JP2986310B2 - 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 liquid crystal display device capable of eliminating viewing angle dependence.

[0002]

2. Description of the Related Art A liquid crystal display (LCD) has a liquid crystal layer provided between a pair of substrates disposed opposite to each other, and changes the orientation of liquid crystal molecules in the liquid crystal layer to change the optical refractive index. Thus, the display is performed. In order to control the alignment of such liquid crystal molecules, a so-called twisted nematic (TN) type liquid crystal display device is mainly used. In this liquid crystal display device, liquid crystal molecules are preliminarily oriented so as to be substantially parallel to the substrate and twisted by about 90 °, and a voltage is applied to electrodes formed on two opposing substrates to apply a voltage perpendicular to the substrate. An electric field is generated in the direction, and the liquid crystal molecules are changed in the direction of the electric field by utilizing the dielectric anisotropy of the liquid crystal, thereby changing the orientation and causing a change in the optical refractive index.

FIG. 13 is a sectional view showing an example of a typical TN type liquid crystal display device. This liquid crystal display device has a liquid crystal layer 1
One (lower) substrate 131 has a transparent electrode 131c, an insulating protective film 131d, and an alignment film 131e on a base glass substrate 131a. They are formed in this order. The insulating protective film 131d has a window opening structure in which a part of a pixel is opened in order to prevent a DC component from being applied to the liquid crystal layer 133.

On the other substrate 132, a color filter 132b, a transparent electrode 132c, an insulating protective film (not shown) and an alignment film 132e are formed in this order on a glass substrate 132a as a base. This insulating protective film also has a window opening structure in which a part of the pixel is opened in order to prevent a DC component from being applied to the liquid crystal layer 133, similarly to the insulating protective film 131d.
This window opening structure portion is formed by the insulating protective film 131d described above.
And a window-opening structure portion, and pixels are formed at the facing portion.

[0005] The ends (not shown) of the substrates 131 and 132 are sealed with a resin or the like, and peripheral circuits for driving liquid crystal are mounted. A similar structure is adopted in an active matrix type liquid crystal display device in which a non-linear electric element is formed on at least one of the substrates and a liquid crystal is driven by the non-linear electric element.

In the TN type liquid crystal display device described above, the liquid crystal molecules 133a in the liquid crystal layer 133 are twisted by 90 ° between the substrate 131 and the substrate 132 when no voltage is applied to the transparent electrodes 131c and 132c. In addition, the liquid crystal molecules 133 are aligned with a pretilt angle of δ with respect to both substrates 131 and 132, and when a voltage is applied, the liquid crystal molecules 133 are aligned.
a stands up. The rising direction is predetermined in order to prevent the occurrence of discrimination due to multi-domain, and the direction is called an average vector of the alignment direction of the liquid crystal molecules.

[0007]

However, since the rising direction of the liquid crystal molecules is determined as described above,
When a person (observer) observes a liquid crystal display device to which a voltage is applied, a phenomenon occurs in which contrast changes depending on an angle at which the liquid crystal display device is viewed. Part 1
An example is described below.

FIG. 14 shows characteristics of an applied voltage [V] and a transmittance [T] in a normally white mode liquid crystal display device in which light is transmitted when no voltage is applied to obtain a white display. Here, in the liquid crystal display device of FIG.
With respect to the tilt of the liquid crystal molecules 133a, the θ1 side is defined as the normal viewing angle direction, and the θ2 side is defined as the reverse viewing angle direction.

