparent substrates is bonded with a polarizing plate having a crossing angle of 90 ° of polarization axes on the surface that is the back surface with respect to the surface that seals the liquid crystal. The method is characterized in that a high pretilt angle region and a low pretilt angle region, which are regions having different pretilt angles, are provided by forming the alignment film with different alignment film materials.

In a liquid crystal display panel according to a seventh aspect of the present invention, a pair of transparent substrates are disposed so as to face each other, electrodes are respectively provided on the pair of transparent substrates, and then an alignment film is formed on each of the electrodes to form a pair of transparent substrates. Manufacture of a liquid crystal display panel in which liquid crystal is sealed between alignment films, and a pair of transparent substrates is bonded with a polarizing plate having a crossing angle of 90 ° of polarization axes on the surface that is the back surface with respect to the surface that seals the liquid crystal. The method is characterized in that a high pretilt angle region and a low pretilt angle region, which are regions having different pretilt angles by irradiating the predetermined region on the alignment film with ultraviolet light, are provided. .

[0029]

According to the invention described in claim 1, the plurality of regions having different pretilt angles of the liquid crystal molecules are provided in each pixel, so that the visual characteristics of the regions having different pretilt angles are superimposed. As a result, the visual characteristics of the liquid crystal display panel are configured, and the variation in the transmittance that occurs in the display inversion direction can be suppressed.

Further, since the directions of the pretilt angles of the liquid crystal molecules are the same in the pixel, the declination line does not occur. Therefore, it is not necessary to provide a light-shielding pattern on the domain boundary, and the aperture ratio of the liquid crystal display panel is not reduced, so that it is not necessary to strengthen the backlight, and it is possible to suppress an increase in power consumption of the liquid crystal display panel.

According to the second aspect of the invention, the drive voltage of the liquid crystal display panel is reduced by adopting a structure in which the twist angle of the crystal molecules of the crystal has a value of 90 ° or more and less than 110 °.

According to the third aspect of the present invention, the high pretilt angle region is provided in the vicinity of the bus line serving as the wiring, whereby the liquid crystal molecules in the low pretilt angle region are applied to the bus line or the current flowing through the bus line. Also, it is not affected by the magnetic field generated by them.

In the invention according to claim 4, by adding a chiral material whose chiral pitch is shortened as the temperature rises to the liquid crystal, the easiness of unwinding of the liquid crystal molecules at the time of driving the liquid crystal display panel is at room temperature. Follow the chiral pitch,
Since the strength that regulates the twist of liquid crystal molecules is determined by the chiral pitch at the cooling temperature after annealing, which is a higher temperature, a liquid crystal display panel that has a low driving voltage and does not have a reverse twist region is used. realizable.

According to the fifth aspect of the present invention, by providing the regions having different pretilt angles by changing the rubbing process applied to the alignment film, the high pretilt angle region and the low pretilt angle region can be provided by a simple process.

According to the sixth aspect of the present invention, by forming the alignment film from different alignment film materials, the high pretilt angle region and the low pretilt angle region can be provided by one rubbing treatment.

According to the seventh aspect of the invention, the high-pretilt angle region and the low-pretilt angle region can be provided by forming the alignment film from different alignment film materials in one rubbing process and without performing the etching process. it can.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the first embodiment corresponding to claims 1 to 5 will be described below. FIG. 1 and FIG. 2 are schematic structure diagrams of a liquid crystal display panel of the first embodiment. 1 is a top view, FIG.
FIG. 2 is a sectional view taken along the line segment AA ′ in FIG. 1.

First, the top view and FIG. 1 will be described.

The liquid crystal display panel 10 constructed in the present embodiment is a 10.4 inch diagonal TFT liquid crystal display composed of 640 × 480 pixels 19.

Each pixel 19 has a low pretilt angle region 11 and a high pretilt angle region 12, which are regions having the same orientation direction but different pretilt angles, and the low pretilt angle region 11
Is shown as a region surrounded by a broken line in the figure. The low pretilt angle region 11 is located at the center of the high pretilt angle region 12 and is arranged so as to be surrounded by the high pretilt angle region 12. Due to this arrangement, the low pretilt angle region 11 is arranged at a position relatively distant from the bus line 13 which is the wiring of the liquid crystal display panel, and the structure is less susceptible to the influence of current, voltage or magnetic field.