When the display surface of the liquid crystal display device is viewed from a direction perpendicular to the substrate surface, V is as shown by a solid line L1 in FIG.
-T characteristic is obtained. That is, the transmittance of light decreases as the applied voltage value increases, and the transmittance becomes almost zero at a certain applied voltage value, and the transmittance remains almost zero even when the applied voltage is further increased. . In addition, the normal viewing angle direction (FIG. 1)
When the viewing angle is inclined toward (θ1 side in FIG. 3), the VT characteristic becomes as shown by the solid line L2 in FIG. That is, as the applied voltage increases, the light transmittance decreases, and when a certain voltage value is reached, the transmittance increases in reverse, and then gradually decreases again. Therefore, an inversion phenomenon occurs in which the black and white of the image is inverted at a specific angle. This phenomenon is that the angle of incidence of light at a specific angle, that is, the inclination of the liquid crystal molecules to the viewing angle becomes the same, the anisotropy of the refractive index of the liquid crystal molecules is lost,
This is because the optical rotation of light is lost. In particular, it appears significantly when the viewing angle is 20 ° or more.
Contrary to the above, the reverse viewing angle direction (θ2 side in FIG. 13)
When the viewing angle is inclined, the change in the refractive index of the liquid crystal molecules hardly occurs, so that the VT as shown by the solid line L3 in FIG.
Characteristics, and the black and white contrast is significantly reduced.

[0010] Therefore, when the above-mentioned inversion phenomenon or contrast reduction occurs in the TN type liquid crystal display device, it becomes a serious obstacle for an observer, and there is a question whether the display characteristics of the liquid crystal display device are inferior. Result.

Therefore, a technique proposed for improving display characteristics is known (Japanese Patent Laid-Open No. 2-12). This technique is used in an active matrix type liquid crystal display device.
By dividing the display electrode constituting the pixel into a plurality of parts and coupling a capacitor to each divided display electrode,
This is a technique in which different electric fields are generated in one pixel so that alignment states can be formed in a plurality of directions, and the viewing angle characteristics can be improved. However, the method of driving by dividing the display pixels in this manner is effective in improving the viewing angle characteristics due to a change in retardation, as seen in a liquid crystal display device of a normally black mode, but due to the inclination of liquid crystal molecules. It has little effect on the halftone reversal phenomenon that occurs. In other words, although this is effective for improving the viewing angle characteristics of a normally black mode liquid crystal display device, it is not effective for a normally white mode liquid crystal display device having excellent contrast.

The following technique is known as another method for improving the reversal phenomenon and the reduction in contrast.
In this technique, a rubbing process is performed in a state masked by a photolithography method, and the masking region is set in a non-aligned state and the non-masked region is set in an aligned state. Is formed. According to this technique, since one pixel can be formed in a state where the normal viewing angle direction and the reverse viewing angle direction are mixed, it is possible to prevent a decrease in contrast in the reverse viewing angle direction. However, according to this technique, a photolithography process is required, so that the display quality and reliability of the liquid crystal display device are reduced.

Further, in either of the above two techniques, there is a problem that the manufacturing cost increases because the number of manufacturing steps of the liquid crystal display device increases.

The present invention has been made to solve the above-mentioned conventional problems, and provides a liquid crystal display device capable of improving display quality at low cost and applicable to a normally white mode. With the goal.

[0015]

According to the present invention, there is provided a liquid crystal display device comprising: a pair of substrates provided with a liquid crystal layer interposed therebetween;
A liquid crystal display device having a plurality of pixels each provided with an electrode on the liquid crystal layer side of the plate, wherein one or both of the pixels are provided.
A board square, the whole or part of the portion corresponding to each pixel between the electrode and the liquid crystal layer provided on the substrate, the linear insulating film, an average value in a direction facing the long sides each part, on the substrate Is provided so as to intersect with the average value of the orientation direction of the liquid crystal molecules projected on the linear insulating film.
The liquid crystal molecules and the liquid in the liquid crystal layer portion adjacent to the liquid crystal layer portion
Crystal molecules rise in the same direction when a voltage is applied.
Note that the rising angles are different.
Sign .

In this liquid crystal display device, the angle at which the average value in the direction in which the long sides of the linear insulating film face each other and the average value in the alignment direction of the liquid crystal molecules projected on the substrate are 7 °.
It is preferable that the angle be 0 degrees or more and 110 degrees or less. The linear insulating film can be formed linearly or wavy.

Further, it is preferable that the line width or the interval between the linear insulating films is equal to or smaller than the interval between the pair of substrates.

Further, the film side surfaces on both long sides of the linear insulating film are formed in a tapered shape, and the alignment direction of the liquid crystal molecules in the liquid crystal layer portion corresponding to one film side surface of the both long sides and the other film side surface. , The liquid crystal molecules in the liquid crystal layer portion corresponding to the above may be arranged in the opposite direction. It is preferable that the line width of the linear insulating film is 0.5 μm or more and 12 μm or less, and the interval between the linear insulating films is 0 μm or more and twice or less of the line width. The tapered side surface of the film may have an angle of 1 degree or more and 45 degrees or less with respect to the substrate surface. The pretilt angle of the liquid crystal molecules can be 1 degree or less.

A second linear insulating film made of the same material as the linear insulating film may be provided between the linear insulating films in a state where the thickness is smaller than that of the linear insulating film. A third linear insulating film made of a material different from that of the linear insulating film may be provided between the linear insulating films. The third linear insulating film may be composed of two or more linear insulating films made of different materials.

Further, the linear insulating film may be formed on both of the pair of substrates so that the opposing positions are shifted in the width direction.

The adjacent ones of the linear insulating films may be formed so as to be connected at one end or both ends in the long side direction.

[0022]

In the present invention, the linear insulating film is formed by intersecting the average value in the direction of each long side of the linear insulating film with the average value in the alignment direction of the liquid crystal molecules projected on the substrate. Have been. Therefore, when a voltage is applied to the liquid crystal layer, the angle at which the liquid crystal molecules rise according to the applied voltage in the liquid crystal layer portion where the linear insulating film does not exist, and the liquid crystal under the same conditions in the liquid crystal layer portion where the linear insulating film exists. The angle at which the molecule rises is different. Since the portions where the rising angles are different exist in the pixels, the alignment state of the liquid crystal molecules differs in one pixel.

Such an orientation state is not limited to the case where the insulating film is formed in a linear shape, but can be ensured by changing the thickness or the material.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings.

(Embodiment 1) FIG.
FIG. 2 is a sectional view showing a part of an N-type active matrix liquid crystal display device, and FIG. 2 is a plan view showing an active matrix substrate constituting the liquid crystal display device. This liquid crystal display device has an active matrix substrate 31 disposed oppositely.
A liquid crystal layer 33 is sealed between the substrate and the counter substrate 32,
The active matrix substrate 31 includes a glass substrate 31a.
A transparent electrode (pixel electrode) 31c and a linear insulating film 31d are formed thereon.
And an alignment film 31e. On the counter substrate 32, a color filter 32b and a transparent electrode 3 are formed on a glass substrate 32a.
2c and an alignment film 32e are formed. Liquid crystal layer 33
Are oriented so as to be twisted by 90 ° between the substrates 31 and 32. The ends (not shown) of the substrates 31 and 32 are sealed with resin or the like, and peripheral circuits (not shown) and the like are mounted.

As shown in FIG. 1, an active matrix substrate 31 is provided on an insulating substrate 31a made of glass.
The scanning lines 12 and the signal lines 13 are provided to cross each other. A thin film transistor (hereinafter, referred to as a TFT) 20 as a switching element is formed near a portion where the scanning line 12 and the signal line 13 intersect. In this embodiment, the TFT 20 is an amorphous silicon TFT
And The TFT 20 can be formed on the scanning line 12.

Each TFT 20 is connected to a plurality of pixel electrodes 31c formed in a matrix and is electrically connected to one scanning line 12 and one signal line 13. The connection of the TFT 20 to the scanning line 12 is
And the connection to the signal line 13 of the TFT 20 is branched from the signal line 13 so as to have a part above the gate electrode 15. This is performed by the source electrode 16 and T
The connection of the FT 20 to the pixel electrode 31c is made by the gate electrode 15
Is performed by a drain electrode 17 having a portion above the drain electrode 17.

The pixel electrode 31c overlaps with the scanning line 12 adjacent to the scanning line 12 connected to the TFT 20, and the overlapping portion forms the additional capacitance 18. This additional capacity 18
However, the present invention is not limited to this, and an additional capacitance wiring may be provided separately from the scanning line 12 and formed thereon.