Next, FIG. 2 which is a sectional view taken along the line segment AA '
The configuration of the liquid crystal display panel 10 will be described using. The first transparent substrate 15a and the second transparent substrate 15b are arranged to face each other with an interval of 5 μm, and the liquid crystal 18 is sealed between them. First transparent substrate 15a and second transparent substrate 1
Alignment films 17a and 17b are interposed between the surface of the liquid crystal 18 where 5b seals the liquid crystal 18 and the alignment films 17a and 1b.
7b and the transparent substrates 15a and 15b are respectively provided with a liquid crystal 18
A counter electrode 16a for applying a voltage to the pixel electrode 16b and a pixel electrode 16b are provided.

The twist angle is 10 for the purpose of low voltage driving.
It was set to 0 °. Further, the liquid crystal 18 is added with a chiral material whose chiral pitch becomes shorter as the temperature rises.

The pretilt angle is provided with regions having different values by changing the treatments and materials of the alignment films 17a and 17b.

For convenience of description, the pretilt angle will be described before describing the characteristics of the liquid crystal display panel 10 of the first embodiment.

FIG. 3 is a schematic diagram for explaining the definition of the pretilt angle.

The pretilt angle means the alignment film 17a (or 1
7b) the orientation direction A by the rubbing treatment applied on the above,
The angle formed by the direction of the orientation vector B of the liquid crystal molecules 18a is an important factor that determines the visual characteristics, the voltage characteristics, and the orientation characteristics.

In the present embodiment, the pretilt angle in the high pretilt angle region is 8 °, the pretilt angle in the low pretilt angle region is 1 °, which has a difference of 7 ° and has the same orientation direction A.

FIG. 4 shows T (transmittance) -V (applied voltage) representing the inverted visual direction 40 ° of the liquid crystal display panel 10 of this embodiment.
A curve 20 is shown. For comparison, TV curves 21 and 22 showing the visual characteristics of the conventional liquid crystal display panel in which the magnitude of the pretilt angle is uniform over the entire area of the pixel are also shown.

The drive voltage was evaluated by the voltage Vsat at which a contrast of 100 is obtained in normally white display. The characteristics of the conventional liquid crystal display panel are that the TV curve 21 has a pretilt angle of 1 °, which is the same as the low pretilt angle of the liquid crystal display panel 10, and the TV curve 22 is 8 °, which is the same as the high pretilt angle of the liquid crystal display panel 10. . Further, both twist angles are 100 °, which is the same value as that of the liquid crystal display panel 10.

When there are two regions having high and low pretilt angles in the pixel 19, the human eye can see the TV of two liquid crystal display panels having the pretilt angles of each region.
The curves 21 and 22 are recognized as the overlapping TV curve 20.

Therefore, as shown in FIG.
Has an intermediate value between the T-V curves 21 and 22 when each value of voltage is applied.

Here, regarding the TV curve 21 of the liquid crystal display panel having the pretilt angle of 1 ° and the TV curve 22 of the liquid crystal display panel having the pretilt angle of 8 °, the display is inverted (convex upward in FIG. 4). The voltage that gives a bump-like shape is deviated, and the TV curve 21 exhibits a downwardly convex profile in the inversion region. When the voltage is applied, the TV curve 22 exhibits an upwardly convex profile. Conversely, when the voltage is applied, the T-V curve 22 shows a downward convex profile in the inversion region.
The −V curve 21 shows a convex profile.

Therefore, the above-mentioned T-V curve 20 is T-
The display inversion phenomenon in which the transmittance increases in the inversion region seen in the V curves 21 and 22 is canceled.

Further, the declination line which occurs when the pretilt angle direction of the liquid crystal molecules 18a is changed is also a problem because the direction is uniform only by changing the size of the pretilt angle in this embodiment. I won't. Therefore, the reduction of the aperture ratio and the reduction of the light utilization efficiency due to the light-shielding pattern provided as a countermeasure for the discrimination line do not occur, so that a liquid crystal display panel having a higher aperture ratio than the conventional one can be obtained.

Further, in the evaluation of Vsat, the conventional Vsat = 3.
It was improved from 5V to Vsat = 2.8V.

Next, the effect of using a chiral material whose chiral pitch becomes shorter as the temperature rises will be described.