A plurality of linear insulating films 31d are juxtaposed on the pixel electrode 31c except for the portion where the additional capacitance 18 is formed. This linear insulating film 31d is formed for improving the viewing angle dependency, and the linear insulating film 31d is formed.
Due to the presence of d, prevention of short circuit due to foreign matter mixed in the liquid crystal layer and stabilization of TFT characteristics are achieved. Linear insulating film 3
The formation of 1d is performed, for example, by forming a silicon nitride film having a thickness of 600 nm on almost the entire surface of the insulating substrate 31a by a CVD method and patterning it linearly by a photolithography method. At this time, the linear insulating film 31
d is the average value of the direction in which each part of the long side faces the substrate 31a.
It is formed so as to intersect with the average value of the alignment direction of the liquid crystal molecules projected above. Preferably, it is formed so as to fall within a range of 90 degrees ± 20 degrees. Note that the patterning of the linear insulating film 31d can be generally performed in the same step as the patterning of the insulating protective film formed between the pixel electrode 31c and the liquid crystal layer 33. Does not need to be increased.

On the substrate 31a on which the linear insulating film 31d is formed, an alignment film 31e (not shown) for controlling the alignment state of the liquid crystal molecules is formed and rubbed.

In the liquid crystal display device of the present embodiment configured as described above, the linear insulating films 31d are provided side by side, and the average value of the long sides of the linear insulating films 31d in the direction in which each part is directed is: It intersects with the average value of the alignment direction of the liquid crystal molecules projected on the substrate. For this reason, as shown in FIG.
When a voltage is applied between the pixel electrode 31c and the transparent electrode 32c sandwiching the, the electric field intensity applied to the liquid crystal layer differs between the liquid crystal layer portion where the linear insulating film 31d does not exist and the liquid crystal layer portion where the linear insulating film 31d exists. . As a result, the linear insulating film 3
Liquid crystal layer portion where 1d does not exist, that is, linear insulating film 31d
The angle (arrow) at which the liquid crystal molecules rise in accordance with the applied voltage in the interval b portion and the liquid crystal layer portion where the linear insulating film 31d exists, that is, in the line width a portion of the linear insulating film 31d, under the same conditions. Is different from the rising angle (arrow).

The above-mentioned portions having different rising angles are 1
Since it exists in a pixel, the alignment state of liquid crystal molecules differs in one pixel. At this time, light (a large arrow in FIG. 2) obliquely incident on the liquid crystal display device passes through a plurality of liquid crystal layers in different alignment states, and the optical rotation is not completely lost. The inversion phenomenon can be suppressed, and the viewing angle dependency can be improved even in a normally white mode liquid crystal display device. The angle at which the average value in the direction in which the long sides of the linear insulating film 31d face each other and the average value in the alignment direction of the liquid crystal molecules projected on the substrate are set to 90 degrees ± 20 degrees. This is preferable for improving the viewing angle dependency.

In particular, by setting the line width a or the interval b of the linear insulating film 31d to be equal to or less than the thickness d of the liquid crystal layer 33, it is possible to improve a viewing angle characteristic of 20 ° or more at which halftone reversal phenomenon is remarkably exhibited. Can be. Preferably, it is good to be d / 2.7 or less.

In this embodiment, silicon nitride is used as the material of the linear insulating film 31d. However, the material is not limited to this, and an inorganic insulating film made of aluminum, tantalum or silicon oxide, or a nitride thereof, An organic insulating film made of polyimide, polyamide, or polystyrene can also be used. The same applies to the insulating protective film.

When the above-mentioned organic insulating film is used, a film having a thickness of about 100 nm can be formed by, for example, screening printing, and then patterned by a photodecomposition reaction using deep UV (wavelength 250 nm) or the like or a photolithography method. . Further, patterning can be performed by printing. This organic insulating film can also be used as an alignment film 31e.

(Embodiment 2) In this embodiment, a wavy linear insulating film is used in place of a linear insulating film.

FIG. 3 is a plan view showing an active matrix substrate 31 on which a wavy linear insulating film 31d is formed. 1 are given the same reference numerals. Also in this case, although the direction in which the long sides of the linear insulating film 31d face differs at the long side positions, the average value in the direction in which the long sides face is the orientation of the liquid crystal molecules projected on the substrate 31a. It is formed so as to intersect the average value in the direction. In this manner, by defining the linear insulating film 31d as described in the claims, it is possible to eliminate the viewing angle dependency as in the first embodiment.

In this embodiment, the linear insulating film is formed as a wavy line. However, the linear insulating film may be formed as a triangular wave or another curved linear insulating film.

(Embodiment 3) In this embodiment, both side surfaces of the long side of the linear insulating film are formed in a tapered shape.

FIG. 4 is a sectional view showing a liquid crystal display device according to this embodiment. This liquid crystal display device has a linear insulating film 3
Both film side surfaces of both long sides of 1d are formed in a tapered shape. The tapered side surface of the linear insulating film 31d can be formed by utilizing the isotropic etching, the etching back phenomenon of the resist material, and the like.

In this case, by making the pretilt angle of the liquid crystal molecules smaller than the taper angle of the film side surface,
As shown in FIG. 4, the liquid crystal molecules can be in a state of having a tilt angle in the opposite direction due to the taper of the film side surface.
The viewing angle dependency by the normal viewing angle and the reverse viewing angle can be eliminated. On the other hand, when the pretilt angle of the liquid crystal molecules is equal to or greater than the taper angle of the film side surface, the halftone inversion phenomenon is suppressed to improve the viewing angle dependence of the liquid crystal display device, as in the liquid crystal display device shown in FIG. can do.

It is preferable that the taper angle be 1 degree or more and 45 degrees or less with respect to the substrate surface. With such an angle, it is possible to more surely have a pretilt angle in the forward direction and the reverse direction, and it is possible to efficiently eliminate the viewing angle dependency due to the normal viewing angle and the reverse viewing angle.

Further, it is preferable that the pretilt angle be 1 degree or less. As described above, in addition to setting the pretilt angle to 1 degree or less, the setting of the line width a and the interval b of the linear insulating film 31d is desirably 0.5 μm ≦ a.
≦ 12 μm, and the interval b is preferably set to satisfy 0 <b ≦ 2a. The angle between the average value of the direction in which the long sides of the linear insulating film 31d is directed and the rubbing direction of the alignment film 31e for controlling the alignment state of the liquid crystal molecules is 90 ° ± 20 °.
Setting within ゜ makes it possible to further eliminate the viewing angle dependency.

(Embodiment 4) In this embodiment, a second linear insulating film made of the same material is formed also in the space between the linear insulating films.

FIG. 5 is a sectional view showing a liquid crystal display device according to this embodiment. In this liquid crystal display device, FIG.
The linear insulating film 31f is also formed at a portion corresponding to the interval b, and the thickness of the linear insulating film 31f is smaller than the thickness of the linear insulating film 31d formed at the portion corresponding to the line width a. Has become. That is, the insulating film is formed on almost the entire surface of the substrate with different thicknesses. The linear insulating film 3
1d indicates that the average value in the direction in which each part of the long side faces the substrate 31
The liquid crystal molecules are formed so as to intersect with the average value of the alignment direction of the liquid crystal molecules projected on a. Naturally, the linear insulating film 31f is formed in the same manner.

In this case, even if an insulating film is formed on almost the entire surface of the substrate, the linear insulating film 31f is
d, the electric field strength passing through the linear insulating film 31f is reduced even when a voltage is applied to the pixel electrode 31c and the transparent electrode 32c sandwiching the liquid crystal layer 33.
It becomes stronger than 1d. For this reason, the angle (arrow) at which the liquid crystal molecules rise in accordance with the applied voltage in the interval b.
And the angle (arrow) at which the liquid crystal molecules rise under the same conditions in the line width a portion, and the viewing angle dependency can be eliminated.

In this embodiment, the linear insulating film 31f is thinner than the linear insulating film 31d. However, the present invention is not limited to this, and the linear insulating film 31f is thicker than the linear insulating film 31d. May be. The point is that the insulating films may be formed in different thicknesses.

(Embodiment 5) In this embodiment, a third linear insulating film made of a different material is formed also in the space between the linear insulating films.