S-811 which has been conventionally used as a chiral material in a conventional liquid crystal display panel having a uniform pretilt angle over the entire area of pixels prepared for comparison.
(Manufactured by Merck) is added to the liquid crystal, 90 ° C. after injection of the liquid crystal,
Annealing was performed under the condition of 10 minutes.

The liquid crystal cooled to room temperature after annealing had a chiral pitch of 80 μm, and display unevenness due to the reverse twist region occurred on the entire surface of the completed conventional liquid crystal display panel.

On the other hand, the chiral material used in this example has a chiral pitch of 80 μm at room temperature, but the chiral pitch at 75 ° C., which is the liquid crystal material NI point (the temperature at which the liquid crystal transitions to liquid), is as short as 50 μm. It has a value. In this embodiment, there was no occurrence of display unevenness due to the occurrence of the reverse twist area.

The present invention is not limited to the above embodiment, and it is possible to provide a plurality of regions having different pretilt angles in one pixel. For example, one pixel includes a region having a large pretilt angle, a region having a small pretilt angle, and a region having a size of the pretilt angle between them.

Next, a method for manufacturing the liquid crystal display panel 10 of this embodiment will be described with reference to FIGS. 5 and 6A to 6K. FIG. 5 illustrates each manufacturing process of the liquid crystal display panel 10, and FIGS. 6A to 6K illustrate the manufacturing process of the liquid crystal display panel 10 step by step.

In steps 101 and 107 in FIG. 5, first, transparent substrates 15a and 15b are prepared. As shown in FIG. 6A, the counter electrode 16a is provided on the first substrate 15a. Further, as shown in FIGS. 6F and 6G, the pixel electrode 16b is provided on the second transparent substrate 15b.

Next, as shown in steps 102 and 108 in FIG. 5, the alignment film 1 is formed on the counter electrode 16a and the pixel electrode 16b.
7a and 17b are provided.

This state is shown in FIGS. 6 (c) and 6 (h).

Next, in FIG. 5, steps 103, 104 and 10 are performed.
Alignment films 17a and 17 as described as 9, 110
The area I on b is masked and the area II is subjected to orientation treatment. This step is shown in FIGS. 6 (d) and (i). FIG. 6D shows a photolithography process for a region indicated by I in the figure, which is a low pretilt angle region for separately forming the high pretilt angle region 12 and the low pretilt angle region 11 on the first transparent substrate 15a. The resist 30a is patterned by using the masking.

Further, an alignment process is performed on the high pretilt angle region indicated by II from above the resist 30a. The region II is rubbed twice. By this rubbing treatment, the pretilt angle of the low pretilt angle region 11 held by the liquid crystal molecules of the liquid crystal display panel 10 is 8 °.

Further, FIG. 6I shows the second transparent substrate 15b.
11 illustrates the step of performing the same treatment for the alignment treatment of the region II.

Next, as shown by steps 106 and 112 in FIG. 5, patterning of the resist 30b is performed in the region II in the same manner as the resist 30a is provided. This step is as shown in FIGS.
The resist 30a is peeled off after the rubbing treatment of the region II, and the region II is covered with the resist 30b.

Next, as described in steps 106 and 112 of FIG. 5, both the first substrate 15a and the second substrate 15b are subjected to the alignment treatment to the region I.

As shown in (e) and (j) of FIG. 6, the resist 30b was used as a mask and the region I was rubbed 10 times to form a low pretilt angle region. By this processing, the pretilt angle of the liquid crystal molecules in the region I becomes 1 °. The resist 30b is peeled off after the orientation process of the region I is completed.

After the steps 106 and 112 in FIG. 5 are completed, as shown in step 113 in FIG. 5, the first transparent substrate 15a and the second transparent substrate 15b are made to face each other with the surfaces provided with the alignment films 17a and 17b facing each other. The liquid crystal 18 is injected between them.

Further, the polarizing films, which are the alignment films 14a and 14b, are adhered to the surface of the transparent substrates 15a and 15b, which are arranged to face each other in step 114 of FIG. The liquid crystal display panel 10 of k) is completed.

The manufacturing method of the liquid crystal display panel 10 of the first embodiment can be realized if there is equipment for exposure, and the liquid crystal display panel 10 can be manufactured by a relatively reliable process. The alignment film 17 is formed by another method.
7 and 8 (a) to 8 (k) regarding the third embodiment in which regions having different pretilt angles are provided on a and 17b.
Will be described with reference to.