FIG. 6 is a sectional view showing a liquid crystal display device according to this embodiment. In this liquid crystal display device, FIG.
The linear insulating film 31g is also formed in a portion corresponding to the interval b, and the material of the linear insulating film 31g is different from that of the linear insulating film 31d formed in the portion corresponding to the line width a. I'm making it. More specifically, for example, silicon nitride of silicon nitride and tantalum oxide having different dielectric constants is used for the linear insulating film 31g, and tantalum oxide is used for the linear insulating film 31d.
Used for Note that the linear insulating film 31d is formed such that the average value in the direction of each long side crosses the average value in the alignment direction of the liquid crystal molecules projected on the substrate 31a. Of course, the linear insulating film 31g is formed in the same manner.

In this case, even if the insulating film is formed on almost the entire surface of the substrate, the linear insulating film 31g is replaced with the linear insulating film 31g.
Since the dielectric constant is higher than d, the liquid crystal layer 3
Even when a voltage is applied to the pixel electrode 31c and the transparent electrode 32c sandwiching 3, the electric field intensity passing through the linear insulating film 31g becomes stronger than that of the linear insulating film 31d. For this reason, the angle (arrow) at which the liquid crystal molecules rise according to the applied voltage in the interval b and the angle (arrow) at which the liquid crystal molecules rise under the same conditions in the line width a are different from each other. Can be eliminated.

In this embodiment, the relative dielectric constant of the linear insulating film 31g is set higher than that of the linear insulating film 31d. However, the present invention is not limited to this, and the relative dielectric constant of the linear insulating film 31g may be increased. It may be lower than the linear insulating film 31d. Further, other characteristics may be changed instead of the relative permittivity. In short, it is only necessary that the insulating film is formed in a state where the electric field strength is different.

In this embodiment, the adjacent linear insulating films 31 are used.
Although one linear insulating film 31g is provided between d, two or more linear insulating films 31g having different relative dielectric constants and other characteristics may be provided.

(Embodiment 6) In this embodiment, a linear insulating film is formed on both substrates sandwiching a liquid crystal layer, and a linear insulating film provided on one substrate and a line provided on the other substrate are provided. This is a case where the position with the linear insulating film is shifted in the width direction of the linear insulating film.

FIG. 7 is a sectional view showing a liquid crystal display device according to this embodiment. In this liquid crystal display device, a linear insulating film 31d is formed on an active matrix substrate 31, a linear insulating film 32d is formed on a counter substrate 32, and the linear insulating films 31d and 32d have a width of the linear insulating film. It is shifted in the direction. The linear insulating films 31d and 32d are formed such that the average value in the direction of each long side crosses the average value in the alignment direction of the liquid crystal molecules projected on the substrate 31a.

In this case, the distance b between the linear insulating films 31d
Region where the portion and the interval b 'portion of the linear insulating film 32d face each other, the region where the interval b portion or the interval b' portion faces the linear insulating film 31d or 32d, and the linear insulating film 31d and the linear insulating film There are three regions facing the film 32d.
Therefore, the same effect as reducing the line width or interval of the linear insulating film 31d can be obtained.

(Embodiment 7) In this embodiment, both ends of the linear insulating film are connected.

FIG. 8 is a plan view showing the liquid crystal display device according to this embodiment, and FIG. 9 is a sectional view taken along line AA 'in FIG. 8 and 9, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals. In this liquid crystal display device, an insulating film 20 is formed so as to cover almost the entire display portion where the pixel electrodes 31c of the active matrix substrate 31 are formed in a matrix.
By removing the upper part of 1c by etching or the like and providing the linear opening 21, a linear insulating film 31d is formed. This linear insulating film 31d is in a state where both ends of adjacent ones are connected.

In this case, the portion where the linear openings 21 are formed corresponds to the interval b shown in FIG. 2, and the insulating film portion without the linear openings 21 corresponds to the line width a. Therefore, the same effect as in the first embodiment can be obtained. Further, since the linear insulating film 31d is formed in a tapered shape, the same effect as in the third embodiment can be obtained. Also, the linear insulating film 31d
Are formed so that the angle between the long side direction and the arrow 11 indicating the rubbing direction is in the range of 90 degrees ± 20 degrees.

It should be noted that also in the seventh embodiment, the above-described modifications from the second embodiment to the sixth embodiment can be applied, and the same effect can be obtained in each modification. is there.