FIG. 7 illustrates each manufacturing process of the liquid crystal display panel 10 according to the second embodiment. In addition, FIGS. 8A to 8K show the manufacturing steps of the liquid crystal display panel 40 according to the second embodiment in order and illustrated in each step. Also in steps 115 and 121 of FIG. 7, in manufacturing the liquid crystal display panel 40, first, the transparent substrate 15a,
Prepare 15b.

Next, the counter electrode 16a is formed on the first substrate 15a.
And the pixel electrode 1 on the second transparent substrate 15b.
6b is provided.

The process of performing this step on the first transparent substrate 15a is shown in FIGS. 8A and 8B, and the process of performing this step on the second substrate 15b is shown in FIGS. 8F and 8G.

Next, in FIG. 7, steps 116, 117 and 12 are performed.
Alignment films 17a17b are formed as indicated by 2,123,
Further, second alignment films 27a and 27b having different alignment materials are formed on the alignment films 17a and 17b.

This state is shown in FIGS. 8 (c) and 8 (h).

At this time, in this embodiment, the alignment film 17 is formed.
It is necessary that the alignment films 27a and 2b are made of an alignment material which gives liquid crystal molecules with a pretilt angle lower than those of a and 17b.

Next, masking for forming regions having different pretilt angles is performed as described in steps 118 and 124 in FIG.

This state is shown by (d) and (i) in FIG. High pretilt angle region 12 and low pretilt angle region 1
1 in the figure, which is a high tilt angle region for making 1 separately.
The region indicated by is masked by patterning the resist 30a using a photolithography process.

Next, as shown by 119 and 125 in FIG. 7, a high pretilt angle region and a low pretilt angle region are formed.

In this step, as shown in FIGS. 8 (e) and 8 (j), the alignment film 1 is formed by etching 27a and 27b.
Alignment films 27a and 27b are patterned on 7a and 17b. As a result, in the region I, the alignment films 27a and 27b made of the alignment material that give the liquid crystal molecules a higher pretilt angle.
Are in contact with the liquid crystal 18, and the alignment films 17a and 17b made of an alignment material that give a lower pretilt angle are in contact with the liquid crystal 18 in the region II to determine the pretilt angle of the liquid crystal molecules 15a after the liquid crystal 18 is sealed.

Next, as shown in steps 120 and 126 in FIG. 8, the regions I and II are aligned at one time.

In this embodiment, the conditions for this orientation treatment are a pressing amount of 0.3 mm and rubbing times of 5 times. As a result, the pretilt angle in the region I was 1.5 °, and the pretilt angle in the region II was 9 °.

After steps 120 and 126 are completed, as shown in step 127 of FIG. 7, the first transparent substrate 15a and the second transparent substrate 15b are made to face each other with the alignment films 17a, 17b, 27a and 27b provided. The liquid crystal 18 is enclosed between them.

Further, in the step 128 of FIG. 7, the transparent films 15a and 15b, which are arranged to face each other, are bonded to the surfaces of the transparent films 15a and 15b, which are the outer surfaces of the liquid crystal 18, and the alignment films 14a and 14b. The liquid crystal display panel 40 of k) is completed.

In this embodiment as well as in the first embodiment, the visual characteristics of the liquid crystal display panel 40 were evaluated by the TV curve in the display inversion direction of 40 °. As a result, Vsat = 2.8V, which is the same value as in the first embodiment, was obtained, and the display inversion did not occur.

In the method of manufacturing the liquid crystal display panel 40 of the second embodiment, the number of masking steps is small, and since the rubbing process can be performed at one time, it is possible to manufacture the liquid crystal display panel 40 with less man-hours.

Further, a third embodiment in which the high pretilt angle region and the low pretilt angle region are provided by another method will be described with reference to FIGS. 9 and 10A to 10G.

FIG. 9 is a diagram for explaining each manufacturing process of the liquid crystal display panel 50 according to the third embodiment.
(A) to (g) show the manufacturing steps of the liquid crystal display panel 50 according to the third embodiment in order and illustrated in each step.

As described in steps 129 and 133 in FIG. 9, in manufacturing the liquid crystal display panel 50 of the third embodiment, the first transparent substrate 15a and the second transparent substrate 1 are used.
The counter electrode 16a and the pixel electrode 16b are provided on 5b.

This state is shown in FIGS. 10 (a) and (b) or (d) and (e).

In manufacturing the liquid crystal display panel 50, the first transparent substrate 15a is prepared as shown in FIG.
In (d), the second transparent substrate 15b is prepared. Further, as shown in FIG. 10B, the counter electrode 16a is provided on the first substrate 15a, and the pixel electrode 16b is provided on the second transparent substrate 15b as shown in FIG. 10E.

Next, as described in step 130, step 131, step 134 and step 135 of FIG.
a, an alignment film is provided on the second transparent substrate 15b, and masking is performed in order to create regions having different pretilt angles.

This state is shown in FIGS. 10 (c) and 10 (f). In FIG. 3C, an alignment film alignment film 17a is formed on the first transparent substrate 15a, and a resist 30b for covering the region II is provided on the alignment film 17a by using a photolithography process. Only the region I on the alignment films 17a and 17b was changed by irradiating it with ultraviolet light.
This process is similarly performed on the second transparent substrate 15b and the alignment film 17b, and this state is shown in FIG.

After this, the resist 30b is peeled off to remove the region I.
And region II are oriented at once under the same conditions. As a result,
The pretilt angle of the region I is 2 °, the pretilt angle of the region II is 8 °, and the difference between the pretilt angles is 6 °.

After the steps 132 and 136 are completed, as shown in step 137 of FIG. 10, the first transparent substrate 15a and the second transparent substrate 15b are arranged with the surfaces provided with the alignment films 17a and 17b facing each other. The liquid crystal 18 is sealed between them.

Further, the alignment films as the alignment films 14a and 14b are adhered to the surfaces of the transparent substrates 15a and 15b facing each other in step 138 of FIG. The liquid crystal display panel 50 of g) is completed.

In this embodiment as well as in the first and second embodiments, the visual characteristics of the liquid crystal display panel 40 are displayed in the display inversion direction 40.
It was evaluated by a T-V curve of °. As a result, Vsat = 2.8V, which is the same value as in the first and second embodiments, was obtained, and the display inversion did not occur.

Since the method for manufacturing the liquid crystal display panel 50 of the third embodiment has a small number of masking steps and can perform Rabin processing at the same time and does not include an etching step, the number of man-hours required for the liquid crystal display can be reduced in the above-described embodiments. The display panel 50 can be created.

In each of the above embodiments, the twist angle is 100 °, but the same effect can be obtained in any case as long as it is in the range of 90 ° or more and less than 110 °.

[0103]

As described above, according to the first and second aspects of the present invention, it is possible to realize a liquid crystal display panel of low power consumption in which no disclination line is generated or a reverse twist region is not generated. Further, by superimposing the visual characteristics of different pretilt angles, the display inversion is substantially canceled even if the twist angle is increased, and a liquid crystal display panel having excellent visual characteristics is realized.

According to the third aspect of the present invention, the low pretilt angle region is not affected by the current flowing through the bus line, the magnetic field generated by the bus line, and the like, and display unevenness due to the occurrence of the reverse twist region can be prevented. It was

According to the invention described in claim 4, a liquid crystal display panel having a long chiral pitch at room temperature and a strong action for defining a twisting direction of liquid crystal molecules is realized, and low power consumption is achieved.
Moreover, it was possible to suppress the occurrence of the reverse twist region.

According to the invention described in claim 5, the high pretilt angle region and the low pretilt angle region can be provided in a simple process, and the reliability of the process can be improved.

According to the sixth aspect of the invention, the high pretilt angle region and the low pretilt angle region can be provided by one rubbing treatment, and the number of steps can be reduced.

According to the invention as set forth in claim 7, the high pretilt angle region and the low pretilt angle region can be provided by a single rubbing treatment without performing an etching treatment, and the number of steps can be further reduced.

[Brief description of drawings]

FIG. 1 is a top view showing a schematic configuration of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line segment A-A ′ in FIG.

FIG. 3 is a diagram illustrating a pretilt angle.

FIG. 4 is a diagram showing the TV characteristics of the first embodiment of the present invention in comparison with a conventional liquid crystal display panel.