In the seventh embodiment, both ends of the adjacent linear insulating film 31d are connected, but the present invention is not limited to this, and one end of the linear insulating film 31d is connected. It can also be implemented in such a manner. In this case, one ends to be connected may be alternately or randomly located.

Embodiments 1, 2, 3 and 7 described above
In the above, the insulating film is not formed between the adjacent linear insulating films 31d. However, the present invention is not limited to this. When the linear insulating film is tapered as shown in FIG. Alternatively, the adjacent linear insulating films 31d may be formed in contact with each other. Even in this case, the thin linear insulating film 31
A strong electric field is generated in the portion d, and the electric field can be weakened in the thick linear insulating film 31d.

In the case where the linear insulating film 31d is tapered, the third embodiment and the seventh embodiment have a configuration in which the upper surface of the linear insulating film 31d has no flat surface. As a matter of course, a structure having a flat surface on the upper surface of the linear insulating film 31d as shown in FIG. In addition, as shown in FIG.
Both sides of the linear insulating film 31d include a round shape.
In the case of this rounded tapered shape, the taper angle so as to be not less than 1 degree and not more than 45 degrees with respect to the substrate surface is defined by the average direction of the tangent of each part of the rounded portion and the substrate surface. The angle corresponds.

In each of Embodiments 1 to 7 described above, the active matrix type liquid crystal display device has been described. However, the present invention is not limited to this, and a configuration in which a non-linear electric element is not formed on one substrate, that is, a simple matrix The present invention can be similarly applied to a liquid crystal display device of the type.

[0064]

As is clear from the above description, according to the present invention, in a portion corresponding to one pixel, a linear insulating film, an insulating film made of a different material, or an insulating film is formed on an electrode. Are formed, the portions having different alignment states due to the different electric field strengths can be removed by one.
It can be formed in one pixel. Therefore, the inversion phenomenon in the normal viewing angle direction and the decrease in contrast in the reverse viewing angle direction can be prevented, and the viewing angle dependency can be improved. Further, since the halftone reversal phenomenon can be suppressed, the present invention can be applied to a normally white mode liquid crystal display device having excellent contrast. Furthermore, since the step of forming the linear insulating film can be performed simultaneously with the patterning of the insulating protective film formed between the electrode and the liquid crystal layer, there is no need to add a new manufacturing step. Thus, a low-cost, high-contrast, high-quality liquid crystal display device can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a part of a liquid crystal display device according to a first embodiment.

FIG. 2 is a plan view showing an active matrix substrate included in the liquid crystal display device of FIG.

FIG. 3 is a cross-sectional view illustrating a part of a liquid crystal display device according to a second embodiment.

FIG. 4 is a cross-sectional view illustrating a part of a liquid crystal display device according to a third embodiment.

FIG. 5 is a cross-sectional view illustrating a part of a liquid crystal display device according to a fourth embodiment.

FIG. 6 is a cross-sectional view illustrating a part of a liquid crystal display device according to a fifth embodiment.

FIG. 7 is a cross-sectional view illustrating a part of a liquid crystal display device according to a sixth embodiment.

FIG. 8 is a cross-sectional view illustrating a part of a liquid crystal display device according to a seventh embodiment.

FIG. 9 is a sectional view taken along line AA ′ of FIG. 8;

FIG. 10 is a cross-sectional view illustrating a liquid crystal display device of the present invention, in which adjacent linear insulating films are formed in contact with each other.

FIG. 11 is a cross-sectional view showing another embodiment of a linear insulating film having both sides tapered in the liquid crystal display device of the present invention.

FIG. 12 is a cross-sectional view showing still another embodiment of a linear insulating film having both sides tapered in the liquid crystal display device of the present invention.

FIG. 13 is a cross-sectional view illustrating a configuration of a conventional liquid crystal display device.

FIG. 14 is a graph showing an applied voltage-transmittance characteristic (VT characteristic) in a conventional liquid crystal display device.