FIG. 5 is a diagram illustrating a process of the first embodiment of the present invention.

FIG. 6 illustrates the process of FIG.

FIG. 7 is a diagram illustrating a process of the second embodiment of the present invention.

FIG. 8 illustrates the process of FIG.

FIG. 9 is a diagram illustrating a process of the third embodiment of the present invention.

FIG. 10 illustrates the process of FIG.

FIG. 11 is a diagram illustrating a twist angle.

FIG. 12 is a diagram showing a TV characteristic of a conventional liquid crystal display panel.

FIG. 13 is a diagram showing a TV characteristic in a reversed visual direction.

[Explanation of symbols]

 10, 40, 50 Liquid crystal display panel 11 High pretilt angle region 12 Low pretilt angle region 13 Bus line 14a, 14b Polarizing film 15a, 15b Transparent substrate 16a, 16b Electrode 17a, 17b, 27a, 27b Alignment film 18 Liquid crystal 19 Pixel 20 TV curve of the liquid crystal display panel of the invention

Claims (7)

[Claims] 1. A pair of transparent substrates arranged to face each other, electrodes provided on the pair of transparent substrates, alignment films respectively formed on the electrodes and facing each other, and the pair. A liquid crystal enclosed between the alignment films, and a pair of polarizing plates having a crossing angle of 90 ° of polarization axes adhered to the surface of the pair of transparent substrates, which is the back surface with respect to the surface for sealing the liquid crystal. In a liquid crystal display panel having a large number of pixels, the liquid crystal display panel is provided with a plurality of regions having different pretilt angles of liquid crystal molecules of the respective pixels and having the same alignment direction. 2. The twist angle of liquid crystal molecules of the liquid crystal is 90 °.
The liquid crystal display panel according to claim 1, wherein the liquid crystal display panel has a value of less than 110 °. 3. The plurality of regions are composed of a high pretilt angle region of the liquid crystal molecule, a high pretilt angle region and a low pretilt angle region of the liquid crystal molecule, and a low pretilt angle region, and the high pretilt angle region and the low pretilt angle region. 2. The low pretilt angle region is arranged at a position further away from the bus line to be the wiring, and the high pretilt angle region is provided closer to the bus line. 2. The liquid crystal display panel according to item 2. 4. The liquid crystal display panel according to claim 1, wherein a chiral material whose chiral pitch is shortened as the temperature rises is added to the liquid crystal. 5. A pair of transparent substrates are arranged so as to face each other, electrodes are respectively provided on the pair of transparent substrates, an alignment film is formed on each of the electrodes, and a liquid crystal is provided between the pair of alignment films. A method for manufacturing a liquid crystal display panel, comprising encapsulating and adhering a polarizing plate having a crossing angle of 90 ° of polarization axes to a surface which is a back surface with respect to a surface where the pair of transparent substrates seals the liquid crystal. A method for manufacturing a liquid crystal display panel, characterized in that a high pretilt angle region and a low pretilt angle region, which are regions having different pretilt angles, are provided by changing a rubbing treatment applied to a film. 6. A pair of transparent substrates are arranged so as to face each other, electrodes are provided on the pair of transparent substrates respectively, and then an alignment film is formed on each of the electrodes, and a liquid crystal is provided between the pair of alignment films. A method for manufacturing a liquid crystal display panel, comprising encapsulating and adhering a polarizing plate having a crossing angle of 90 ° of polarization axes to a surface which is a back surface with respect to a surface where the pair of transparent substrates seals the liquid crystal. A method of manufacturing a liquid crystal display panel, comprising providing a high pretilt angle region and a low pretilt angle region, which are regions having different pretilt angles, by forming the films with different alignment film materials. 7. A pair of transparent substrates are arranged so as to face each other, electrodes are respectively provided on the pair of transparent substrates, an alignment film is formed on each of the electrodes, and a liquid crystal is provided between the pair of alignment films. A method for manufacturing a liquid crystal display panel, comprising encapsulating and adhering a polarizing plate having a crossing angle of 90 ° of polarization axes to a surface which is a back surface with respect to a surface where the pair of transparent substrates seals the liquid crystal. A method of manufacturing a liquid crystal display panel, comprising: a high pretilt angle region and a low pretilt angle region, which are regions having different pretilt angles by irradiating ultraviolet light only on a predetermined region on the film.