[Explanation of symbols]

 11 Arrow indicating rubbing direction 12 Scan line 13 Signal line 15 Gate electrode 16 Source electrode 17 Drain electrode 18 Additional capacitance 20 TFT 31a, 32a Transparent substrate 32b Color filter 31c Transparent electrode (pixel electrode) 32c Transparent electrode (opposite electrode) 31d, 32d, 31f, 31g Insulating film 31e, 32e Alignment film 31 One substrate (active matrix substrate) 32 The other substrate (counter substrate) 33 Liquid crystal layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-137819 (JP, A) JP-A-6-43460 (JP, A) JP-A-6-43462 (JP, A) JP-A-6-43462 82784 (JP, A) JP-A-6-82785 (JP, A) JP-A-6-281938 (JP, A) JP-A-6-337419 (JP, A) JP-A-6-167711 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) G02F 1/1337 505 G02F 1/1333 505

Claims (13)

(57) [Claims] 1. A pair of substrates provided with a liquid crystal layer interposed therebetween.
A liquid crystal display device comprising a substrate and a plurality of pixels each provided with an electrode on the liquid crystal layer side of each substrate, wherein one or both substrates are provided on the substrate.
The whole or part of the portion corresponding to each pixel between the electrode and the liquid crystal layer, linear insulating film, the alignment direction of liquid crystal molecules an average value in a direction facing the long sides each section was projected onto the substrate Is provided so as to intersect with the average value of the linear insulating film.
Liquid crystal molecules in the liquid crystal layer portion of
The liquid crystal molecules in the part of the liquid crystal layer that is in contact
When voltage is applied, it rises in the same direction and
It is characterized in that each rising angle is different
The liquid crystal display device that. 2. A second linear insulating film made of the same material as the linear insulating film is provided between the adjacent linear insulating films in a state where the thickness is smaller than that of the linear insulating film. The liquid crystal display device according to claim 1, wherein 3. The liquid crystal display device according to claim 1, wherein a third linear insulating film made of a material different from that of the linear insulating film is provided between the adjacent linear insulating films. 4. The third linear insulating film is made of two different materials.
4. The liquid crystal display device according to claim 3, comprising at least one kind of linear insulating film. 5. An intersection angle between an average value in a direction of each long side portion of the linear insulating film and an average value of an alignment direction of liquid crystal molecules projected on a substrate is 70 degrees or more and 110 degrees or less. The liquid crystal display device according to claim 1. 6. The liquid crystal display device according to claim 1, wherein the linear insulating film is formed in a straight line or in a wavy line. 7. The liquid crystal display device according to claim 1, wherein a line width or an interval between the linear insulating films is equal to or less than an interval between the pair of substrates. 8. A liquid crystal display device having a nematic liquid crystal layer interposed therebetween.
Electrodes on the liquid crystal layer side of each substrate.
A liquid crystal display device having a plurality of pixels respectively provided.
In one or both substrates,
Corresponding to each pixel between the separated electrode and the liquid crystal layer
The whole or part of the linear insulation film
The average value of the orientation is calculated based on the orientation of the liquid crystal molecules projected on the substrate.
It is provided so as to intersect with the average value,
Both long sides of the edge film are tapered.
The liquid in the liquid crystal layer portion corresponding to one film side surface of the two long sides
Liquid crystal layer corresponding to the orientation direction of crystal molecules and the side of the other film
That the orientation direction of the liquid crystal molecules is reversed.
Characteristic liquid crystal display device. 9. The linear insulating film has a line width of 0.5 μm or more and 12 μm or less, and an interval between the linear insulating films is 0 μm.
9. The liquid crystal display device according to claim 8, wherein the line width is not more than twice the line width. 10. The liquid crystal display device according to claim 8, wherein the tapered film side surface is formed at an angle of 1 degree or more and 45 degrees or less with respect to the substrate surface. 11. The liquid crystal display device according to claim 8 , wherein the pretilt angle of the liquid crystal molecules is 1 degree or less. 12. A both of said pair of substrates, the linear insulating film is formed by shifting the position opposed in the width direction according
Item 10. A liquid crystal display device according to item 8 . 13. An adjacent one of the linear insulating films is
Claims that are connected at one end or both ends in the long side direction
Item 10. A liquid crystal display device according to item 8 .